Hummer H3. Manual — part 641

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Description and Operation

ABS Description and Operation

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

Test drive the vehicle at a speed greater than 15 km/h (9 mph) and make several turns. The DTC
should not reset.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the SWPS.

2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit terminal 8

and ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Test for less than 1 ohm of resistance between the low reference circuit terminal 2 and

ground.

If greater than the specified range, test the low reference circuit for an open/high
resistance. If the circuit tests normal, replace the EBCM.

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 7 and

ground.

If the test lamp does not illuminate, test the ignition circuit for a short to ground or an
open/high resistance. If the circuit tests normal and the fuse is OK, replace the HVAC
relay 87.

5. Test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and ground.

If less than the specified range, test the 5-volt reference circuit for a short to ground or
an open/high resistance. If the circuit tests normal, replace the EBCM.

If greater than the specified range, test the 5-volt reference circuit for a short to
voltage. If the circuit tests normal, replace the EBCM.

6. Test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and the signal terminal

6.

If less than the specified range, test the signal circuit for an open/high resistance. If the
circuit tests normal, replace the EBCM.

If greater than the specified range, test the signal circuit for a short to voltage. If the
circuit tests normal, replace the EBCM.

7. Reconnect the SWPS.

8. Disconnect the EBCM C2 harness connector.

9. Ignition OFF, test for infinite resistance between the signal circuit pin 39 and ground.

If less than the specified range, test the signal circuit for a short to ground.

10. Ignition ON, test for an ignition voltage pulse between ground and the signal A circuit

terminal 23 and signal B circuit terminal 22 while turning the steering wheel.

If not the specified value, test the signal circuits for a short to voltage, short to ground
or an open/high resistance. If the circuit tests normal, replace the SWPS.

11. Position the wheels straight and the steering wheel within 10 degrees of center.

12. Test for ignition voltage between the marker pulse signal circuit terminal 8 and ground.

If less than the specified range, test the signal circuit for a short to ground or an
open/high resistance. If the circuit tests normal, replace the SWPS.

13. Center the front wheels and steering wheel. Observe the scan tool Analog Steering Position

Sensor data parameter for less than 180° or greater than -180°.

14. If not the specified value replace the SWPS.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement

Control Module References for EBCM replacement, setup and programming

DTC U1651

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 U1651

Chassis System Dedicated Bus Sensor 1 Malfunction

Circuit/System Description

The yaw rate, lateral and longitudinal accelerometers are combined into one combination sensor
external to the electronic brake control module (EBCM). The combination sensor receives
ignition power and a ground that is separate from the EBCM. The combination sensor sends
dedicated serial data messages to the EBCM regarding vehicle yaw rate, lateral and longitudinal
acceleration.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

Ignition voltage to the yaw/lateral combination sensor is less than 9.5 volts.

Communication is lost between the EBCM and the combination sensor.

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.

The Stability Caution indicator turns on.

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3

The DIC displays the SERVICE STAB SYS message.

The DIC displays the TRACTION FAILED message.

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.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Description and Operation

ABS Description and Operation

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 Verification

Verify that the following DTCs are not set: C0186 or C0196.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

Circuit/System Testing

2007 Hummer H3

2007 BRAKES Antilock Brake System - H3