P0AC2
DTC P0AC1, P0AC2, P1A07, or P1EBA
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 Descriptor
DTC P0AC1
- Hybrid Battery Current Sensor Circuit Low Voltage
DTC P0AC2
- Hybrid Battery Current Sensor Circuit High Voltage
DTC P1A07
- Battery Energy Control Module 5 Volt Reference Circuit
DTC P1EBA
- Hybrid Battery Current Sensor Performance
Circuit/System Description
The battery energy control module uses a single battery current sensor to determine the current flow out of the hybrid battery pack. The battery energy control module applies 5 volt and provides a low reference to power the sensor. Current measurement is communicated to the battery energy control module via a signal circuit.
Conditions for Running the DTC
P0AC1, P0AC2
* 12 V battery voltage is greater than 8.8 V
* Battery energy control module is awake and communicating
* DTC P1A07 is not set.
P1A07
* 12 V battery voltage is greater than 8.8 V
* Battery energy control module is awake and communicating
P1EBA
* 12 V battery voltage is greater than 8.8 V
* Battery energy control module is awake and communicating
* Contactors are open
* DTC P1A07 is not set.
Conditions for Setting the DTC
P0AC1
Current sensor signal voltage is less than the minimum expected signal voltage
P0AC2
Current sensor signal voltage is greater than the maximum expected signal voltage
P1A07
* Current sensor 5 volt reference voltage is greater than 5.2 V
* Current sensor 5 volt reference voltage is less than 4.8 V
P1EBA
* Current sensor value is more than 2.43 V greater than sensor offset upper limit
* Current sensor value is more than 2.57 V less than sensor offset lower limit
Action Taken When the DTC Sets
DTC P0AC1, P0AC2, P1A07, and P1EBA are type B DTCs
Conditions for Clearing the DTC
DTC P0AC1, P0AC2, P1A07, and P1EBA are type B DTCs
Reference Information
Schematic Reference
Hybrid Energy Storage Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Drive Motor Battery System Description Drive Motor Battery System Description
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 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.
1. Ignition OFF, disable high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling High Voltage Disabling.
2. Disconnect the harness connector at the B30 hybrid/EV battery pack current sensor.
3. Connect the 12 V battery.
4. Ignition OFF, test for less than 30 ohm between the low reference circuit terminal B and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K16 battery energy control module.
5. Ignition ON, test for 4.8-5.2 V between the 5V reference circuit terminal C and ground.
• If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the K16 battery energy control module.
• If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K16 battery energy control module.
6. Ignition OFF, disconnect the X1 harness connector at the K16 battery energy control module.
7. Ignition ON, test for less than 1 V between the signal circuit terminal 2 X1 and ground.
• If greater than the specified range, test the signal circuit for a short to voltage.
8. Ignition OFF, test for infinite resistance between the signal circuit terminal 2 X1 and ground.
• If not the specified value, test the signal circuit for a short to ground.
9. Test for less than 2 ohm between the signal circuit terminal 2 at the battery energy control module harness connector X1 and the signal circuit terminal A at the battery current sensor harness connector.
• If greater than the specified range, test the signal circuit for an open/high resistance.
10. If all circuit test normal, replace the B30 hybrid/EV battery pack current sensor.
11. Verify that DTC P0AC1, P0AC2, P1A07, or P1EBA is not set.
• If any of the DTCs are set, replace the K16 battery energy control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
Control Module References Control Module References for battery energy control module replacement, programming, and setup