2010 Cadillac CTS Sedan AWD V6-3.6L Page 926

2010 Cadillac CTS Sedan AWD V6-3.6L Page 926

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

P0038

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

DTC P0036

- Heater Control Circuit Bank 1 Sensor 2