P1A1F

DTC P1A1F or P1A4E

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 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 drive motor generator control module through serial data. The drive motor generator control module is the host controller for diagnostic trouble code (DTC) information.

The hybrid battery assembly consists of 22 individual battery modules. Each battery module is rated at 12.0 V. The batteries are connected together in a series circuit. The drive motor generator battery control module monitors the hybrid battery voltage on every two batteries for a total of 22 locations, across the battery assembly. The drive motor generator battery control module determines the actual terminal voltage by monitoring the output voltage from the high voltage contactors. The drive motor generator battery control module also multiplies each individual battery voltage measurement by 22, and compares this calculation to the terminal voltage measurement.

The drive motor generator battery control module monitors and compares these voltages using several different methods. The drive motor generator battery control module determines the calculated battery voltage by adding the voltage at the 22 locations together. The normal operating range for each battery module is 10-15 V. The normal operating range for the battery is 198-320 V.

Conditions for Running the DTC

* The vehicle power mode is RUN.
* Accessory voltage is 9-18 V.

Conditions for Setting the DTC

P1A1F
* The hybrid battery pack voltage measurement is less than 198 V for 4 seconds.
* The minimum module measurement is less than 9.0 V for 2 seconds.

P1A4E
* The hybrid battery pack voltage measurement is greater than 375 V for 4 seconds.
* The maximum module measurement is greater than 16.25 V for 40 seconds.

Action Taken When the DTC Sets

* DTCs P1A1F and P1A4E are Type C DTCs.
* The drive motor generator battery control module will request the drive motor generator control module to open the HV contactors.

Conditions for Clearing the DTC

DTC P1A1F and P1A4E are type C DTCs.

Reference Information
Schematic Reference

Hybrid Energy Storage Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Drive Motor Generator Battery Description (Drive Motor Generator Battery Identification Information)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
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, P0BA0,P0BA1, P0BA2, P0BA5, P0BA6, P0BA7, or P0ABB is not set.

• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions).

2. Clear the DTCs.
3. Ignition ON, engine OFF, verify the scan tool Hybrid Battery Pack Calculated Voltage parameter is 198-320 V.
4. 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.

Note: You must perform the Circuit/System Verification first.

1. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling (High Voltage Disabling).
2. Connect the 12 V battery.
3. Ignition ON, engine OFF, verify the scan tool Hybrid Battery Pack Calculated Voltage parameter is 264-320 V.

• If the voltage is between 198-264 V, perform the jump start assist. Refer to Jump Assist (Hybrid Energy Storage - HP5).
• If the voltage is less than 198 V, replace the drive motor generator battery.
• If the voltage is greater than 320 V, replace the drive motor generator control module.

4. Disconnect the X2 harness connector at the drive motor generator battery control module.
5. Connect the EL-48571 to the X2 harness connector.
6. Install the high voltage manual disconnect lever
7. Insert the DMM probes into the EL-48571 test cavities. Measure and record the voltage of each battery by cycling the EL-48571 through each of the 22 switch positions. All voltages should be between 10-15 V and within 1.5 V of each other.

• If any of the voltage values are not within the specified range, replace the drive motor generator 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 (Drive Motor Generator Battery Control Module and Bracket Replacement)
* Control Module References (Programming and Relearning) for drive motor generator battery control module replacement, setup and programming