Hummer H3. Manual — part 631

Action Taken When the DTC Sets

The EBCM disables the Traction Control System (TCS)/Vehicle Stability Enhancement
System (VSES) for the duration of the ignition cycle.

Driver information center (DIC) displays the TRACTION FAILED message.

DIC displays the SERVICE STAB SYS message.

Stability Caution indicator turns ON.

Conditions for Clearing the DTC

The DTC clears automatically from current status when the fault is corrected and the ignition is
cycled. Use a scan tool to clear the DTC from history status.

Diagnostic Aids

B0010 sets if all of the reverse lamp bulbs are open.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Exterior Lights Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Data Communication 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

Circuit/System Testing

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

1. Turn ON the ignition with the engine OFF. Place the gear selector of the transmission in

reverse. The reverse lamps should illuminate.

If the reverse lamps do not illuminate, go to Diagnostic Aids or Symptoms -
Lighting Systems .

2. Turn the ignition OFF. Disconnect the EBCM harness connector. Connect a test lamp

between the backup lamp supply voltage circuit of the harness connector and ground. Turn
the ignition ON and place the gear selector of the transmission in reverse.

If the test lamp does not illuminate, repair open in the backup lamp supply voltage
circuit between the splice and the EBCM connector.

If the test lamp illuminates, replace the EBCM/brake pressure modulator valve (BPMV)
assembly.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM and BPMV replacement, setup and programming

Symptoms - Lighting Systems

DTC B2745

DTC Descriptor

DTC B2745

Traction Control Switch Circuit

Diagnostic Fault Information

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

DTC B2745

Circuit/System Description

The driver may disable the Traction Control System (TCS) by pressing the traction control

Circuit

Short to

Ground

Open/High

Resistance

Short to
Voltage

Signal

Performance

TCS switch signal circuit

B2745

12

-

-

1. Traction control cannot be manually disabled.

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

switch. The body control module (BCM) supplies a 12-volt signal on the traction control signal
circuit. When the traction control switch is pressed, this voltage signal is grounded.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The BCM detects low voltage on the traction control signal circuit for 60 seconds.

Action Taken When the DTC Sets

The BCM sends a serial data message to the electronic brake control module (EBCM)
informing the EBCM that the desired TCS state cannot be determined.

The EBCM defaults the TCS status to enabled.

Conditions for Clearing the DTC

The DTC clears automatically from Current status when the fault is corrected. Use a scan tool to
clear the DTC from history status.

Diagnostic Aids

An intermittent short to ground on the traction control signal circuit is the most likely cause of a
history DTC when no problem is found. When the Conditions for Setting this DTC are present,
the driver is not able to disable traction control.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

SIR Connector End Views

Data Communication Connector End Views

Electrical Information Reference

Circuit Testing

Connector Repairs

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

Traction control can be disabled/enabled when the traction control switch is pressed and released.

Circuit/System Testing

1. Turn OFF the ignition for 5 seconds, then turn ON the ignition and wait at least 60 seconds.

If DTC B2745 does not reset, go to Diagnostic Aids.

2. Turn the ignition OFF. Disconnect the traction control switch harness connector. Turn the

ignition ON and wait at least 60 seconds.

If DTC B2745 does not reset, replace the traction control switch.

If the DTC B2745 resets, check the TCS switch signal circuit for a short to ground or
replace the BCM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Accessory Switch Replacement

Control Module References for BCM replacement, setup and programming.

DTC C0035-C0050

DTC Descriptor

DTC C0035

Left Front Wheel Speed Sensor Circuit

DTC C0040

Right Front Wheel Speed Sensor Circuit

DTC C0045

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3