Circuit/System Testing

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

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

1. With a scan tool, monitor all four hybrid battery module temperature sensors for 60 seconds. Verify that hybrid battery temperature parameters are within the conditions for setting.
   • If the hybrid battery temperature parameters are not within the conditions for setting, try to duplicate the customer driving conditions, refer to Diagnostic Aids.
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.
2. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling .
3. Remove the drive motor generator battery upper cover. Refer to Drive Motor Battery Case Upper Cover, Front Cover, and Right Side Cover Replacement .
4. Verify that there is no cooling fan inlet duct or outlet duct obstruction.
   • If obstructed, remove or repair as needed for proper air flow.
5. Inspect the vent fan for any damage to the fan blades.
   • If fan or blades are damaged replace the battery vent fan.
6. Unclip and remove all four hybrid battery temperature sensors from the batteries and allow them to stand at room air temperature for approximately 3 minutes.
7. Ignition ON, with a scan tool monitor the temperature parameters for all four temperature sensors, the temperatures should all be approximately the same value.
   • If all four temperature sensors are not approximately the same value, continue to next step.
   • If all four temperature sensors are approximately the same value, allow the hybrid batteries to cool down by letting the vehicle stand at room temperature, This could take 4 to 8 hours. Inspect the internal foam seals for damage or if missing and repair as needed. Inspect for proper cooling fan operation and air flow.
8. Ignition OFF, disconnect the X3 connector at the BECM.
9. 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 500 ohms, replace the drive motor battery sensor module wiring harness assembly.
   • If less than 500 ohms, replace the drive motor generator battery control module and re-install the four temperature sensors. Refer to Generator Battery Temperature Sensor Location  for the proper locations.