2010 Cadillac CTS Sedan AWD V6-3.6L Page 952

2010 Cadillac CTS Sedan AWD V6-3.6L Page 952

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 tests normal and

the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

3. Connect a test lamp between the heater control circuit terminal C and B+. The test lamp should not illuminate.

瀚慖f the test lamp is always ON, test the control circuit for a short to ground. If the circuit/connections test normal, replace the ECM.

Note: The control circuit for the HO2S heater is pulled-up to voltage within the ECM, 2.0-3.0 volts on the control circuit is normal.

4. Idle the engine, and verify the test lamp illuminates or flashes.

瀚慖f the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.

5. Ignition ON, test for 2.0-3.0 V between the control circuit terminal C and ground.

瀚慖f not within the specified range, test the control circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

6. If all circuits/connections test normal, test or replace the HO2S sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the heated oxygen sensor (HO2S) sensor.

2. Test for 5-25 ohm between the terminals C and D of the HO2S.

瀚慖f not within the specified range, replace the HO2S sensor.

Repair Instructions

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 (LLT) (See: Powertrain Management/Computers and

Control Systems/Oxygen Sensor/Service and Repair)

* 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 (LLT) (See: Powertrain Management/Computers and

Control Systems/Oxygen Sensor/Service and Repair)

* 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 (LLT) (See: Powertrain Management/Computers and

Control Systems/Oxygen Sensor/Service and Repair)

* 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 (LLT) (See: Powertrain Management/Computers and

Control Systems/Oxygen Sensor/Service and Repair)

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

programming

P0057

DTC P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, or P0058 (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 P0030

- HO2S Heater Control Circuit Bank 1 Sensor 1

DTC P0031

- HO2S Heater Control Circuit Low Voltage Bank 1 Sensor 1

DTC P0032

- HO2S Heater Control Circuit High Voltage Bank 1 Sensor 1

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 998

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 998

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 tests normal and

the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.

3. Connect a test lamp between the control circuit terminal 2 and the ignition circuit terminal 1.

Note: If any Turbocharger circuit DTC is set, the Bypass Solenoid Valve output control may not function. It may be necessary to clear the

DTCs with a scan tool to enable the output control.

4. Command the Turbocharger Bypass Solenoid Valve between Inactive and Active with a scan tool, then select exit. The test lamp should

illuminate and then go OFF.

瀚慖f the test lamp is always ON, test the control circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K20 ECM.

瀚慖f the test lamp is always OFF, test the control circuit terminal 2 for a short to voltage or an open/high resistance. If the circuit tests

normal, replace the K20 ECM.

5. Test for 2.6-4.6 V between the control circuit terminal 2 and ground.

瀚慖f the voltage is not within the specified range, replace the K20 ECM.

6. If all circuits test normal, test or replace the Q40 turbocharger bypass solenoid valve.

Component Testing

1. Ignition OFF, disconnect the harness connector at the Q40 turbocharger bypass solenoid valve.

2. Test for 12-60 ohm between the control terminal 2 and the ignition terminal 1 of the Q40 turbocharger bypass solenoid valve.

瀚慖f not within the specified range, replace the Q40 turbocharger bypass solenoid valve.

3. Test for infinite resistance between each terminal and the Q40 turbocharger bypass solenoid valve housing.

瀚慖f not the specified value, replace the Q40 turbocharger bypass solenoid valve.

Repair Instructions

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

* Turbocharger Disassemble (See: Engine, Cooling and Exhaust/Engine/Service and Repair/Overhaul/101. Turbocharger Disassemble)

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

programming

P0034

DTC P0033-P0035

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 P0033

- Turbocharger Bypass Solenoid Valve Control Circuit

DTC P0034

- Turbocharger Bypass Solenoid Valve Control Circuit Low Voltage

DTC P0035

- Turbocharger Bypass Solenoid Valve Control Circuit High Voltage

Diagnostic Fault Information