GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Chevy Suburban - 2WD 🢒 Steering 🢒 Variable Effort Steering 🢒 DTC C0472 or C0473

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 uses this data to calculate lateral acceleration. When the BCM detects lateral acceleration is occurring less current is commanded to the Electronic Variable Orifice (EVO) Solenoid which increases steering assist during abrupt driving maneuvers.

NOTE: The BCM/ESC stores the DTCs scan tool data and special functions. However, the scan tool menu to access variable effort steering is located in chassis.

Conditions for Running the DTC

Anytime the key is in the on position.

Conditions for Setting the DTC

A short to ground, short to voltage, or an open in the steering wheel position sensor signal circuit.

Action Taken When the DTC Sets
    • DTC C0472, or C0473 is stored in memory.
    • The EVO outputs will be disabled for the remainder of the ignition cycle.

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.
    • Using the scan tool

Test Description

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

  1. Tests if the sensor is within the valid voltage range.

    2.

  2. Tests if the sensor is internally shorted to ground.

    3.

  3. Tests if the signal circuit is shorted to ground

    4.

  4. Tests if the 5 volt reference circuit is short to voltage or open.

    5.

  5. Program the BCM after replacement.

Step

Action

Value(s)

Yes

No

Schematic Reference: Steering Assist Schematics

1

Did you perform the Variable Effort Steering Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Variable Effort Steering

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 sensor data parameter in the Electronic Variable Orifice data list.

Does the scan tool display the steering wheel position sensor data parameter is within the specified range?

0.35-4.7 V

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

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

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

0.0 V

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 and the low reference circuit of the steering wheel position sensor harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the steering wheel position sensor data parameter.

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

0.35 V

Go to Step 5

Go to Step 9

5

  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 and the signal circuit of the steering wheel position sensor harness connector.
  4. Turn ON the ignition, with the Engine OFF.
  5. With a scan tool, observe the steering wheel position sensor data parameter.

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

4.7 V

Go to Step 7

Go to Step 6

6

Test the 5 volt reference circuit of the steering wheel position sensor for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

7

Test the 5 volt reference circuit of the steering wheel position sensor for a short to voltage 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 wheel position sensor for a short to ground. Refer to Testing for Short to Ground 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 wheel position sensor for a short to voltage 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 10

10

Test the low reference circuit of the steering wheel position sensor for a short to voltage 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 12

11

Inspect for poor connections at the steering wheel position sensor harness connector. 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 BCM harness connector. 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 wheel position sensor. Refer to Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14

Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

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