2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1243

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1243

The drive motor generator power inverter control module (PIM) contains two motor control modules (MCMs). Each MCM operates its respective

drive motor generator based upon hybrid powertrain control module (HPCM) commands. Each MCM controls the speed, direction and output

torque of its respective drive motor generator through the sequencing actuation of high current switching transistors called insulated gate bipolar

transistors (IGBTs). Each IGBT assembly is monitored for fault conditions.

Conditions for Running the DTC

* The high voltage contactor relays are closed.

* Ignition voltage is 8-18 volts.

Conditions for Setting the DTC

The MCM detects excessive current flow through the switched portion of the IGBT.

Action Taken When the DTC Sets

* DTCs P0A78 and P0A79 are Type A DTCs.

* The PIM commands the battery energy control module (BECM) to open the high voltage contactor relays.

Conditions for Clearing the DTC

DTCs P0A78 and P0A79 are Type A DTCs.

Reference Information

Schematic Reference

Hybrid Controls Schematics ()

Connector End View Reference

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

DTC Type Reference

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

(DTC) Type Definitions)

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)

Circuit/System Verification

1. Clear the DTC information.

2. Turn the ignition OFF for 2 minutes.

3. Turn the ignition ON.

4. Operate the vehicle within the conditions for running and setting.

5. Retest for the DTC.

Circuit/System Testing

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection.

Personal Protection Equipment (PPE) and proper procedures must be followed.

The High Voltage Disabling procedure will perform the following tasks:

* Identify how to disable high voltage.

* Identify how to test for the presence of high voltage.

* Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures

must be followed.

Failure to follow the procedures exactly as written may result in serious injury or death.