For 1990-2009 cars

### Diagnostic Instructions

• | Perform the 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 Descriptors

DTC C0460 00 : Steering Position Signal
DTC C0460 39 : Steering Position Signal
DTC C0460 42 : Steering Position Signal Initialization Not Accomplished
DTC C0460 4B : Steering Position Signal Calibration Not Accomplished
DTC C0460 5A : Steering Position Signal Not Plausible
DTC C0460 71 : Steering Position Signal Internal Failure
DTC C0460 72 : Steering Position Signal Rolling Count Invalid

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Steering Wheel Position Sensor 12 Volt Reference Voltage | C0292 | C0292 | C0292 | --
Low Reference | C0460 00 | C0460 00 | -- | --
Steering Wheel Position Signal Can HI | C0460 00 | C0460 00 | -- | C0460 42, 4B, 5A, 71, 72
Steering Wheel Position Signal Can Lo | C0460 00 | C0460 00 | -- | C0460 42, 4B, 5A, 71, 72

### Circuit/System Description

The steering angle sensor shares a 12-volt ignition supply voltage with the electronic brake control module (EBCM) and the yaw-rate/lateral sensor. The EBCM applies a ground to the steering angle sensor low reference circuit, which is shared with the yaw-rate/lateral sensor. If equipped, this vehicle received the steering wheel position signal from the power steering control module (PSCM) over GMLAN.

The steering angle sensor provides a GMLAN signal output to the EBCM that represents the steering wheel degree of rotation. The EBCM utilizes this signal to calculate the driver intended driving direction.

### Conditions for Running the DTC

• | The ignition is ON.

• | Ignition voltage is greater than 9.5 volts.

### Conditions for Setting the DTC

• | Steering angle sensor is reporting an internal electronic failure.

• | Steering angle sensor has not been initialized.

• | Steering angle sensor offset is greater than 15 degrees.

### Action Taken When the DTC Sets

• | Vehicle stability enhancement system (VSES) are disabled.

• | The VSES indicator turns ON

• | The driver indicator turns ON

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

• | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Diagnostic Aids

• | If DTC C0292 is set, diagnose that DTC first.

• | If the steering wheel position sensor is disconnected, DTCs will set and the EBCM will not provide 12-volt reference.

• | A poor ground connection for the EBCM may cause this DTC to set.

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Antilock Brake System Connector End Views

#### Description and Operation Reference

ABS Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Scan Tool Data List for EBCM

Steering Angle Sensor Centering

### Circuit/System Verification

1. Position the steering wheel to the straight-ahead, centered, position.
2. Install a scan tool, ignition ON, engine OFF, and view steering wheel position , the signal should be approximately 0° with the steering wheel straight ahead and should varies approximately 720+ or 720-.
3. As the steering wheel is turned, signal should travel smoothly between 720°+ 720°-.

### Circuit/System Testing

1. Ignition OFF, disconnect the steering wheel position sensor (SWPS) connector.
2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit and ground.

⇒ | If greater than 1 ohm, test the low reference circuit and the EBCM ground circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the EBCM.

3. Test the CAN Hi circuit, CAN Lo circuit, 12-volt reference circuit, and the low reference circuit for an open/high resistance or a short to voltage or ground.

⇒ | If all circuits test normal, perform the steering positions calibration in EBCM, and Scan Tool Output Control.

⇒ | If all circuits test normal, and the steering positions calibration failed, replace the SWPS.

⇒ | If the DTC sets again after replacing the SWPS, replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Electronic Brake Control Module Replacement

• | Control Module References for EBCM replacement, setup, and programming