2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2886

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2886

2. Ignition OFF, disconnect the harness connector at the appropriate HO2S.

3. Test for less than 5 ohm between the low reference circuit terminal A and ground.

瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

4. Ignition ON, verify the appropriate scan tool HO2S parameter is approximately 450 mV.

瀚慖f less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.

瀚慖f greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool HO2S 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 circuits test normal, replace the ECM.

6. Verify none of the following conditions exist:

* Lean fuel injectors-Refer to Fuel Injector Diagnosis (CH47976) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel

Injector/Testing and Inspection)Fuel Injector Diagnosis (J39021 or Scan Tool) (See: Powertrain Management/Fuel Delivery and Air

Induction/Fuel Injector/Testing and Inspection)

* Water intrusion in the HO2S harness connector

* Low fuel system pressure-Refer to Fuel System Diagnosis (w/o FPCM) (See: Powertrain Management/Computers and Control

Systems/Testing and Inspection/Component Tests and General Diagnostics)Fuel System Diagnosis (FPCM) (See: Powertrain

Management/Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics)

* Fuel that is contaminated-Refer to 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))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))

* Exhaust leaks near the HO2S

* Engine vacuum leaks

* Contaminated HO2S - Silicon

* An engine mechanical condition- Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and

Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical)

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

7. If all circuits test normal, replace the appropriate HO2S.

Repair Instructions

Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution (See: Powertrain Management/Computers and Control

Systems/Oxygen Sensor/Service Precautions/Heated Oxygen Sensor Resistance Learn Reset Caution).

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

* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (1500 Series) (See: Powertrain Management/Computers and Control

Systems/Oxygen Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (2500 Series) (See: Powertrain

Management/Computers and Control Systems/Oxygen Sensor/Service and Repair)

* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (1500 Series) (See: Powertrain Management/Computers and Control

Systems/Oxygen Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (2500 Series) (See: Powertrain

Management/Computers and Control Systems/Oxygen Sensor/Service and Repair)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

P2273

DTC P2271 or P2273

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.