GM Service Manual Online
For 1990-2009 cars only

For a full page schematic, refer to Steering Assist Schematics .

Circuit Description

The steering wheel position/speed sensor is a 0 to 5 volt device which is used to measure steering wheel position. The valid output voltage range from the sensor is 0.35 to 4.75 volts. The output voltage will increase or decrease within the valid voltage range as the steering wheel is rotated. Vehicles that are not equipped with the Z55 option (RTD) have only 1 signal used by the body control module (BCM). The sensor is mounted at the base of the steering column.

Conditions for Running the DTC

Vehicle speed is greater than 50 MPH for at least 10 seconds.

Conditions for Setting the DTC

The body control module detects a steering handwheel position/speed sensor out-of-range condition when the vehicle speed is greater than 50 MPH for at least 10 seconds.

Action Taken When the DTC Sets

The electronic variable orifice (EVO) outputs will be disabled for the remainder of the ignition cycle.

Conditions for Clearing the DTC

    • The body control module no longer detects a steering wheel speed/position sensor out-of-range condition.
    • A history DTC will clear after not seeing the malfunction for 100 consecutive ignition cycles.
    • Using the scan tool.

Diagnostic Aids

The following conditions may cause the malfunction to occur:

    • There is a short to ground or voltage in the signal circuit.
    • There is an open in the signal circuit.
    • Perform a visual inspection for loose or poor connections at all related components.
    • Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Verifies sensor voltage range.

  2. Tests for the proper operation of the circuit in the high voltage range.

  3. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.

  4. Tests for a short to ground and an open in the 5 volt reference circuit.

  5. Tests for a short to voltage, a high resistance, or an open circuit.

  6. The control module must be recalibrated when replacement is necessary.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the steering wheel position data parameter in the Body Control Module data list.

Does the scan tool indicate that the steering wheel position data parameter is within the specified range?

0.35 to 4.7 volts

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the steering handwheel position/speed sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the steering wheel position data parameter.

Does the scan tool indicate that the steering wheel position data parameter is greater than the specified value?

4.7 volts

Go to Step 4

Go to Step 8

4

  1. Turn OFF the ignition
  2. Connect a 3 amp fused jumper wire between the signal circuit of the steering wheel position/speed sensor and the sensor low reference circuit of the steering wheel position/speed sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the steering wheel position data parameter.

Does the scan tool indicate that the steering wheel position data parameter is less than the specified value?

0.35 volts

Go to Step 5

Go to Step 9

5

Test the 5 volt reference circuit of the steering handwheel position/speed sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 6

6

  1. Turn OFF the ignition
  2. Disconnect the fused jumper wire.
  3. Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the steering handwheel position/speed sensor and the signal circuit of the steering handwheel position/speed sensor.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the steering wheel position data parameter.

Does the scan tool indicate that the steering wheel position data parameter is greater than the specified value?

4.7 volts

Go to Step 15

Go to Step 12

7

Test the 5 volt reference circuit of the steering handwheel position/speed sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

8

Test the signal circuit of the steering handwheel position/speed sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

9

Test the signal circuit of the steering handwheel position/speed sensor for a short to voltage, a high resistance, or an open circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Test the sensor low reference circuit of the steering handwheel position/speed sensor for a high resistance, a short to voltage or an open circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

11

Inspect for poor connections at the harness connector of the steering handwheel position/speed sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

12

Inspect for poor connections at the harness connector of the body control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Replace the steering handwheel position/speed sensor. Refer to Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14

  1. Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control System.
  2. Program the BCM with the proper calibrations. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.
  3. Perform the learn procedure.

Did you complete the replacement?

--

Go to Step 15

--

15

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK