2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1172

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1172

Circuit/System Description

The accessory power module (APM) monitors its 14-volt circuit when it is enabled for charge or Jump Assist. It requires a minimum voltage on this

circuit in order to begin operation. This DTC sets when the 14-volt circuit in the APM is below this minimum level at the time it is enabled. APM

functions will run only when an APM enable message from the hybrid powertrain control module (HPCM) is active on the high speed hybrid

GMLAN communication circuit.

Conditions for Running the DTC

APM commanded to begin charging or Jump Assist.

Conditions for Setting the DTC

14-volt circuit at the APM is below 6.7 volts when attempting to begin charging or Jump Assist.

Action Taken When the DTC Sets

* DTC P0AFF is a Type C DTC.

* The APM will not allow 14-volt or 42-volt conversions to begin in this condition.

Conditions for Clearing the DTC

* DTC P0AFF is a Type C DTC.

* The 14-volt circuit at the APM is above 6.7 volts.

Diagnostic Aids

The APM is protected from reverse polarity connections by a 200-amp in-line mega-fuse. The output current of the APM is lower than the fuse

rating.

Reference Information

Schematic Reference

Hybrid Controls Schematics ()

Connector End View Reference

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

Description and Operation

Drive Motor Generator Control Module Description and Operation ()

Electrical Information Reference

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

Testing/Circuit Testing)

* 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)

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 Testing

1. Remove the B+ harness connector X3 at the APM.

2. Connect a test lamp between the 12-volt battery positive and the APM connector X3 at the module.

3. Ignition ON, observe the 12-volt parameter in the APM data list. The parameter should be within 0.5 volt of the actual 12-volt battery

voltage.

瀚慖f the voltage is not within the specified range, replace the APM.