P0ACB
DTC P0A9C-P0A9E, P0AC6-P0AC8, P0ACB-P0ACD, P0AE9-P0AEB, P0BC3-P0BC5, or P0C34-P0C36
Diagnostic Instructions
Danger: This diagnostic has NOT been validated on-vehicle. Follow all safety protocol and utilize all appropriate personal protective equipment to ensure your safety. Failure to follow the procedures exactly as written may result in serious injury or death.
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0A9C
- Hybrid/EV Battery Temperature Sensor 1 Performance
DTC P0A9D
- Hybrid/EV Battery Temperature Sensor 1 Circuit Low Voltage
DTC P0A9E
- Hybrid/EV Battery Temperature Sensor 1 Circuit High Voltage
DTC P0AC6
- Hybrid/EV Battery Temperature Sensor 2 Performance
DTC P0AC7
- Hybrid/EV Battery Temperature Sensor 2 Circuit Low Voltage
DTC P0AC8
- Hybrid/EV Battery Temperature Sensor 2 Circuit High Voltage
DTC P0ACB
- Hybrid/EV Battery Temperature Sensor 3 Performance
DTC P0ACC
- Hybrid/EV Battery Temperature Sensor 3 Circuit Low Voltage
DTC P0ACD
- Hybrid/EV Battery Temperature Sensor 3 Circuit High Voltage
DTC P0AE9
- Hybrid/EV Battery Temperature Sensor 4 Performance
DTC P0AEA
- Hybrid/EV Battery Temperature Sensor 4 Circuit Low Voltage
DTC P0AEB
- Hybrid/EV Battery Temperature Sensor 4 Circuit High Voltage
DTC P0BC3
- Hybrid/EV Battery Temperature Sensor 5 Performance
DTC P0BC4
- Hybrid/EV Battery Temperature Sensor 5 Circuit Low Voltage
DTC P0BC5
- Hybrid/EV Battery Temperature Sensor 5 Circuit High Voltage
DTC P0C34
- Hybrid/EV Battery Temperature Sensor 6 Performance
DTC P0C35
- Hybrid/EV Battery Temperature Sensor 6 Circuit Low Voltage
DTC P0C36
- Hybrid/EV Battery Temperature Sensor 6 Circuit High Voltage
Circuit/System Description
Six temperature sensors are used to monitor the battery temperature. The battery temperature sensors are located in the battery sections. Two of the temperature sensors are located on the top of the battery section and the remaining four are located on the bottom of the section. The temperature sensor is a variable resistor that measures the temperature of the battery cell group. The battery energy control module supplies 5 V to the signal circuit and a ground for the low reference circuit. The battery temperature sensor resistance changes with battery temperature. As the temperature decreases, the sensor resistance increases. As the temperature increases, the sensor resistance decreases.
Conditions for Running the DTC
P0A9C, P0AC6, P0ACB, P0AE9, P0BC3, and P0C34
* Starter/generator control module off time is greater than 6 hours
* Starter/generator control module off time is not faulted (starter/generator control module internal clock diagnostic)
* None of the following DTCs are set: P0A9D, P0A9E, P0AC7, P0AC8, P0ACC, P0ACD, P0AEA, P0AEB, P0B45, P0B46, P0B47, P0B48, P0B4F, P0BC4, P0BC5, P0C35, P0C63, or P1A5D
P0A9D, P0A9E, P0AC7, P0AC8, P0ACC, P0ACD, P0AEA, P0AEB, P0BC4, P0BC5, P0C35, and P0C36
* The 12 V battery voltage is greater than 8.8 V
* Battery energy control module is awake and communicating
* DTC P1A5D is not set
Conditions for Setting the DTC
P0A9C, P0AC6, P0ACB, P0AE9, P0BC3, and P0C34
The difference between a single battery temperature sensor and an average of the other battery temperature sensors is greater than 8.6°C (47.5°F)
P0A9D, P0AC7, P0ACC, P0AEA, P0BC4, and P0C35
The hybrid battery temperature sensor is greater than 87°C (188.2°F)
P0A9E, P0AC8, P0ACD, P0AEB, P0BC5, and P0C36
The hybrid battery temperature sensor is less than -39°C (-38.2°F)
Action Taken When the DTC Sets
DTCs P0A9C, P0A9D, P0A9E, P0AC6, P0AC7, P0AC8, P0ACB, P0ACC, P0ACD, P0AE9, P0AEA, P0AEB, P0BC3, P0BC4, P0BC5, P0C34, P0C35, and P0C36 are type B DTCs
Conditions for Clearing the DTC
DTCs P0A9C, P0A9D, P0A9E, P0AC6, P0AC7, P0AC8, P0ACB, P0ACC, P0ACD, P0AE9, P0AEA, P0AEB, P0BC3, P0BC4, P0BC5, P0C34, P0C35, and P0C36 are type B DTCs
Reference Information
Schematic Reference
Hybrid Cooling Schematics Hybrid Cooling Schematics
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Hybrid Cooling System Description and Operation Hybrid Cooling System Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
EL-48900 - HEV Safety Kit
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
Ignition ON, observe the scan tool battery energy control module Battery Temperature parameters. The parameters should all be between -39° and 60°C (-38.2° and 140°F).
Circuit/System Testing
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.
Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:
* Safety glasses with appropriate side shields when within 15 meters (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 with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.
Failure to follow the procedures exactly as written may result in serious injury or death.
Danger: The eAssist battery pack assembly will utilize an exchange program. Please consult the most recent revision of bulletin/PI #PIPXXYYZZ, available in Service Information (SI), for a list of approved eAssist battery pack assembly service procedures. Components that may be removed and serviced without exchanging the complete battery pack assembly are identified in the bulletin/PI. Please contact the GM Technical Assistance Center (1-877-446-8227) if you have any questions.
Note: In High Voltage Disabling High Voltage Disabling , perform the disabling procedure for servicing components within the A4 hybrid/EV battery pack. The C4A hybrid/EV battery section 1 and C4B hybrid/EV battery section 2 will be disconnected as part of the disabling procedure.
1. Ignition OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling High Voltage Disabling
2. Using the scan tool, determine which battery temperature sensor is greater than 87°C (189°F), less than -39°C (-39°F), or differs from the other temperatures by more than 9°C (16°F).
3. Disconnect the X3 and X4 harness connectors at the K16 battery energy control module.
4. Test for 9-13k ohm at 22°C (72°F) between the appropriate temperature sensor signal circuit terminal and the low reference circuit terminal listed below:
* Temperature sensor 1 - Signal circuit terminal 4 X4 and low reference circuit terminal 9 X4
* Temperature sensor 2 - Signal circuit terminal 3 X4 and low reference circuit terminal 8 X4
* Temperature sensor 3 - Signal circuit terminal 2 X3 and low reference circuit terminal 7 X3
* Temperature sensor 4 - Signal circuit terminal 2 X4 and low reference circuit terminal 7 X4
* Temperature sensor 5 - Signal circuit terminal 1 X4 and low reference circuit terminal 6 X4
* Temperature sensor 6 - Signal circuit terminal 4 X3 and low reference circuit terminal 9 X3
• If not within the specified range, test the signal circuit and low reference circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the C4A hybrid/EV battery section 1 and C4B hybrid/EV battery section 2.
5. If all circuits test normal, replace the K16 battery energy control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Generator Battery Replacement Generator Battery Replacement
* Control Module References Control Module References for battery energy control module replacement, programming, and setup