P1A1F
DTC P1A1F or P1A4E
Diagnostic Instructions
* 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 Descriptors
DTC P1A1F
- Battery Energy Control Module Hybrid Battery System Voltage Low
DTC P1A4E
- Battery Energy Control Module Hybrid Battery 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 monitors the calculated battery voltage and the terminal voltage. The calculated voltage represents the sum of the voltages from the 20 individual battery measurements. The terminal voltage represents the total DC bus voltage as measured on the output side of the high voltage contactors.
Conditions for Running the DTC
* The vehicle power mode is RUN.
* Ignition voltage is 9-18 V.
Conditions for Setting the DTC
P1A1F
The calculated battery voltage measurement is less than 168 V for 4 seconds
OR
Individual hybrid battery voltage measurement is less than 8.4 V for 4 seconds.
P1A4E
The calculated battery voltage measurement is greater than 408 V for 4 seconds
OR
Individual hybrid battery voltage measurement is greater than 20.4 V for 4 seconds.
Action Taken When the DTC Sets
DTCs P1A1F and P1A4E are Type C DTCs.
Conditions for Clearing the DTC
P1A1F
* DTCs P1A1F is a Type C DTC.
* The calculated battery voltage measurement is greater than 260 V.
* Each individual hybrid battery voltage measurement is greater than 13 V.
P1A4E
* DTCs P1A4E is a Type C DTC.
* The calculated battery voltage measurement is less than 390 V.
* Each individual hybrid battery voltage measurement is less than 19.5 V.
Reference Information
Schematic Reference
Hybrid Energy Storage Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
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)
DTC Type Reference
Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
* EL-48571 High Voltage Battery Pin Out Box
* 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, P0B89, P0B8C, P0B8D, P0B8E, P0B91, P0B92, P0B93, P0B96, P0B97, P0B98, P0B9B, P0B9C, P0B9D, or P0ABB is not set.
• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).
2. Ignition ON, engine OFF, verify the scan tool Hybrid Battery Pack Calculated Voltage parameter is 230-407 V.
3. Observe the scan tool Hybrid Battery 1-20 parameters. Each reading should be between 10-19 V and all readings should be within 1.5 V of each other.
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 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 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.
1. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling (High Voltage Disabling).
2. Test for 230-407 V between the high voltage positive terminal X2 at the high voltage positive contactor and the high voltage negative terminal X2 at the high voltage negative contactor.
• If the voltage is less than 194 V, replace the drive motor generator battery.
• If the voltage is between 194-230 V, perform the jump assist. Refer to Jump Assist (Hybrid Energy Storage).
• If the voltage is greater than 407 V, replace the drive motor generator battery control module.
3. Disconnect the X4 harness connector at the drive motor generator battery control module.
4. Connect the EL-48571 high voltage battery pin out box.
5. Install the high voltage manual disconnect lever. Measure and record each of the 20 battery voltages.
6. Each battery voltage reading should be between 10-19 V.
• If not within the specified range, replace the drive motor battery assembly.
7. Each battery voltage reading should be within 1.5 V of each other.
• If not within the specified range, replace the drive motor battery assembly.
8. If all circuits test normal, replace the drive motor generator battery control module.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
* Drive Motor Generator Battery Replacement and Shipping Preparation (Drive Motor Generator Battery Replacement and Shipping Preparation)
* Control Module References (Programming and Relearning) for drive motor generator battery control module replacement, setup and programming