2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2806

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2806

* Electrical Center Identification Views (See: Maintenance/Fuses and Circuit Breakers/Fuse/Application and ID)

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.

Note: On the scan tool, the powertrain relay is referred to as the EC ignition relay.

3. Ignition ON, observe the scan tool DTC information. Verify DTC P0685 or P0690 is not set.

瀚慖f a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble

Code (DTC) List - Vehicle) for further diagnosis.

4. Ignition ON, engine OFF, observe the scan tool Ignition 1 Voltage signal and the EC Ignition Relay Feedback signal parameters. There

should be no greater than 3 V difference between the 2 parameters.

5. 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: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

Note:

* The ignition 1 signal is supplied by the Run/Crank relay. The EC ignition relay feedback signal is supplied by the powertrain relay.

* High resistance in the ignition 1 signal or EC ignition relay feedback circuit/underhood fuse block will cause the DTC to set.

1. Ignition OFF, disconnect the KR75 powertrain relay.

2. Verify a test lamp illuminates between both of the following relay battery voltage circuit terminals and ground:

* Terminal 85

* Terminal 30

瀚慖f the test lamp does not illuminate, test the relay battery voltage circuit for an open/high resistance or a short to ground.

3. Ignition OFF, verify that a test lamp does not illuminate between the ignition voltage circuit terminal 87 and ground.

瀚慖f the test lamp illuminates, test the ignition voltage circuit for a short to voltage.

4. Connect a 20 A fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch ignition voltage circuit terminal 87.

5. Ignition ON, observe the scan tool EC Ignition Relay Feedback Signal parameter. The ECM should communicate, and the parameter should

display B+.

瀚慖f not the specified value, or the ECM does not communicate, test the ignition voltage circuit between the powertrain relay and the ECM

for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.

6. Ignition OFF, verify that a test lamp does not illuminate between the control circuit terminal 86 and B+.

瀚慖f the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

7. Connect a DMM set to the diode setting between the control circuit terminal 86 and ground.

8. Ignition ON, verify the DMM does not display OL.

瀚慖f the DMM displays OL, test the control circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the K20

ECM.

9. If all circuits test normal, replace the KR75 powertrain relay.