DTC U1651. HUMMER H3 2008

For 1990-2009 cars only

Makes 🢒 HUMMER 🢒 2008 🢒 H3 🢒 Brakes 🢒 Antilock Brake System 🢒 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

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 voltage 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

Ignition 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 VSES for the duration of the ignition cycle.

•	A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

•	The condition for the DTC is no longer present.

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

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module Referencesfor scan tool information.

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

Important: It is recommend that the defective components be replaced, and not the complete brake master cylinder assembly.

Ignition OFF, disconnect the harness connector at the yaw rate/lateral and longitudinal accelerometer sensor.
Test for less than 1 ohm between the ground circuit terminal 4 and ground.

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

Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

Ignition OFF, disconnect the X2 harness connector at the EBCM.
Ignition ON, test for 0 volts between the CAN HI circuit terminal 11 and ground.

⇒	If greater than the specified value, test the CAN HI circuit for a short to voltage.

Test for 0 volts between the CAN LO circuit terminal 25 and ground.

⇒	If greater than the specified value, test the CAN LO circuit for a short to voltage.

Ignition OFF, test for infinite resistance between the CAN HI circuit terminal 11 and ground.

⇒	If not the specified value, test the suspect circuit for a short to ground.

Test for infinite resistance between the CAN LO circuit terminal 25 and ground.

⇒	If not the specified value, test the CAN LO circuit for a short to ground.

Test for less than 1 ohm of resistance between the CAN HI circuit terminal 11 and terminal 2.

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

Test for less than 1 ohm of resistance between the CAN LO circuit terminal 3 and terminal 25.

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

Test for infinite resistance between the CAN HI terminal 11 and the CAN LO terminal 25.

⇒	If not the specified value, test the CAN HI and CAN LO circuits for a short together.

If all circuits test normal, replace the Yaw Rate/Lateral sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Vehicle Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer Replacement