2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1248

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1248

DTC Descriptors

DTC P0A81

- Hybrid Battery Pack Cooling Fan Control Circuit

DTC P0BC1

- Hybrid Battery Pack Cooling Fan Positive Voltage Control Circuit High Voltage

Diagnostic Fault Information

Circuit/System Description

The drive motor generator battery is cooled by a drive motor battery vent fan motor. The battery vent fan motor and battery vent fan relay are

located inside the drive motor generator battery assembly. B+ to the battery vent fan is provided from the battery vent fan relay when the drive

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 ()