P1A0D

DTC P1A0C or P1A0D

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P1A0C
- Battery Energy Control Module System Voltage Low

DTC P1A0D
- Battery Energy Control Module System Voltage High

Typical Scan Tool Data










Circuit/System Description

The battery energy control module (BECM) continuously monitors the system voltage on the ignition 1 voltage circuits. Lower than normal voltage may be inadequate for operation of the energy storage components. Improper operation may cause erratic hybrid drive motor battery operation that could include a no start condition.

Conditions for Running the DTC

The vehicle power mode is RUN.

Conditions for Setting the DTC

P1A0C

The BECM detects ignition voltage is less than 9 volts for 3 seconds.

P1A0D

Ignition voltage has been greater than 18 volts for 3 seconds.

Action Taken When the DTC Sets

DTCs P1A0C and P1A0D are Type C DTCs.

Conditions for Clearing the DTC

DTCs P1A0C and P1A0D are Type C DTCs.

Diagnostic Aids

Observe the driver information center (DIC) messaging that would indicate the electrical system requires service.

Inspect for the following conditions:

* Loose or poor connections at the hybrid drive motor battery X350 18-way connector.
* Verify that DTC P0A8D or P0A8E are not set.
* Verify that the 12 volt battery and charging system is within normal operating range.

Special Tools

EL-48900 HEV Safety Kit

Circuit/System Verification

1. Ignition ON, with a scan tool, monitor the control module voltage parameter in the BECM data display list. The control module voltage should be between 12-15 volts.
2. Operate the vehicle within the Conditions for Running the DTCs. You may also operate the vehicle within the conditions that you observed from the Freeze Fame/Failure Records data.

Circuit/System Testing

1. Verify that DTC P0A8D or DTC P0A8E are not set.

^ If any of the listed DTCs are set, repair them first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle. Diagnostic Trouble Code Descriptions

2. Ignition ON, with a scan tool, monitor the control module voltage parameter in the BECM data display list. The voltage parameter should display between 12.0-15.0 volts.

^ If the voltage is less than the specified value, test the ignition voltage circuit for an open/high resistance connection, If all circuits test normal replace the drive motor generator battery control module.
^ If the voltage is more than the specified value, Replace the drive motor generator battery control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair. Verification Tests