2010 Cadillac Truck Escalade RWD V8-6.2L Page 1541
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
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.
