DTC P1A0C or P1A0D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P1A0C
- Battery Energy Control Module System Voltage Low
DTC P1A0D
- Battery Energy Control Module System Voltage High
Circuit/System Description
The drive motor generator battery control module is also referred to as the battery energy control module (BECM). The drive motor generator
battery control module will diagnose its own systems and determine when a fault condition is present. Diagnostics and system status is
communicated from the drive motor generator battery control module to the hybrid powertrain control module (HPCM) through serial data. The
hybrid powertrain control module is the host controller for diagnostic trouble code (DTC) information. The drive motor generator battery control
module continuously monitors the system voltage on the ignition 1 voltage circuit.
Conditions for Running the DTC
* The vehicle power mode is RUN.
* DTC P0A1F is not set.
Conditions for Setting the DTC
P1A0C
The drive motor generator battery control module detects the ignition voltage is less than 9 V for 3 seconds.
P1A0D
The drive motor generator battery control module detects the ignition voltage is greater than 16 V for 3 seconds.
Action Taken When the DTC Sets
P1A0C
* DTCs P1A0C and P1A0D are Type C DTCs.
* The drive motor generator battery control module commands the battery vent fan to High.
P1A0D
* DTCs P1A0C and P1A0D are Type C DTCs.
* The drive motor generator battery control module commands the battery vent fan to High.
* After 8 minutes of ignition voltage over 16 V, the high voltage contactor coils will become hot and the drive motor generator battery control
module will open the contactors. The drive motor generator battery control module will not close the high voltage contactors for 30 minutes
to allow high voltage contactors to cool.
Conditions for Clearing the DTC
* DTCs P1A0C and P1A0D are Type C DTCs.
* The control module ignition voltage is between 9-16 V.
Diagnostic Aids
Observe the driver information center (DIC) messaging that would indicate the charging system requires service.
Inspect for the following conditions:
* Loose or poor connections at the hybrid drive motor battery X350 18-way connector.
* Loose or poor connections at the 12 V negative battery cable G102.
* Verify that the 12 V battery and charging system is within normal operating range and if a battery charger was connected to the vehicle.
