Hummer H3. Manual — part 1128

The duty cycle of the internal battery current sensor is less than 2 percent duty cycle or greater
than 98 percent duty cycle for greater than 240 seconds.

Action Taken When the DTC Sets

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.

The generator battery control module will request the driver information center (DIC)
message of Service Charging System. The battery indicator remains OFF.

Conditions for Clearing the DTC

The duty cycle of the internal battery current sensor is greater than 2 percent duty cycle or
less than 98 percent duty cycle.

Clear the DTC with a scan tool.

Diagnostic Aids

Recommended Action:

Clear the codes.

Cycle the ignition.

DTC B1566

IMPORTANT: You must cycle the ignition after clearing the DTC to turn OFF the

DIC message of Service Charging System.

Step

Action

Yes

No

Schematic Reference: Starting and Charging Schematics
Connector End View Reference: Engine Electrical Connector End Views

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to Step 2

Go to
Diagnostic
System Check -
Vehicle

2

1. Install a scan tool.

2. Clear DTC.

3. Cycle ignition.

Go to Testing
for Intermittent
Conditions and
Poor

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

DTC C0899

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 Descriptor

DTC C0899

Device Voltage Low

Circuit/System Description

The electronic brake control module (EBCM) monitors the ignition voltage level available for
system operation. A low voltage condition prevents the system from operating properly.

Conditions for Running the DTC

Ignition is ON.

Conditions for Setting the DTC

This fault will be set if the ignition voltage to EBCM is less than 9 volts for 100 msec.

Does DTC B1566 reset?

Go to Step 3 Connections

3

Replace the generator battery control
module. Refer to Control Module
References for replacement, setup and
programming.
Did you complete the replacement?

Go to Step 4

-

4

1. Use the scan tool in order to clear the

DTC.

2. Operate the vehicle within the

Conditions for Running the DTC, as
specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

Action Taken When the DTC Sets

Traction Control System (TCS) and Vehicle Stability Enhancement System (VSES) for the
duration of the ignition cycle.

The TCS indicator turns ON.

The driver information center (DIC) displays the Service Stability System message.

Conditions for Clearing the DTC

The condition for the DTC is no longer present.

The EBCM automatically clears the history DTC when a current DTC is not detected in 100
consecutive drive cycles.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Scan Tool Data Definitions

Circuit/System Testing

1. Measure and record the voltage at the battery terminals. With scan tool, observe the battery

voltage signal parameter. Verify that battery terminal voltage and battery voltage signal
readings do not differ more than 1 volt.

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

If more than 1 volt, test the battery positive voltage and ground circuits of the EBCM
for an open/high resistance or replace the EBCM.

2. Refer to Charging System Test.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup and programming

DTC C0901

Diagnostic Information

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 Descriptor

DTC C0901

Device 2 Voltage Low

Circuit/System Description

The electronic brake control module (EBCM) monitors the ignition 1 voltage (IGN1) level
available for system operation. A low voltage condition prevents the system from operating
properly.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

Ignition 1 (IGN1) voltage to EBCM is less than 6.5 volts for 7 seconds.

Vehicle speed is greater than 3 km/h (2 mph).

Action Taken When the DTC Sets

Brake Warning indicator turns ON.

2007 Hummer H3

2007 ENGINE Engine Electrical - H3