Hummer H3. Manual - part 637

The longitudinal accelerometer output is greater than 1.5 g or less than -1.5 g for 7 200 ms
periods during the same ignition cycle.

The longitudinal accelerometer output does not change when the vehicle decelerates from
30 km/h (19 mph) to 0 km/h. If the condition occurs 16 consecutive times, the DTC is set.

Action Taken When the DTC Sets

The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS) for
the duration of the ignition cycle.

The ABS indicator turns ON.

The driver information center (DIC) displays the ABS FAULT message.

The DIC displays the TRACTION FAILED message.

Conditions for Clearing the DTC

The condition for setting 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.

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

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

Circuit/System Verification

With scan tool installed drive the vehicle in a straight line at a speed greater than 30 km/h (19
mph) and decelerate the vehicle to a stop several times. The scan tool Longitudinal

Accelerometer Sensor Signal parameter should show a change in M/S

output in sequence to the

vehicle deceleration.

Circuit/System Testing

1. Turn OFF the ignition. Disconnect the longitudinal accelerometer harness connector. Turn

ON the ignition. With a DMM, verify voltage between 4.4 and 5.6 on the LNG rate sensor
5-volt reference circuit.

If the voltage is above 5.6 volts, test for a short to power on the LNG rate sensor
circuit. If the circuit tests normal, replace the EBCM.

If voltage is below 4.4, test for an open or a short to ground on the LNG rate sensor
circuit. If the circuit tests normal, replace the EBCM assembly.

2. Turn OFF the ignition. At the longitudinal accelerometer harness connector, connect a test

lamp between the LNG low reference circuit and battery positive voltage. Verify the test
lamp illuminates.

If the test lamp does not illuminate check for an open in the LGN low reference
circuit. If the circuit tests normal, replace the EBCM assembly.

3. Connect a 3-amp fused jumper wire between the LNG rate sensor 5-volt reference circuit

and the longitudinal accelerometer signal circuit. Turn ON the ignition and observe the
longitudinal accelerometer parameter.

If the scan tool displays greater than 1.5g, replace the longitudinal position sensor.

If the scan tool displays less than 1.5g, test for an open or short to ground on the
longitudinal accelerometer signal circuit. If the circuit tests normal, replace the EBCM
assembly.

Repair Procedures

Vehicle Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer
Replacement

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

DTC C0201

IMPORTANT: Always perform the Diagnostic Repair Verification after

completing the diagnostic procedure.

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

DTC Descriptor

DTC C0201

Antilock Brake System (ABS) Enable Relay Contact Circuit

Diagnostic Fault Information

Circuit/System Description

The solenoid and pump motor relay are located within the electronic brake control module
(EBCM). The solenoid relay supplies battery voltage to all of the valve solenoids. Three pump
motor relays supply battery positive voltage to the pump motor when the EBCM commands the
pump motor on.

Conditions for Running the DTC

Ignition voltage is greater than 9.5 volts.

The solenoid relay is commanded ON.

Conditions for Setting the DTC

One or more of the fallowing conditions exists:

The EBCM detects an open in the battery positive voltage circuit to the solenoid valve
relay.

The EBCM detects a stuck open solenoid valve relay or an open circuit between the
solenoid valve relay and solenoid valves.

The EBCM detects an open in the battery positive voltage circuit to the solenoid valve
relay.

The EBCM detects that one or more of the pump motor relays is off when commanded on.

Action Taken When the DTC Sets

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

The ABS indicator turns ON.

The driver information center (DIC) displays the ABS FAULT message.

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 DIC displays the SERVICE STAB SYS message.

The DIC displays the TRACTION FAILED message.

The Brake Warning indicator turns ON.

Conditions for Clearing the DTC

The condition for setting 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.

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

Circuit/System Verification

With the scan tool, access the ABS special functions menu and perform the Solenoid Test and
ABS Motor test. The pump motor and solenoids should function without setting DTCs.

Circuit/System Testing

Disconnect the EBCM harness connector. Connect a test lamp to ground, at the EBCM harness
connector touch the test lamp probe to each of the 3 battery positive voltage circuits. The test

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

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