2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1257
motor generator battery control module (BECM) supplies a ground to the battery vent fan relay. A ground wire from the battery vent fan motor
assembly completes the path to case ground. A 5 V circuit is provided from the battery vent fan motor assembly, to the drive motor generator
battery control module. The drive motor generator battery control module uses a pulse width modulated (PWM) signal on the 5 V circuit to control
the battery vent fan motor duty cycle. The drive motor generator battery control module uses 4 battery temperature sensors, one air inlet duct and
one air outlet temperature sensor to control battery vent fan motor operation and speed.
Conditions for Running the DTC
P0A81
* The ignition is ON.
* Battery voltage is 9-18 V.
* The fan speed is commanded 35 percent or greater.
P0BC1
* The ignition is ON.
* Battery voltage is 9-18 V.
* The fan has transitioned from either ON to OFF or from OFF to ON.
Conditions for Setting the DTC
P0A81
Fan control signal monitor voltage to the drive motor generator battery control module is greater than 2.3 V or less than 0.5 V for 5 seconds.
P0BC1
The fan speed control circuit is greater than 0.9 V for 1 second.
Action Taken When the DTC Sets
DTCs P0A81 and P0BC1 are type B DTCs.
Conditions for Clearing the DTC
DTCs P0A81 and P0BC1 are type B DTCs.
Reference Information
Schematic Reference
Hybrid Cooling Schematics ()
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Drive Motor Generator Battery Cooling Description ()
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)
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
Special Tools
EL-48900 HEV Safety Kit
Circuit/System Verification
