GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0C32: Hybrid Battery Pack Cooling System Performance

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Air Inlet Sensor Signal

P0AAE

P0AAF

P0AAF

--

Air Inlet Sensor Low Reference

--

P0AAF

--

--

Air Outlet Sensor Signal

P0AB3

P0AB4

P0AB4

--

Air Outlet Sensor Low Reference

--

P0AB4

--

--

Temperature Sensor 1 Signal

P0A9D

P0A9E

P0A9E

--

Temperature Sensor 1 Low Reference

--

P0A9E

--

--

Temperature Sensor 2 Signal

P0AC7

P0AC8

P0AC8

--

Temperature Sensor 2 Low Reference

--

P0AC8

--

--

Temperature Sensor 3 Signal

P0ACC

P0ACD

P0ACD

--

Temperature Sensor 3 Low Reference

--

P0ACD

--

--

Temperature Sensor 4 Signal

P0AEA

P0AEB

P0AEB

--

Temperature Sensor 4 Low Reference

--

P0AEB

--

--

Typical Scan Tool Data

Hybrid Batt. Inlet Air Temperature

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON

Parameter Normal Range: 26°C (79°F)

Hybrid Battery Inlet Air Temperature Signal

100°C (212°F)

-40°C (-40°F)

--


Hybrid Batt. Inlet Air Temperature Sensor

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON

Parameter Normal Range: 3.2 Volts

Hybrid Batt Inlet Air Temperature Signal

0 Volts

4.75 Volts

5 Volts


Hybrid Batt. Mod. 1-4 Temperature

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON

Parameter Normal Range: 26°C (79°F)

Temperature Sensor 1-4 Signal

100°C (212°F)

-40°C (-40°F)

--

Circuit/System Description

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 V 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 drive motor generator battery control module (GBCM) uses these temperature sensors to determine the hybrid battery temperature and to control the battery vent fan operation.

Conditions for Running the DTC

    • The ignition is ON.
    • The 12 V battery voltage is 9-18 V.
    • The drive motor generator battery vent fan is ON.

Conditions for Setting the DTC

    • DTCs P0AAE and P0AAF are not set.
    • Drive motor generator battery air inlet temperature is less than 38°C ( 100°F) and the GBCM detects the max battery temperature is more than 58°C (136°F) for 120 seconds.

Action Taken When the DTC Sets

DTC P0C32 is a type B DTC.

Conditions for Clearing the DTC

DTC P0C32 is a type B DTC.

Diagnostic Aids

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.

Reference Information

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

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

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

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.

    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.
  3. If the DTC does not set, review the customers driving conditions, refer to Diagnostic Aids.
  4. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling.
  5. Remove the drive motor generator battery upper cover. Refer to Drive Motor Battery Case Upper Cover, Front Cover, and Right Side Cover Replacement.
  6. Verify that there is no cooling fan inlet duct or outlet duct obstruction.
  7. If obstructed, remove or repair as needed for proper air flow.
  8. Check the battery vent fan for any damage to the battery vent fan blades.
  9. If the battery vent fan or cooling fan blades are damaged, replace the generator battery vent fan.
  10. Unclip and remove hybrid battery temperature sensors and allow them to stand at room air temperature for approximately 3 minutes.
  11. Ignition ON, observe the hybrid battery air temperature parameters with a scan tool. The temperatures should be approximately the same value.
  12. 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.
  13. Ignition OFF, disconnect the X3 connector at the GBCM.
  14. Test the resistance across each temperature sensor signal and low reference circuits. Refer to Temperature Versus Resistance. All sensors should measure within 500 Ω of each other.
  15. 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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    •  Generator Battery Vent Fan Replacement
    •  Drive Motor Battery Sensor Module Wiring Harness Replacement
    •  Control Module References for drive motor generator battery control module replacement, setup and programming.