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 (GBCM) supplies a ground to the battery vent fan relay. A grounding 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 GBCM. The GBCM uses a pulse width modulated (PWM) signal on the 5 V circuit to control the battery vent fan motor duty cycle. The battery vent fan motor also supplies an additional 5 V signal that indicates vent fan speed back to the GBCM, the lower the voltage the greater the fan speed. The GBCM uses 4 battery temperature sensors, one air inlet duct and one air outlet temperature sensor to control battery vent fan motor operation and speed.

Fan control signal monitor voltage to GBCM is greater than 2.3 V or less than 0.5 V for 5 seconds.

DTC P0A81 is a type B DTC.

DTC P0A81 is a type B DTC.

Verify the GBCM fan fuse is not open.

Schematic Reference

Hybrid Cooling Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Drive Motor Generator Battery Cooling Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL-48900 HEV Safety Kit

Ignition ON, command the battery pack vent fan speed to 60 percent duty cycle with a scan tool. The battery pack vent fan should turn ON.

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.
1. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling.
2. Remove the drive motor generator battery case upper cover, front cover, and right side cover.
3. Disconnect the harness connector at the battery vent fan motor.
4. Connect a test lamp between the ignition circuit terminal 2 and ground.
5. Ignition OFF, connect the 12 V battery.
6. Ignition ON, command the battery pack vent fan speed to 60 percent. The test lamp should illuminate after a 5-7 second delay.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

7. Verify a test lamp illuminates between B+ and the ground circuit terminal 3.

⇒	If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

8. Ignition OFF, connect the harness connector at the battery vent fan motor.
9. Disconnect X2 harness connector at the GBCM.
10. Verify a test lamp illuminates between the vent fan relay control circuit terminal 7 and ground.

⇒	If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal, replace the generator battery vent fan relay.

11. Connect a 3 A fused jumper wire between the vent fan motor relay control circuit terminal 7 and ground.
12. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 2 and ground.

⇒	If the voltage is not within the specified range, test the signal circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the generator battery vent fan.

13. If all circuits test normal, replace the drive motor generator battery control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.