P1A1F
DTC P1A1F or P1A4E
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 P1A1F
- Battery Energy Control Module Hybrid Battery System Voltage Low
DTC P1A4E
- Battery Energy Control Module Hybrid Battery System Voltage High
Typical Scan Tool Data
Circuit/System Description
The battery energy control module (BECM) monitors the voltage values of the hybrid batteries in more than one method. The BECM monitors the calculated battery voltage (sum of the voltages from the 20 individual battery measurements) and the terminal voltage (total bus voltage measured on the output side of the high voltage relay contactors). When the BECM detects that the calculated battery voltage measurement is out of a specified range these DTCs will set.
Conditions for Running the DTC
* The vehicle power mode is RUN.
* Accessory voltage is 9-18 volts.
Conditions for Setting the DTC
P1A1F
When the calculated battery voltage measurement is less than 168 volts for 4 seconds.
P1A4E
When the calculated battery voltage measurement is more than 407 volts for 4 seconds.
Action Taken When the DTC Sets
DTCs P1A1F and P1A4E are Type C DTCs.
Conditions for Clearing the DTC
DTCs P1A1F and P1A4E are Type C DTCs.
P1A1F
When the calculated battery voltage measurement is greater than 260 volts.
P1A4E
When the calculated battery voltage measurement is less than 390 Volts.
Special Tools
* EL-48569 Terminal Covers
* EL-48900 HEV Safety Kit
Circuit/System Verification
1. Verify that DTC P0B3C, P0B3D, P0B3E, P0B41, P0B42, P0B43, P0B46, P0B47, P0B48, P0B4B, P0B4C, P0B4D, P0B50, P0B51, P0B52, P0B55, P0B56, P0B57, P0B5A, P0B5B, P0B5C, P0B5F, P0B60, P0B61, P0B64, P0B65, P0B66, P0B69, P0B6A, P0B6B, P0B6E, P0B6F, P0B70, P0B73, P0B74, P0B75, P0B78, P0B79, P0B7A, P0B7D, P0B7E, P0B7F, P0B82, P0B83, P0B84, P0B87, P0B88, PP0B89, 0B8C, P0B8D, P0B8E, P0B91, P0B92, P0B93, P0B96, P0B97, P0B98, P0B9B, P0B9C, or P0B9D is not set.
^ If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. Diagnostic Trouble Code Descriptions
2. Ignition On, engine OFF, verify 215-407 volts on the hybrid battery pack calculated voltage parameter and the hybrid battery terminal voltage parameter, with a scan tool.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
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.
* Failure to follow the procedures exactly as written may result in serious injury or death.
Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling.
1. Remove the drive motor generator battery case upper cover and right side cover.
2. Connect the 12 battery.
3. Ignition OFF, verify 215-407 volts between terminals HV+ at the HV positive relay and HV- at the HV negative relay.
^ If the voltage is below 194 volts, replace the drive motor generator battery.
^ If the voltage is above 407 volts, replace the drive motor generator control module.
^ If the voltage is between 194-230 volts, perform the jump assist. Refer to Jump Assist.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair. Verification Tests
* Drive Motor Generator Battery Replacement