2010 Cadillac Truck SRX FWD V6-3.0L Page 1850

2010 Cadillac Truck SRX FWD V6-3.0L Page 1850

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Description and Operation

Transmission Component and System Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and

Operation/AF40-6 - Automatic Transmission/Transmission Component and System Description)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ensure the transmission fluid temperature is between 50-80掳C (122-176掳F).

2. Operate the vehicle in 2nd gear long enough to ensure at least a 3掳C (5掳F) rise in oil temperature.

3. Place the gear selector in Reverse for 5 s and then idle vehicle for 5 s.

4. Observe the scan tool data Shift Solenoid Valve 2 parameter. The parameter should display ON.

Circuit/System Testing

Static Test

1. Ignition OFF, remove the K71 Transmission Control Module.

2. Test for 11-15 ohm between the Shift Solenoid Control circuit terminal 2 X2 and ground.

瀚慖f not within the specified range, test the wiring harness for internal short, or interruption. If the circuit test normal, replace the Q32B

Shift Solenoid Valve 2.

3. Test for infinite resistance between each terminal and the Shift Solenoid Control circuit terminal 2 X2.

瀚慖f less than the specified range, replace the wiring harness.

4. If all circuits test normal, test or replace the Q32B Shift Solenoid Valve 2. Verify the DTC does not reset.

瀚慖f the DTC resets, replace the K71 Transmission Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Control valve body replacement-Refer to Control Valve Body Replacement (See: Transmission and Drivetrain/Automatic

Transmission/Transaxle/Valve Body/Service and Repair/AF40-6 - Automatic Transmission/Control Valve Body Replacement) for

replacement, setup and programming.

* TCM-Refer to Control Module References (See: Testing and Inspection/Programming and Relearning) for replacement, setup and

programming.

* Perform the Transmission Adaptive Functions (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and

Operation/AF40-6 - Automatic Transmission/Transmission Adaptive Functions).

* Wiring harness-Refer to Automatic Transmission Wiring Harness Replacement (See: Transmission and Drivetrain/Automatic

Transmission/Transaxle/Wiring Harness/Service and Repair) for replacement.

P0976

DTC P0976 or P0977

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

2010 Cadillac Truck SRX FWD V6-3.0L Page 1242

2010 Cadillac Truck SRX FWD V6-3.0L Page 1242

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Observe the DTC information with a scan tool. DTC P0171, P0172, P0174, or P0175 should not be set.

2. Engine running, observe the DTC information with a scan tool. Verify there are no HO2S DTCs set.

瀚慖f any HO2S DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).

3. Ignition ON, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor pressure should be within the range specified

for your altitude. Refer to Altitude Versus Barometric Pressure (See: Powertrain Management/Computers and Control

Systems/Specifications/Altitude Versus Barometric Pressure).

瀚慖f not the specified range, refer to DTC P0106 (LF1) (See: P Code Charts/P0106).

Note: EVAP purge enablement may cause the FT to be momentarily outside the normal range.

4. Allow the engine to reach operating temperature. With the engine running, observe the affected Long Term FT parameter with a scan tool.

The value should be between -20 % and +20 %.

瀚慖f not the specified range, inspect for the following:

P0171 or P0174

* A mass air flow (MAF) sensor signal that is skewed-If the Short Term FT parameters for both banks changes greater than 20 % when the

MAF sensor is disconnected, refer to DTC P0101 (LAU) (See: P Code Charts/P0101)DTC P0101 (LF1) (See: P Code Charts/P0101).

* Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool) (See: Powertrain Management/Fuel Delivery and

Air Induction/Fuel/Testing and Inspection/Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool))Alcohol/Contaminants-in-Fuel

Diagnosis (Without Special Tool) (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component

Tests and General Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)).

* Missing, restricted, or leaking exhaust components-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust

System/Testing and Inspection/Symptoms - Engine Exhaust).

* Malfunctioning fuel injectors-Refer to Fuel Injector Solenoid Coil Test (LAU) (See: Powertrain Management/Fuel Delivery and Air

Induction/Fuel Injector/Testing and Inspection)Fuel Injector Solenoid Coil Test (LF1, LFW) (See: Powertrain Management/Fuel

Delivery and Air Induction/Fuel Injector/Testing and Inspection).

* Vacuum hoses for splits, kinks, and improper connections

* Insufficient fuel in the tank

* Low fuel pressure-Refer to Fuel System Diagnosis (LF1 China) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel

Pump/Testing and Inspection/Fuel System Diagnosis (China))Fuel System Diagnosis (LF1 Except China) (See: Powertrain

Management/Fuel Delivery and Air Induction/Fuel Pump/Testing and Inspection/Fuel System Diagnosis (Except China))Fuel System

Diagnosis (LAU China) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Testing and Inspection/Fuel System

Diagnosis (China))Fuel System Diagnosis (LAU Except China) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel

Pump/Testing and Inspection/Fuel System Diagnosis (Except China)).

* Vacuum leaks at the intake manifold, the throttle body, and the injector O-rings.

* The air induction system and the air intake ducts for leaks, or for a missing air filter element

* A cracked EVAP canister

* Evaporative pipes obstructed or leaking

* The crankcase ventilation system for leaks

P0172 or P0175

* A mass air flow (MAF) sensor signal that is skewed-If the Short Term FT parameters for both banks changes greater than 20 % when the

MAF sensor is disconnected, refer to DTC P0101 (LAU) (See: P Code Charts/P0101)DTC P0101 (LF1) (See: P Code Charts/P0101).

* Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool) (See: Powertrain Management/Fuel Delivery and

Air Induction/Fuel/Testing and Inspection/Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool))Alcohol/Contaminants-in-Fuel

Diagnosis (Without Special Tool) (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component

Tests and General Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)).

* Missing, restricted, or leaking exhaust components-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust

2010 Cadillac Truck SRX FWD V6-3.0L Page 787

2010 Cadillac Truck SRX FWD V6-3.0L Page 787

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool References

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify DTC C056E is not set.

If the DTC is set, program the control module. If the DTC resets, replace the control module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and programming

C078A

DTC C078A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC C078A 39

- Tire Pressure Indicator Module Internal Malfunction

Circuit/System Description

The internal fault detection is handled inside the tire pressure sensor locator module. No external circuit diagnosis is involved.

Conditions for Running the DTC

The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This

program runs even if the voltage is out of the valid operating range.

Conditions for Setting the DTC

The module has detected an internal malfunction.

Action Taken When the DTC Sets

The module refuses all additional inputs.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.

* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

Diagnostic Aids

* This DTC may be stored as a history DTC without affecting the operation of the module.

* If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

* If this DTC is retrieved as both a current and history DTC, replace the tire pressure sensor locator module.

2010 Cadillac Truck SRX FWD V6-3.0L Page 2169

2010 Cadillac Truck SRX FWD V6-3.0L Page 2169

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool References

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify the appropriate DTC is not set.

If the DTC is set, program the control module specified by the DTC descriptor. If the DTC resets, replace the control module specified by the DTC

descriptor.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and programming

U0301

DTC U0300-U0336

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC U0301 00

- Software Incompatibility with Engine Control Module

DTC U0302 00

- Software Incompatibility with Transmission Control Module

DTC U0315 00

- Software Incompatibility with Electronic Brake Control Module

Circuit/System Description

Some control modules must be configured with specific software, serial numbers, vehicle options, or other information. If a control module was not

properly configured after installation that module may set the appropriate U Code. No external circuit diagnosis is involved.

Conditions for Running the DTC

Battery voltage is between 9-16 V and data link communications operate normally.

Conditions for Setting the DTC

The control module is not configured properly.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.

* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

2010 Cadillac Truck SRX FWD V6-3.0L Page 1540

2010 Cadillac Truck SRX FWD V6-3.0L Page 1540

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information

Circuit/System Verification

Note: Because of normal system communications between the BCM and ECM, any immobilizer B-codes must be diagnosed prior to the diagnosis

of P-codes.

Perform the BCM immobilizer learn using the Body Control Module IMMO Function with Existing Transponder or Remote Key in SPS. Refer to

Immobilizer System Component Programming (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Testing and

Inspection/Programming and Relearning). The BCM should successfully complete the learn and the vehicle should start.

If vehicle starting is not restored, perform the ECM immobilizer learn using the Engine Control Module IMMO Learn in SPS. Refer to Immobilizer

System Component Programming (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Testing and Inspection/Programming

and Relearning).

P0520

DTC P0520

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions)provides an overview of each diagnostic category.

DTC Descriptor

DTC P0520

- Engine Oil Pressure Switch Circuit Malfunction

Diagnostic Fault Information

Typical Scan Tool Data

Circuit/System Description

The engine oil pressure switch is a normally closed switch that opens with the proper oil pressure. With the ignition switch turned ON and the

engine not running, the engine control module (ECM) should detect a low signal voltage input. With the engine running, the engine oil pressure

switch opens and the ECM should detect a high signal voltage input. When the oil pressure is low, the ECM sends a message via High Speed

CAN-Bus to the body control module (BCM). The BCM then sends a message via Low Speed CAN-Bus to the instrument cluster requesting the

engine oil pressure indicator turned ON.

2010 Cadillac Truck SRX FWD V6-3.0L Page 1172

2010 Cadillac Truck SRX FWD V6-3.0L Page 1172

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, observe the DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set.

瀚慖f a B52 HO2S heater DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).

2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the appropriate B52 HO2S harness connector.

2. Ignition ON, observe the appropriate scan tool HO2S voltage parameter. The parameter should display 1.27 V.

瀚慖f less than the specified range, test the high and low signal circuits for a short to ground. If both signal circuit test normal, replace the

K20 ECM.

3. Ignition ON, test for 2.5-3.0 V between the high signal circuit terminal B and ground.

瀚慖f less than the specified range, test the high signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

瀚慖f greater than the specified range, test the high signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition OFF, connect a 3 A fused jumper wire between the high signal circuit terminal B and the low signal circuit terminal A.

Note: The low signal circuit is tied to a pull-up circuit within the ECM. A voltage of 0.90-1.10 V on the low signal circuit is normal.

5. Ignition ON, verify the scan tool HO2S parameter displays 0.0 V.

瀚慖f greater than the specified range, test the low signal circuit for an open/high resistance or for a short to voltage. If the circuit tests

normal, replace the K20 ECM.

6. If all circuits test normal, test or replace the appropriate B52 HO2S.

Repair Instructions

Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution (See: Powertrain Management/Computers and Control

Systems/Oxygen Sensor/Service Precautions/Heated Oxygen Sensor Resistance Learn Reset Caution).

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen

Sensor/Service and Repair/Heated Oxygen Sensor Replacement - Bank 1 Sensor 1)

* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen

Sensor/Service and Repair/Heated Oxygen Sensor Replacement - Bank 1 Sensor 2)

* Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen

Sensor/Service and Repair/Heated Oxygen Sensor Replacement - Bank 2 Sensor 1)

* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen

Sensor/Service and Repair/Heated Oxygen Sensor Replacement - Bank 2 Sensor 2)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

2010 Cadillac Truck SRX AWD V6-3.0L Page 155

2010 Cadillac Truck SRX AWD V6-3.0L Page 155

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Verify that DTC B048D 01 or B048D 06 is not set.

瀚慖f DTC is present, refer to Electrical Auxiliary Heater Control Circuit Malfunction.

2. Verify that DTC B048E 00 is not set.

瀚慖f DTC is present, refer to Electrical Auxiliary Heater Signal Circuit Malfunction.

Circuit/System Testing

Electrical Auxiliary Heater Control Circuit Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module and the X1 harness connector at the E40 Electrical

Auxiliary Heater.

2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 2 X1 and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

3. Test for less than 0.3 V between the control circuit terminal 7 X2 at the K33 HVAC Control Module harness connector and ground.

瀚慖f greater than the specified range, test the control circuit for a short to voltage.

4. Ignition OFF, test for infinite resistance between the control circuit terminal 7 X2 at the K33 HVAC Control Module harness connector and

ground.

瀚慖f less than the specified value, test the control circuit for a short to ground.

5. Test for less than 5 ohm between the K33 HVAC Control Module control circuit terminal 7 X2 and control circuit terminal 1 X1 at the E40

Electrical Auxiliary Heater harness connector.

瀚慖f greater than the specified value, test the control circuit for an open/high resistance.

6. If all circuits test normal, replace the E40 Electrical Auxiliary Heater and verify the DTC does not reset.

Electrical Auxiliary Heater Signal Circuit Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module and the harness connectors at the E40 Electrical

Auxiliary Heater.

2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 X2 at the E40 Electrical Auxiliary Heater harness connector

and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminal 1 X2 and ground circuit terminal 1 X3.

瀚慖f the test lamp does not illuminate, test the ground circuit for an open/high resistance.

4. Verify that a test lamp illuminates between the ignition circuit terminal 2 X1 and ground circuit terminal 1 X3.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

5. Test for less than 0.3 V between the signal circuit terminal 5 X2 at the K33 HVAC Control Module harness connector and ground.

瀚慖f greater than the specified range, test the signal circuit for a short to voltage.

6. Ignition OFF, test for infinite resistance between the signal circuit terminal 5 X2 at the K33 HVAC Control Module harness connector and

ground.

瀚慖f less than the specified value, test the signal circuit for a short to ground.

2010 Cadillac Truck SRX AWD V6-3.0L Page 787

2010 Cadillac Truck SRX AWD V6-3.0L Page 787

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool References

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify DTC C056E is not set.

If the DTC is set, program the control module. If the DTC resets, replace the control module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and programming

C078A

DTC C078A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC C078A 39

- Tire Pressure Indicator Module Internal Malfunction

Circuit/System Description

The internal fault detection is handled inside the tire pressure sensor locator module. No external circuit diagnosis is involved.

Conditions for Running the DTC

The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This

program runs even if the voltage is out of the valid operating range.

Conditions for Setting the DTC

The module has detected an internal malfunction.

Action Taken When the DTC Sets

The module refuses all additional inputs.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.

* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

Diagnostic Aids

* This DTC may be stored as a history DTC without affecting the operation of the module.

* If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

* If this DTC is retrieved as both a current and history DTC, replace the tire pressure sensor locator module.

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2833

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2833

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2825

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2825

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2817

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2817

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2809

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2809

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2801

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2801

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2793

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2793

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2785

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2785

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2768

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2768

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2760

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2760

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2731

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2731

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2723

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2723

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2715

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2715

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC U1814, U2099, B1428, B1370, B1380, B1440, or B1441 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Note: Use the schematic to identify the following:

* Control modules the vehicle is equipped with

* Control module locations on the low and high speed GMLAN serial data circuits

* The control modules B+, ignition, ground, communication enable and serial data circuit terminals

1. Determine the control module that is not communicating. Refer to Control Module U Code List (See: Diagnostic Trouble Code

Descriptions/Control Module U Code List).

2. Ignition OFF, disconnect the harness connector of the control module that is not communicating.

3. Test for less than 10 ohm between each ground circuit terminal and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the

control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test

the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.

Note: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit,

and the BCM is the output for these circuits. Refer to the control module schematics to identify which control modules have these circuits.

6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup

circuit terminal and ground.

瀚慖f the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.

7. Ignition OFF for 60 seconds, test for less than 5 ohm between the serial data circuit terminals and the appropriate DLC terminal listed below:

* Class 2 serial data circuit terminal 2

* Low speed GMLAN serial data terminal 1

* High speed GMLAN serial data terminal 6 or 14

瀚慖f greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module

and a control module setting the DTC or a serial data splice pack.

8. If all circuits test normal, replace the control module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and