2010 Cadillac Truck Escalade RWD V8-6.2L Page 1543
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.
瀚慖f the voltage is less than 194 V, replace the drive motor generator battery.
瀚慖f the voltage is between 194-230 V, perform the jump assist. Refer to Jump Assist ().
瀚慖f 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.
瀚慖f 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.
瀚慖f 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 (See: Verification Tests) after completing the repair.
* Drive Motor Generator Battery Replacement and Shipping Preparation ()
* Control Module References (See: Testing and Inspection/Programming and Relearning) for drive motor generator battery control module
replacement, setup and programming
P1A4E
DTC P1A1F or P1A4E
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 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
