2010 Cadillac Truck Escalade RWD V8-6.2L Page 1255
Circuit/System Description
The system contains twenty battery modules. Each module contains two 7.2 V cells for a total nominal system voltage of 288 V. Each battery
module is rated at 14.4 V direct current (DC) and all the modules are connected together in series. The drive motor generator battery is also referred
to as the hybrid battery. 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 monitors the hybrid battery voltage on the twenty battery modules. 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 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. They hybrid powertrain control module is the host controller for diagnostic trouble code (DTC) information.
Conditions for Running the DTC
* The ignition is ON.
* The 12 V battery voltage is 9-18 V.
* High voltage contactors are closed.
Conditions for Setting the DTC
DTCs P0B3C, P0B41, P0B46, P0B4B, P0B50, P0B55, P0B5A, P0B5F, P0B64, P0B69, P0B6E, P0B73, P0B78, P0B7D, P0B82, P0B87,
P0B8C, P0B91, P0B96
The voltage of any two consecutive batteries multiplied by 20 is 70 V greater than or less than the total pack voltage for 16 seconds.
DTC P0B9B
The voltage of battery 20 multiplied by 20 is 70 V greater than or less than the total pack voltage for 16 seconds. DTC P0B9B only requires one
voltage failure because battery 20 is the last battery.
Action Taken When the DTC Sets
* DTCs P0B3D, P0B42, P0B47, P0B4C, P0B51, P0B56, P0B5B, P0B60, P0B65, P0B6A, P0B6F, P0B74, P0B79, P0B7E, P0B83, P0B88,
P0B8D, P0B92, P0B97, and P0B9C are type B DTCs.
* The drive motor generator battery control module commands the battery vent fan to high speed.
* If more than 4 of these DTCs are set, the drive motor generator battery sends a message to the hybrid powertrain control module to reduce the
power use limit to 50 percent.
Conditions for Clearing the DTC
DTCs P0B3C, P0B41, P0B46, P0B4B, P0B50, P0B55, P0B5A, P0B5F, P0B64, P0B69, P0B6E, P0B73, P0B78, P0B7D, P0B82, P0B87, P0B8C,
P0B91, P0B96, and P0B9B are type B DTCs.
Reference Information
Schematic Reference
Hybrid Energy Storage Schematics ()
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Drive Motor Battery System Description ()
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
