GM Service Manual Online
For 1990-2009 cars only

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 00: Steering Wheel Sensor Malfunction

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Serial Data Bus+ (between the EBCM and the steering angle sensor)

--

U1651 00

--

--

Serial Data Bus- (between the EBCM and the steering angle sensor)

--

U1651 00

--

--

Steering Angle Sensor Ignition

--

U1651 00

--

--

Steering Angle Sensor Ground

--

U1651 00

--

--

Circuit Description

The electronic brake control module (EBCM) monitors the received messages from the steering angle sensor for corruption or for missing messages.

Conditions for Running the DTC

    • Ignition ON.
    • The vehicle speed is greater than 40 km/h (25 mph).

Conditions for Setting the DTC

The EBCM receives a corrupt or a missing message after 100 milliseconds.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the traction control system (TCS)/vehicle stability enhancement system (VSES) and for the duration of the ignition cycle.
    • The Stability Off indicator illuminates.

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.

Diagnostic Aids

Possible causes of this DTC are as follows:

    • An open in the Serial Data + or Serial Data -circuit
    • An open in the ignition circuit
    • An open in the ground circuit
    • Malfunctioning steering angle sensor
    • Malfunctioning EBCM

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Important: With a DMM, test the following circuits for possible malfunction:

   •  Serial Data + and Serial Data - circuits between the EBCM and the steering angle sensor for an open.
   •  Steering angle sensor ground circuit for an open.
   •  Steering angle sensor ignition circuit for an open.

  1. With the scan tool perform the EBCM VSES scan tool special functions Steering Angle Sensor Centering procedure.
  2. If the steering angle sensor procedure is not successful, test or replace the steering angle sensor.
  3. Test drive the vehicle under code setting conditions.
  4. If DTC U1651 resets, test or replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Steering Angle Sensor Centering
    •  Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement
    •  Control Module References for EBCM replacement, setup, and programming