Hummer H3. Manual — part 634

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

Circuit/System Testing

1. Cycle the ignition from OFF to ON. Observe the accumulator pressure data parameter on

the scan tool. Fully apply and release the brake pedal once, the accumulator pressure should
hold steady above 16.7 MPa.

If the accumulator pressure data parameter does not hold steady above 16.7 MPa,
replace the accumulator.

2. Wait 60 seconds without depressing the pedal. The pump motor should not turn on.

If the ABS pump motor turns ON and OFF several times, replace the EBCM/brake
pressure modulator valve (BPMV) assembly.

3. Cycle the ignition from OFF to ON. Apply and release the brake pedal continuously. The

accumulator pressure should not be below 14.9 for 100 seconds consecutively.

If the accumulator pressure stays below 14.9 MPa for 100 seconds, replace the
EBCM/BPMV assembly.

4. Test drive the vehicle and observe the accumulator pressure data parameter while driving.

The accumulator should not fluctuate rapidly.

If the accumulator pressure fluctuates rapidly replace the EBCM/BPMV assembly.

Repair Procedures

IMPORTANT: If present, diagnose DTC C0110 or C0201 before DTC C0131. An

inoperative ABS motor or control can cause DTC C0131 to set.

IMPORTANT: Always perform the Diagnostic Repair Verification after

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

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

Hydraulic Brake Booster Accumulator Replacement

DTC C0136

DTC Descriptor

DTC C0136

Base Brake System Pressure Circuit

Diagnostic Fault Information

Circuit/System Description

The electronic brake control module (EBCM) monitors an internal input from the master cylinder
pressure sensor to enhance Antilock Brake System (ABS) braking and vehicle stability if
equipped.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

When vehicle speed is more than 7 km/h (4 mph), the master cylinder pressure does not
change for 30 seconds with the brake applied.

When vehicle speed is more than 10 km/h (6 mph), the master cylinder pressure signal is
erratic.

Master cylinder pressure signal is out of range.

Master cylinder pressure is high for 5 seconds with the stop lamp switch signal OFF.

Action Taken When the DTC Sets

The EBCM disables traction control system (TCS) and vehicle stability enhancement system
(VSES) for the duration of the ignition cycle.

completing the diagnostic procedure.

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to

using this diagnostic procedure.

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

The Stability Caution indicator turns on.

The driver information center (DIC) displays the TRACTION FAILED message.

DIC displays the SERVICE STAB SYS message.

An ECE 13 response may occur.

Conditions for Clearing the DTC

The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

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

Diagnostic Aids

The master cylinder pressure sensor is located internally in the BPMV and is not serviceable.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Exterior Lights 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 for EBCM

Circuit/System Testing

Note: Inspect for brake lamp related DTCs and symptoms before diagnosing DTC C0136.

Note: A binding brake pedal or misadjusted brake switch can cause DTC C0136 to set. Correct

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

any hydraulic brake symptoms before diagnosing this DTC. Refer to Symptoms - Hydraulic
Brakes .

Disconnect the EBCM harness connector. Connect a test lamp between the stop lamp switch
signal circuit and ground. Apply the brake.

If the test lamp does not illuminate but the center high mounted stop lamp (CHMSL) does
illuminate, repair open in the stop lamp switch signal circuit.

If the test lamp and CHMSL does not illuminate, go to Symptoms - Lighting Systems .

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

Repair Procedures

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

Symptoms - Lighting Systems

DTC C0161

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 C0161

ABS Brake Switch Circuit

Circuit/System Description

The brake switch supplies battery positive voltage to the electronic brake control module
(EBCM) when the brake pedal is applied.

Conditions for Running the DTC

IMPORTANT: Always perform the Diagnostic Repair Verification after

completing the diagnostic procedure.

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3