P1A5E
DTC P1A5E or P1A5F
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 P1A5E
- Battery Energy Control Module Ignition 1 Switch Circuit Low Voltage
DTC P1A5F
- Battery Energy Control Module Ignition 1 Switch Circuit High Voltage
Circuit/System Description
The RUN/CRANK relay applies ignition voltage to the ignition 1 circuit when the ignition is in the RUN or CRANK position. The ignition 1 circuit supplies ignition voltage to the starter/generator control module. The ignition 1 circuit also continues through the starter/generator control module in a pass-thru manner and continues to the battery energy control module. The battery energy control module also monitors the power mode message which is broadcast via serial data and compares the power mode message to the actual power mode as indicated by voltage on the ignition 1 circuit.
Controlled by the body control module (BCM), the accessory wakeup circuit supplies voltage to the starter/generator control module as a means to wake the control module and initiate serial data communications. Like the ignition 1 circuit, the accessory wakeup circuit continues through the starter/generator control module in a pass-thru manner and continues to the battery energy control module.
Conditions for Running the DTC
* 12 V battery voltage is greater than 8.86 V
* Battery energy control module is awake and communicating
* Serial data indicates the power mode is RUN/CRANK
* DTC U180B is not set
Conditions for Setting the DTC
The power mode message received via serial data does not match the power mode indicated by the status of the ignition 1 circuit.
Action Taken When the DTC Sets
DTC P1A5E and P1A5F are type B DTCs
Conditions for Clearing the DTC
DTC P1A5E and P1A5F 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, disconnect the X3 harness connector at the K59 starter/generator control module.
2. Verify a test lamp does not illuminate between the ignition voltage circuit terminal 10 and ground.
• If the test lamp illuminates, test the ignition circuit for a short to voltage. If the circuit tests normal, refer to Power Mode Mismatch (Push Button) Power Mode Mismatch (Push Button)Power Mode Mismatch (Key) Power Mode Mismatch (Key).
3. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 10 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Power Mode Mismatch (Push Button) Power Mode Mismatch (Push Button)Power Mode Mismatch (Key) Power Mode Mismatch (Key).
4. Ignition OFF, disable high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling High Voltage Disabling.
5. Connect the X3 harness connector at the K59 starter/generator control module. Disconnect the X1 harness connector at the K16 battery energy control module.
6. Connect the 12 V battery.
7. Verify a test lamp does not illuminate between the ignition voltage circuit terminal 9 and ground.
• If the test lamp illuminates, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the K59 starter/generator control module.
8. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 9 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K59 starter/generator control module.
9. 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.
Control Module References Control Module References for battery energy control module or starter/generator control module replacement, programming, and setup