2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2059

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2059

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

Trouble Code (DTC) List - Vehicle).

2. Operate the vehicle within the Conditions for Running the DTC while observing the scan tool Catalyst monitor Not At Idle Test Conditions

Met parameter. The parameter will change to Yes when the OFF Idle Conditions have been met.

瀚慖f not the specified value, operate the vehicle within the OFF Idle Conditions.

3. When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.

4. Apply the service brake.

5. Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running.

6. Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed.

7. When the test has completed, the Catalyst Monitor Test Counter Bank 1 or Bank 2 parameter will increment by one and the Catalyst Monitor

Test Result Bank 1 or Bank 2 parameter will indicate Pass, Fail, or No Decision.

瀚慖f no decision has been made, repeat steps 2-6 until the Test Result parameter indicates a Pass or Fail.

Circuit/System Testing

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).

Note: A new converter with less than 161 km (100 mi) on it may set DTC P0420 or P0430 due to out-gassing of the internal matting.

Operating the vehicle at highway speeds for approximately 1 h may correct the condition.

1. Engine idling, observe the DTC information with a scan tool. Verify there are no HO2S or misfire DTCs set.

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

Trouble Code (DTC) List - Vehicle) to diagnosis the applicable DTC before proceeding with this diagnostic procedure.

2. Verify the following conditions do not exist with the catalytic converter:

* Dents

* A severe discoloration caused by excessive temperatures

* An internal rattle caused by damaged catalyst substrate

* Restrictions-Refer to Restricted Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and Inspection/Restricted Exhaust

).

瀚慖f a condition is found, replace the catalytic converter.

3. Verify the following conditions do not exist with the exhaust system:

* Leaks-Refer to Exhaust Leakage (See: Engine, Cooling and Exhaust/Exhaust System/Testing and Inspection/Exhaust Leakage).

* Physical damage

* Loose or missing hardware

* Improperly torqued HO2S

瀚慖f a condition is found, repair the exhaust system.

4. Verify the following conditions do not exist with the HO2S 2:

* A grounded wiring harness

* Damage

瀚慖f a condition is found, replace the HO2S 2.

5. If no physical condition is detected and the HO2S 2 is as active as the HO2S 1 after operating the engine at 1,500 RPM for 1 min and then

returning to a stabilized idle, then replace the catalytic converter.

Repair Instructions

Note: A new converter with less than 161 km (100 mi) on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating

the vehicle at highway speeds for approximately 1 hour may correct the condition.

* Exhaust Manifold Replacement - Left Side (See: Engine, Cooling and Exhaust/Exhaust System/Exhaust Manifold/Service and

Repair/Exhaust Manifold Replacement - Left Side)

* Exhaust Manifold Replacement - Right Side (See: Engine, Cooling and Exhaust/Exhaust System/Exhaust Manifold/Service and

Repair/Exhaust Manifold Replacement - Right Side)

* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (1500 Series) (See: Powertrain Management/Computers and Control

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1855

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1855

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

Trouble Code (DTC) List - Vehicle).

* Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S value

should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.

瀚慖f the value does not vary from approximately 40 mV to approximately 900 mV, refer to DTC P0131, P0132, P0137, P0138, P0151,

P0152, P0157, or P0158 (See: P Code Charts/P0131), DTC P0133, P013A-P013F, P014A, P014B, P0153, P1133, or P1153 ( See: P

Code Charts/P0133) or DTC P0134, P0140, P0154, or P0160 (See: P Code Charts/P0134).

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

* The normal Short Term FT parameter should be between +10 % and -10 %, with near 0 % the optimum, with the engine running at operating

temperature.

* The Long Term FT parameter should be between +10 % and -10 %, with near 0 % the optimum, with the engine running at operating

temperature.

* 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

P0171 or P0174

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

reading should be between 0-19 %.

If not within the specified range, inspect for the following:

* With the ignition ON and the engine OFF, 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).

瀚慠efer to DTC P0106 (See: P Code Charts/P0106) if the MAP sensor does not indicate the correct barometric pressure.

* With the engine idling, observe the mass air flow (MAF) sensor parameter. The MAF sensor parameter should be within 2-6 g/s at idle.

瀚慠efer to DTC P0101 or P1101 (See: P Code Charts/P0101) or DTC P0102 or P0103 (See: P Code Charts/P0102) if the MAF sensor

parameter is not within 2-6 g/s at idle.

* Vacuum hoses for splits, kinks, and improper connections

* Insufficient fuel in the tank

* Low fuel pressure-Refer to Fuel System Diagnosis (w/o FPCM) (See: Powertrain Management/Computers and Control Systems/Testing and

Inspection/Component Tests and General Diagnostics)Fuel System Diagnosis (FPCM) (See: Powertrain Management/Computers and

Control Systems/Testing and Inspection/Component Tests and General Diagnostics).

* Fuel contamination-Refer to 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))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)) for Gasoline or Fuel Composition Diagnosis

(See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics) for E85.

* Malfunctioning fuel injectors-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and

Inspection/Symptoms - Engine Exhaust).

* Missing, loose, or leaking exhaust components from the HO2S forward-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and

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

* 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

* The HO2S for improper installation and for electrical wires or connectors that may have contacted the exhaust system

* The HO2S signal circuit open, shorted to ground, or shorted to the low reference circuit

* Malfunctioning engine components-Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and

Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).

P0172 or P0175

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

reading should be between -19 and 0 %.

If not within the specified range, inspect for the following:

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1910

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1910

瀚慖f any other DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle) to diagnosis the applicable DTC.

2. Ignition ON, observe the barometric pressure (BARO) sensor pressure parameter and compare the reading on the scan tool to the barometric

pressure table. Refer to Altitude Versus Barometric Pressure (See: Powertrain Management/Computers and Control Systems/Specifications

).

瀚慖f the BARO sensor pressure is not within the range specified for your altitude, refer to DTC P2227, P2228, or P2229 (LLT) ( See: P

Code Charts/P2227).

3. Engine at normal operating temperature, observe the scan tool Long Term Fuel Trim parameters. The LT FT Cruise/Accel parameters should

be less than 33 %. The LT FT Idle/Decel parameters should be less than 7 %.

瀚慖f not within the specified range, verify none of the following conditions exist:

* The heated oxygen sensor (HO2S) is installed securely and the electrical connector is not contacting the exhaust system.

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

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

* The air intake system after the MAF sensor for vacuum leaks

* 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 (w/LLT) (See: P Code Charts/P0101)DTC P0101 (LF1) (See: P Code Charts/P0101).

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

and Control Systems/Testing and Inspection/Component Tests and General Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (with

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)) and Fuel System Cleaning (See: Powertrain Management/Fuel Delivery and Air Induction/Service and Repair).

* Splits, kinks, or improper connections at the vacuum hoses

* The fuel system is operating lean. Refer to Fuel System Diagnosis (See: Powertrain Management/Computers and Control

Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel System Diagnosis).

* Vacuum leaks at the intake manifold or throttle body

* Leaking crankcase ventilation system

* The engine control module grounds for being clean, tight, and in the correct locations

* A high engine oil level condition-A high engine oil level causes oil residue to form on the mass air flow (MAF) sensor, causing a lean

indication. The MAF sensor does not need to be replaced.

* Vacuum leaks that only affect one bank of the engine-For example, the intake manifold, the injector O-rings.

* Lean injectors-Refer to Fuel Injector Solenoid Coil Test (w/LLT) (See: Powertrain Management/Computers and Control

Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel Injector Solenoid Coil Test)Fuel Injector Solenoid Coil

Test (w/LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and Inspection).

* An engine mechanical condition-Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and

Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).

4. 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.

Repair Instructions

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

P2188

DTC P2178, P2180, P2188, or P2190 (w/LLT)

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 P2178

- Fuel Trim System Rich at Cruise or Acceleration Bank 1

DTC P2180

- Fuel Trim System Rich at Cruise or Acceleration Bank 2

2010 Cadillac Truck Escalade RWD V8-6.2L Page 2059

2010 Cadillac Truck Escalade RWD V8-6.2L Page 2059

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

Trouble Code (DTC) List - Vehicle).

2. Operate the vehicle within the Conditions for Running the DTC while observing the scan tool Catalyst monitor Not At Idle Test Conditions

Met parameter. The parameter will change to Yes when the OFF Idle Conditions have been met.

瀚慖f not the specified value, operate the vehicle within the OFF Idle Conditions.

3. When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.

4. Apply the service brake.

5. Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running.

6. Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed.

7. When the test has completed, the Catalyst Monitor Test Counter Bank 1 or Bank 2 parameter will increment by one and the Catalyst Monitor

Test Result Bank 1 or Bank 2 parameter will indicate Pass, Fail, or No Decision.

瀚慖f no decision has been made, repeat steps 2-6 until the Test Result parameter indicates a Pass or Fail.

Circuit/System Testing

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).

Note: A new converter with less than 161 km (100 mi) on it may set DTC P0420 or P0430 due to out-gassing of the internal matting.

Operating the vehicle at highway speeds for approximately 1 h may correct the condition.

1. Engine idling, observe the DTC information with a scan tool. Verify there are no HO2S or misfire DTCs set.

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

Trouble Code (DTC) List - Vehicle) to diagnosis the applicable DTC before proceeding with this diagnostic procedure.

2. Verify the following conditions do not exist with the catalytic converter:

* Dents

* A severe discoloration caused by excessive temperatures

* An internal rattle caused by damaged catalyst substrate

* Restrictions-Refer to Restricted Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and Inspection/Restricted Exhaust

).

瀚慖f a condition is found, replace the catalytic converter.

3. Verify the following conditions do not exist with the exhaust system:

* Leaks-Refer to Exhaust Leakage (See: Engine, Cooling and Exhaust/Exhaust System/Testing and Inspection/Exhaust Leakage).

* Physical damage

* Loose or missing hardware

* Improperly torqued HO2S

瀚慖f a condition is found, repair the exhaust system.

4. Verify the following conditions do not exist with the HO2S 2:

* A grounded wiring harness

* Damage

瀚慖f a condition is found, replace the HO2S 2.

5. If no physical condition is detected and the HO2S 2 is as active as the HO2S 1 after operating the engine at 1,500 RPM for 1 min and then

returning to a stabilized idle, then replace the catalytic converter.

Repair Instructions

Note: A new converter with less than 161 km (100 mi) on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating

the vehicle at highway speeds for approximately 1 hour may correct the condition.

* Exhaust Manifold Replacement - Left Side (See: Engine, Cooling and Exhaust/Exhaust System/Exhaust Manifold/Service and

Repair/Exhaust Manifold Replacement - Left Side)

* Exhaust Manifold Replacement - Right Side (See: Engine, Cooling and Exhaust/Exhaust System/Exhaust Manifold/Service and

Repair/Exhaust Manifold Replacement - Right Side)

* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (1500 Series) (See: Powertrain Management/Computers and Control

2010 Cadillac Truck Escalade RWD V8-6.2L Page 1855

2010 Cadillac Truck Escalade RWD V8-6.2L Page 1855

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

Trouble Code (DTC) List - Vehicle).

* Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S value

should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.

瀚慖f the value does not vary from approximately 40 mV to approximately 900 mV, refer to DTC P0131, P0132, P0137, P0138, P0151,

P0152, P0157, or P0158 (See: P Code Charts/P0131), DTC P0133, P013A-P013F, P014A, P014B, P0153, P1133, or P1153 ( See: P

Code Charts/P0133) or DTC P0134, P0140, P0154, or P0160 (See: P Code Charts/P0134).

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

* The normal Short Term FT parameter should be between +10 % and -10 %, with near 0 % the optimum, with the engine running at operating

temperature.

* The Long Term FT parameter should be between +10 % and -10 %, with near 0 % the optimum, with the engine running at operating

temperature.

* 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

P0171 or P0174

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

reading should be between 0-19 %.

If not within the specified range, inspect for the following:

* With the ignition ON and the engine OFF, 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).

瀚慠efer to DTC P0106 (See: P Code Charts/P0106) if the MAP sensor does not indicate the correct barometric pressure.

* With the engine idling, observe the mass air flow (MAF) sensor parameter. The MAF sensor parameter should be within 2-6 g/s at idle.

瀚慠efer to DTC P0101 or P1101 (See: P Code Charts/P0101) or DTC P0102 or P0103 (See: P Code Charts/P0102) if the MAF sensor

parameter is not within 2-6 g/s at idle.

* Vacuum hoses for splits, kinks, and improper connections

* Insufficient fuel in the tank

* Low fuel pressure-Refer to Fuel System Diagnosis (w/o FPCM) (See: Powertrain Management/Computers and Control Systems/Testing and

Inspection/Component Tests and General Diagnostics)Fuel System Diagnosis (FPCM) (See: Powertrain Management/Computers and

Control Systems/Testing and Inspection/Component Tests and General Diagnostics).

* Fuel contamination-Refer to 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))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)) for Gasoline or Fuel Composition Diagnosis

(See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics) for E85.

* Malfunctioning fuel injectors-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and

Inspection/Symptoms - Engine Exhaust).

* Missing, loose, or leaking exhaust components from the HO2S forward-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and

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

* 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

* The HO2S for improper installation and for electrical wires or connectors that may have contacted the exhaust system

* The HO2S signal circuit open, shorted to ground, or shorted to the low reference circuit

* Malfunctioning engine components-Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and

Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).

P0172 or P0175

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

reading should be between -19 and 0 %.

If not within the specified range, inspect for the following:

2010 Cadillac CTS Sedan AWD V6-3.6L Page 2002

2010 Cadillac CTS Sedan AWD V6-3.6L Page 2002

瀚慖f the DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle).

2. Ignition OFF, disconnect the harness connector at the G12 fuel pump.

3. Ignition ON, test for less than 5.0 ohm between the G12 fuel pump low reference circuit terminal 2 and ground.

瀚慖f greater than the specified range, test the G12 fuel pump low reference circuit for a high resistance. If the circuit tests normal, replace

the K27 fuel pump control module.

4. Ignition OFF, install a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.

5. Ignition ON, command the Fuel Pump Relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between

the commanded states.

瀚慖f the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control

module.

瀚慖f the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace

the K27 fuel pump control module.

6. Perform the Fuel System Diagnosis (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component

Tests and General Diagnostics/Fuel System Diagnosis) to verify proper fuel pressure.

瀚慖f the fuel pressure is not normal, replace the G12 fuel pump

7. If all circuits test normal, replace the K27 fuel pump control module.

Repair Instructions

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

* Fuel Tank Fuel Pump Module Replacement - Right Side (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Service

and Repair/Fuel Tank Fuel Pump Module Replacement - Right Side)

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

and programming

P2636

DTC P2636

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 P2636

- Fuel Pump 2 Flow Insufficient

Circuit Description

The fuel tank on this vehicle is equipped with 2 fuel level sensors, one for each reservoir of the fuel tank. Fuel is transferred from the left side of the

fuel tank to the right side of the fuel tank in order to ensure all of the usable fuel volume is available. The fuel pump supplies a small amount of

pressurized fuel to the siphon jet pump through the fuel feed pipe. The pressurized fuel creates a venturi action inside the siphon jet pump. The

venturi action causes the fuel to be drawn out of the left side of the fuel tank. Fuel is then transferred from the left side of fuel tank to the right side

of fuel tank through the internal fuel transfer tube. This diagnostic tests for too large of a difference in fuel level between the left and right side of

the fuel tank. The DTC sets if the control module determines that the right side fuel level is less than a predetermined amount of the left side fuel

level.

The following table illustrates the difference between fuel level, resistance, and voltage:

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1928

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1928

瀚慖f any other DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle) to diagnosis the applicable DTC.

2. Ignition ON, observe the barometric pressure (BARO) sensor pressure parameter and compare the reading on the scan tool to the barometric

pressure table. Refer to Altitude Versus Barometric Pressure (See: Powertrain Management/Computers and Control Systems/Specifications

).

瀚慖f the BARO sensor pressure is not within the range specified for your altitude, refer to DTC P2227, P2228, or P2229 (LLT) ( See: P

Code Charts/P2227).

3. Engine at normal operating temperature, observe the scan tool Long Term Fuel Trim parameters. The LT FT Cruise/Accel parameters should

be greater than -23 %. The LT FT Idle/Decel parameters should be greater than -7 %.

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

* 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 (w/LLT) (See: P Code Charts/P0101)DTC P0101 (LF1) (See: P Code Charts/P0101).

* A collapsed air intake duct

* A restricted air filter element-Refer to Air Cleaner Element Replacement (LLT) (See: Engine, Cooling and Exhaust/Engine/Tune-up and

Engine Performance Checks/Air Cleaner Housing/Air Filter Element/Service and Repair)Air Cleaner Element Replacement (LSA) (See:

Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Air Cleaner Housing/Air Filter Element/Service and

Repair)Air Cleaner Element Replacement (LF1) (See: Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance

Checks/Air Cleaner Housing/Air Filter Element/Service and Repair).

* The MAF sensor for foreign objects-Refer to Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (LLT) (See:

Powertrain Management/Computers and Control Systems/Air Temperature Sensor ( Ambient / Intake )/Service and Repair)Mass Airflow

Sensor with Intake Air Temperature Sensor Replacement (LSA) (See: Powertrain Management/Computers and Control Systems/Air

Temperature Sensor ( Ambient / Intake )/Service and Repair)Mass Airflow Sensor with Intake Air Temperature Sensor Replacement

(LF1) (See: Powertrain Management/Computers and Control Systems/Air Temperature Sensor ( Ambient / Intake )/Service and Repair).

* Excessive fuel in the crankcase-Change the oil as necessary.

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

and Control Systems/Testing and Inspection/Component Tests and General Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (with

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)) and Fuel System Cleaning (See: Powertrain Management/Fuel Delivery and Air Induction/Service and Repair).

* The engine control module grounds for being clean, tight, and in the correct locations

* Rich injectors-Refer to Fuel Injector Solenoid Coil Test (w/LLT) (See: Powertrain Management/Computers and Control

Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel Injector Solenoid Coil Test)Fuel Injector Solenoid Coil

Test (w/LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and Inspection).

* Restricted exhaust system-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and

Inspection/Symptoms - Engine Exhaust).

* An engine mechanical condition-Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and

Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).

4. 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.

Repair Instructions

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

P2187

DTC P2177, P2179, P2187, or P2189 (w/LLT)

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 P2177

- Fuel Trim System Lean at Cruise or Acceleration Bank 1

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1956

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1956

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

Trouble Code (DTC) List - Vehicle).

* Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S value

should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.

锟斤拷If the value does not vary from approximately 40 mV to approximately 900 mV, refer to DTC P0131, P0132, P0137, P0138, P0151,

P0152, P0157, or P0158 (See: P Code Charts/P0131), DTC P0133, P013A-P013F, P014A, P014B, P0153, P1133, or P1153 ( See: P

Code Charts/P0133) or DTC P0134, P0140, P0154, or P0160 (See: P Code Charts/P0134).

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

* The normal Short Term FT parameter should be between +10 % and -10 %, with near 0 % the optimum, with the engine running at operating

temperature.

* The Long Term FT parameter should be between +10 % and -10 %, with near 0 % the optimum, with the engine running at operating

temperature.

* 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

P0171 or P0174

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

reading should be between 0-19 %.

If not within the specified range, inspect for the following:

* With the ignition ON and the engine OFF, 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).

锟斤拷Refer to DTC P0106 (See: P Code Charts/P0106) if the MAP sensor does not indicate the correct barometric pressure.

* With the engine idling, observe the mass air flow (MAF) sensor parameter. The MAF sensor parameter should be within 2-6 g/s at idle.

锟斤拷Refer to DTC P0101 or P1101 (See: P Code Charts/P0101) or DTC P0102 or P0103 (See: P Code Charts/P0102) if the MAF sensor

parameter is not within 2-6 g/s at idle.

* Vacuum hoses for splits, kinks, and improper connections

* Insufficient fuel in the tank

* Low fuel pressure-Refer to Fuel System Diagnosis (w/o FPCM) (See: Powertrain Management/Computers and Control Systems/Testing and

Inspection/Component Tests and General Diagnostics)Fuel System Diagnosis (FPCM) (See: Powertrain Management/Computers and

Control Systems/Testing and Inspection/Component Tests and General Diagnostics).

* Fuel contamination-Refer to 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))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)) for Gasoline or Fuel Composition Diagnosis

(See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics) for E85.

* Malfunctioning fuel injectors-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and

Inspection/Symptoms - Engine Exhaust).

* Missing, loose, or leaking exhaust components from the HO2S forward-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and

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

* 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

* The HO2S for improper installation and for electrical wires or connectors that may have contacted the exhaust system

* The HO2S signal circuit open, shorted to ground, or shorted to the low reference circuit

* Malfunctioning engine components-Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and

Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).

P0172 or P0175

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

reading should be between -19 and 0 %.

If not within the specified range, inspect for the following: