2010 Cadillac Truck Escalade RWD V8-6.2L Page 1284

2010 Cadillac Truck Escalade RWD V8-6.2L Page 1284

- Hybrid Battery 19 Circuit Low Voltage

DTC P0B9C

- Hybrid Battery 20 Circuit Low Voltage

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. The hybrid powertrain control module is the host controller for diagnostic trouble code (DTC) information.

Conditions for Running the DTC

* DTC P0A1F is not set.

* The ignition is ON.

* The 12 V battery voltage is 9-18 V.

Conditions for Setting the DTC

P0B3D, P0B42, P0B47, P0B4C, P0B51, P0B56, P0B5B, P0B60, P0B65, P0B6A, P0B6F, P0B74, P0B79, P0B7E, P0B83, P0B88, P0B8D,

P0B92, and P0B97

Any two consecutive hybrid battery voltages are less than 7.5 V for 1.5 seconds.

P0B9C

Hybrid battery number 20 voltage is less than 7.5 V for 1.5 seconds. DTC P0B9C 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 control module sends a message to the hybrid powertrain control

module to reduce the power use limit to 50 percent.

Conditions for Clearing the DTC

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.

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)