2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 245

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 245

DTC Descriptors

DTC B137A 01

- Hybrid Accessory Wake Up Circuit - Short to Battery

DTC B137A 06

- Hybrid Accessory Wake Up Circuit - Short to Ground or Open

Diagnostic Fault Information

Circuit/System Description

Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation.

Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are

needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are

used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the

transmitter module.

The wake up signal circuit is energized by the serial data gateway (SDG) module to activate the drive motor generator power inverter module

(PIM) and the drive motor generator battery control module. If the wake up signal is not responded to by all three modules, this DTC sets in the

SDG module.

Conditions for Running the DTC

* The system voltage is between 9-16 volts.

* The vehicle power mode master requires serial data communication to occur.

Conditions for Setting the DTC

A short circuit exists on the wake up signal circuit of the SDG module.

Action Taken When the DTC Sets

The malfunction indicator lamp (MIL) illuminates and the driver information center (DIC) displays the message Service Hybrid System.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.

* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

Reference Information

Schematic Reference

* Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical

Diagrams)

* Hybrid Controls Schematics ()

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Description and Operation

Data Link Communications Description and Operation (See: Powertrain Management/Computers and Control Systems/Information

Bus/Description and Operation)

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)