2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1113
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B52 HO2S 2.
2. Ignition ON, verify that the scan tool HO2S 2 voltage parameter is between 350-500 mV.
瀚慖f less than the specified range, test the signal circuit terminal 4 for a short to ground. If the circuit/connections test normal, replace the
K20 ECM.
瀚慖f greater than the specified range, test the signal circuit terminal 4 for a short to voltage. If the circuit/connections test normal, replace the
K20 ECM.
3. Connect a 3 A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool HO2S voltage parameter is less than
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
K20 ECM.
4. Connect a 3 A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 3. Verify the scan tool HO2S 2
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 K20 ECM.
5. Verify that the following conditions do not exist:
* Lean, rich, or leaking fuel injectors-Refer to Fuel Injector Solenoid Coil Test (LAU) (See: Powertrain Management/Fuel Delivery and
Air Induction/Fuel Injector/Testing and Inspection/Fuel Injector Solenoid Coil Test)Fuel Injector Solenoid Coil Test (LF1, LFW) (See:
Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and Inspection/Fuel Injector Solenoid Coil Test).
* A fuel pressure that is too low or too high-Refer to Fuel System Diagnosis (LF1 China) (See: Powertrain Management/Fuel Delivery
and Air Induction/Fuel Pump/Testing and Inspection/Fuel System Diagnosis (China))Fuel System Diagnosis (LF1 Except China) (See:
Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Testing and Inspection/Fuel System Diagnosis (Except China))Fuel
System Diagnosis (LAU China) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Testing and Inspection/Fuel
System Diagnosis (China))Fuel System Diagnosis (LAU Except China) (See: Powertrain Management/Fuel Delivery and Air
Induction/Fuel Pump/Testing and Inspection/Fuel System Diagnosis (Except China)).
* Fuel that is contaminated-Refer to 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))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 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
P0141
DTC P0135 or P0141 (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.
