Hummer H3. Manual — part 33

Description and Operation

Charging System Description and Operation

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, clear the DTC and start the engine. Verify DTC B1516 does not set as current.

If the DTC sets, replace the GBCM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for GBCM replacement, setup, and programming

DTC B151B

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B151B

Current Sensor Polarity Error - GBCM

Circuit/System Description

2008 Hummer H3

2008 ENGINE Engine Electrical - H3

The generator battery control module (GBCM) monitors its internal battery current sensor for
many charging system operations, and also for diagnostic purposes. If reversed polarity of the
battery current is sensed, then DTC B151B will set.

Conditions for Running the DTC

The engine is not running.

DTC B1516 is not set.

Conditions for Setting the DTC

The GBCM detects positive battery current.

Action Taken When the DTC Sets

The regulated voltage control (RVC) is disabled.

Conditions for Clearing the DTC

The GBCM detects correct polarity of the battery current.

Diagnostic Aids

DTC B151B may set if a battery charger is used.

Reference Information

Schematic Reference

Starting and Charging Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Charging System Description and Operation

Electrical Information Reference

Circuit Testing

Connector Repairs

2008 Hummer H3

2008 ENGINE Engine Electrical - H3

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Verify that the GBCM is installed correctly. The GBCM should be installed on the negative

battery cables, with the sensor coil around the negative cables and facing away from the
battery, and with the harness connector facing toward the battery.

If the GBCM is installed backwards or incorrectly, remove and reinstall the GBCM.

2. Ignition ON, clear the DTC with the scan tool. Verify that DTC B151B does not set.

If the DTC sets, replace the GBCM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for GBCM replacement, setup, and programming.

DTC B1566

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B1566

Current Sensor Polarity Check - GBCM

Circuit/System Description

The generator battery control module (GBCM) monitors its internal battery current sensor for
many charging system operations, and also for diagnostic purposes. If reversed polarity of the
battery current is sensed, then DTC B1566 will set.

2008 Hummer H3

2008 ENGINE Engine Electrical - H3

Conditions for Running the DTC

The engine is running.

This diagnostic runs every 50 ms.

Conditions for Setting the DTC

The GBCM detects reverse polarity of the battery current.

Action Taken When the DTC Sets

The charge indicator turns ON.

The driver information center (DIC) displays the SERVICE CHARGSYS message.

The filtered battery current is set to 0.1 amp.

The generator field control circuit duty cycle is set to 100 percent, battery voltage defaults
to 13.8 volts.

Conditions for Clearing the DTC

The GBCM detects correct polarity of the battery current.

Reference Information

Schematic Reference

Starting and Charging Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Charging System Description and Operation

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

2008 Hummer H3

2008 ENGINE Engine Electrical - H3