The drive motor generator battery control module is also referred to as the battery energy control module (BECM). The BECM will diagnose its own systems and determine when a fault condition is present. Diagnostics and system status is communicated from the BECM to the hybrid powertrain control module (HPCM) through the Hybrid LAN communication circuit. The HPCM is the host controller for diagnostic trouble code (DTC) information.

The drive motor generator battery has four hybrid battery temperature sensors, an air inlet temperature sensor and an air outlet temperature sensor. The air inlet temperature sensor is referred to as sensor 1 and the air outlet temperature sensor is referred to as sensor 2. The hybrid battery temperature sensors are located on the top of the hybrid batteries. Both the hybrid battery temperature sensors and the air inlet and outlet sensors are a variable resistor that measures the temperature. The control module supplies 5-volts to the signal circuit and a ground for the low reference circuit. The temperature sensor resistance changes with temperature. The lower the temperature, the higher the sensor resistance. The higher the temperature, the lower the sensor resistance. The BECM uses these temperature sensors to determine the hybrid battery temperature and to control the battery vent fan operation.

DTC P0C32 is a Type B DTC.

DTC P0C32 is a Type B DTC.

Battery temperatures can be affected by vehicle load, outside temperature, and customer driving conditions. Test drive the vehicle to simulate the conditions this DTC set under.

Schematic Reference

Hybrid Energy Storage Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL-48900 HEV Safety Kit

1. Clear the DTC information.
2. Turn the ignition OFF for 3 minutes.
3. Turn the ignition ON.
4. Retest for DTC P0C32.
5. Operate the vehicle within the conditions for running the DTCs. You may also operate the vehicle within the conditions that you observed from the freeze fame/failure records data.

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

Danger: 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.

Perform the Diagnostic Repair Verification after completing the repair.