Circuit/System Testing

Verify that DTCs P0A81, P0A9C, P0A9D, P0A9E, P0AC6, P0AC7, P0AC8, P0ACB, P0ACC, P0ACD, P0AE9, P0AEA, and P0AEB are not set.

• If any of the listed DTCs are set, repair them first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

WARNING: Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:
• Safety glasses with appropriate side shields when within 50 feet of the vehicle, either indoors or outdoors
• Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors
  • Visually and functionally inspect the gloves before use.
  • Wear the Insulation gloves at all times when working with the high voltage battery assembly, whether the system is energized or not.

Failure to follow the procedure exactly as written may result in serious injury or death.
1. Ignition ON, command the hybrid battery vent fan ON using a scan tool. Verify the battery vent fan is functional in all speed ranges.
2. Observe all four hybrid battery module temperature sensor parameters for 60 seconds using a scan tool. Verify that hybrid battery temperature parameters are within the conditions for setting.
   • If the DTC does not set, review the customers driving conditions, refer to Diagnostic Aids.
3. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling .
4. Remove the drive motor generator battery upper cover. Refer to Drive Motor Battery Case Upper Cover, Front Cover, and Right Side Cover Replacement .
5. Verify that there is no cooling fan inlet duct or outlet duct obstruction.
   • If obstructed, remove or repair as needed for proper air flow.
6. Check the battery vent fan for any damage to the battery vent fan blades.
   • If the battery vent fan or cooling fan blades are damaged, replace the generator battery vent fan.
7. Unclip and remove hybrid battery temperature sensors and allow them to stand at room air temperature for approximately 3 minutes.
8. Ignition ON, observe the hybrid battery air temperature parameters with a scan tool. The temperatures should be approximately the same value.
   • If the temperature sensor parameters are not approximately the same value, continue to next step.
   • If the temperature sensor parameters are approximately the same value, the hybrid batteries should be allowed to cool down by letting the vehicle stand at room temperature. This could take up to 8 hours. Inspect the internal foam seals for damage or if missing and repair as needed. Check for proper cooling fan operation and air flow.
9. Ignition OFF, disconnect the X3 connector at the BECM.
10. Test the resistance across each temperature sensor 5-volt reference and low reference circuits. Refer to Temperature Versus Resistance . All sensors should measure within 500 ohms of each other.
    • If greater than the specified value, replace the drive motor battery sensor module wiring harness.
    • If less than the specified value, replace the drive motor generator battery control module and re-install the temperature sensors. Refer to Generator Battery Temperature Sensor Location  for the proper locations.