2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1108

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1108

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 B52 HO2S 2 sensor.

Repair Instructions

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

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

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

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

programming

P0138

DTC P0137, P0138, or P0140 (Without LF1)

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 Sensor 2

DTC P0138

- HO2S Circuit High Voltage Sensor 2

DTC P0140

- HO2S Circuit Insufficient Activity Sensor 2

Diagnostic Fault Information

Typical Scan Tool Data

Circuit Description

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding

air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the