GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Terraza Ext. 🢒 Brakes 🢒 Park Brake 🢒 DTC C0460 or C0461

Circuit Description

The steering wheel position sensor supplies 2 analog inputs, Phase A and Phase B, to the electronic brake control module (EBCM). The 2 input signals are approximately 90 degrees out of phase. By interpreting the relationship between the 2 inputs, the EBCM can determine the position of the steering wheel and the direction of the steering wheel rotation.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0460 Steering Position Sensor
    • DTC C0461 Steering Position Sensor Range/Performance

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

C0460

One of the following conditions exists:

    • Both Phase A and Phase B are greater than 4.9 volts or less than 0.2 volt for 1.6 seconds.
    • The angle change in Phase A or Phase B is greater than 36 degrees between 2 consecutive signal samples.

C0461

The difference in the phase angle between Phase A and Phase B is greater than 16 degrees continuously for 0.25 second.

Action Taken When the DTC Sets

If equipped, the following actions will occur:

    • The EBCM disables vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • The driver information center (DIC) displays the Service Stability System message.

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 in Wiring Systems:

    •  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.

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

    3.

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

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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 VSES 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?

0.2 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?

4.8 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?

4.8 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 in Wiring Systems.

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 in Wiring Systems.

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 in Wiring Systems.

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 in Wiring Systems.

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 in Wiring Systems.

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 electronic brake control module (EBCM). 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 14

Go to Step 13

12

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

Did you complete the replacement?

--

Go to Step 14

--

13

Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems 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