GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The steering wheel position sensor is a 0-5 volt device which is used to sense steering wheel position and turning speed. The valid signal voltage range of the sensor is 0.35-4.75 volts. The signal voltage will increase or decrease within the valid voltage range as the steering wheel is turned. The body control module (BCM) monitors the steering wheel position sensor signal voltage and transmits this data on the serial data line.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0472 Steering Hand Wheel Speed Sensor Signal Circuit
    • DTC C0473 Steering Hand Wheel Speed Sensor Signal Circuit

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The BCM detects that the analog steering signal circuit is open, shorted to ground or shorted to voltage.

Action Taken When the DTC Sets

The BCM sends a serial data message reporting the failed steering signal.

Conditions for Clearing the DTC

    • A current DTC will clear when the malfunction is no longer present.
    • A history DTC will clear after 100 consecutive malfunction-free ignition cycles or when the scan tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

    •  Testing for Electrical Intermittents
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Connector Repairs

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step test the circuitry in the high voltage range.

  2. This step test the circuitry in the low voltage range.

  3. This step tests the low reference circuit of the steering wheel position sensor.

Step

Action

Values

Yes

No

Schematic Reference: Body Control System Schematics

Connector End View Reference: Computer/Integrating Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Use the scan tool to clear the DTC.
  2. Start the engine.
  3. With the engine running, turn the steering wheel back and forth from lock to lock.

Does the DTC reset?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the steering wheel position sensor harness connector.
  3. Turn ON the ignition.
  4. Select the Body Control Module (BCM) Data List on the scan tool.
  5. Observe the Analog SWPS Signal parameter on the scan tool.

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

0.15 V

Go to Step 4

Go to Step 9

4

  1. Connect a 3-amp fused jumper wire between the steering wheel position 5-volt reference circuit and the analog steering signal circuit.
  2. Observe the Analog SWPS Signal parameter on the scan tool.

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

4.75 V

Go to Step 5

Go to Step 6

5

Use a DMM to measure the voltage between the steering wheel position 5-volt reference circuit and the steering wheel position low reference circuit.

Does the voltage measure greater than the specified value?

4.75 V

Go to Step 10

Go to Step 8

6

Test the 5-volt reference circuit of the steering wheel position sensor for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 14

Go to Step 7

7

Test the signal circuit of the steering wheel position sensor for an open or a short to ground. Refer to Testing for Short to Ground and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 14

Go to Step 11

8

Test the low reference circuit of the steering wheel position sensor for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 14

Go to Step 11

9

Test the signal circuit of the steering wheel position sensor for a short to voltage. Refer to Testing for Short to Ground and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

10

Inspect for poor connections at the harness connector of the steering wheel position sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 14

Go to Step 12

11

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

12

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

Did you complete the replacement?

--

Go to Step 14

--

13

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 14

--

14

  1. Use the scan tool to clear all DTCs from all modules.
  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