2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2888

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2888

Conditions for Clearing the DTC

DTCs P2271 or P2273 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description ( See: Hybrid Drive

Systems/Description and Operation/Hybrid Modes of Operation).

2. Ignition ON, verify the scan tool hood position parameter displays Open.

瀚慖f the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) for DTC P254F.

3. Ignition ON, observe the DTC information with a scan tool. Verify that no HO2S heater DTCs are set.

瀚慖f any HO2S heater DTCs are set, perform those diagnostics first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (See:

Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).

4. Engine idling, move the appropriate HO2S 2 harness connector and the engine control module (ECM) harness connector while monitoring

the HO2S 2 voltage parameter with a scan tool. Verify that the HO2S parameter does not change abruptly while moving the related

harnesses.

瀚慖f the HO2S parameter does change abruptly while moving the related harnesses repair the circuit as necessary.

5. Engine idling at operating temperature, observe the appropriate HO2S 2 parameter with a scan tool. The HO2S 2 value should change greater

than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM

for 30 seconds.

6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the scan tool and wait 60 seconds to ensure all modules are powered down.

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.