2010 Cadillac CTS Sedan AWD V6-3.6L Page 1106

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1106

60 mV.

瀚慖f greater than the specified range, test the signal circuit for an open/high resistance. If the circuit/connections test normal, replace the

ECM.

4. Connect a 3 A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool HO2S

voltage parameter is less than 60 mV.

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

circuit/connections test normal, replace the ECM.

5. Verify that the following conditions do not exist:

* Lean, rich, or leaking fuel injectors.

* A fuel pressure that is too low or too high-Refer to Fuel System Diagnosis (See: Powertrain Management/Computers and Control

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

* Fuel that is contaminated-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)).

* Evidence of water intrusion into the electrical connector of the HO2S

* The HO2S is loose

* Exhaust leaks near the HO2S

* Engine vacuum leaks

瀚慖f you find any of the above conditions, repair as necessary.

6. If all circuits/connections test normal, replace the appropriate 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 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

P0158

DTC P0137, P0138, P0140, P0157, P0158, or P0160 (With 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 P0137

- HO2S Circuit Low Voltage Bank 1 Sensor 2

DTC P0138

- HO2S Circuit High Voltage Bank 1 Sensor 2

DTC P0140

- HO2S Circuit Insufficient Activity Bank 1 Sensor 2

DTC P0157

- HO2S Circuit Low Voltage Bank 2 Sensor 2