P1EAC
DTC P1EAC
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 P1EAC
- Hybrid/EV Battery Cell Overvoltage Signal/Circuit Performance
Circuit/System Description
The 2nd protection is a redundant method to monitor cell group overvoltage. The battery energy control modules independently reads and tests each cell group and communicates this to the hybrid powertrain control module. The hybrid powertrain control module diagnoses this message to determine when a cell group overvoltage condition exists.
The battery energy control module diagnoses the function of the redundant monitor, once, every power down cycle. When run/crank input signal transitions low and after a calibrated delay, the battery energy control module informs the hybrid powertrain control module, via serial data, that it is about to run the diagnostics on the 2nd protection circuit. The battery energy control module then proceeds to run the check on the serial data cell overvoltage true or false message. If any pulses are missing from the serial data message, the starter/generator control module will report this as a fault.
Conditions for Running the DTC
* Ignition mode transitions from RUN or CRANK to OFF
* 2nd protection fault test bit is active
* No faults are set that would cause the contactors to become open when propulsion is active
* DTC U182A is not set
Conditions for Setting the DTC
The test active bit is active for 12 seconds
OR
The test active bit does not transition to active
OR
The enumerated results does not match the expected result or not enough "True" responses are received
Action Taken When the DTC Sets
* DTC P1EAC is a type A DTC
* The vehicle operates in a low battery mode with the high voltage contactors closed, but no hybrid functions will occur
Conditions for Clearing the DTC
DTC P1EAC is a type A DTC
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 Verification
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. Verify no communication DTCs are set in the K16 battery energy control module or K59 starter/generator control module.
• If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Verify DTC P1A5E or P1A5F are not set.
• If the DTC is set, refer to DTC P1A5E or P1A5F P1A5E.
3. Verify DTC P1A60 is not set.
• If the DTC is set, refer to DTC P1A60 P1A60.
4. Verify DTC P1EAC is not set.
• If the DTC is 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