For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle 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 Descriptor

DTC C0545 00: Steering Wheel Torque Input Sensor

### Circuit/System Description

The power steering control module (PSCM) uses the steering shaft torque as its main input for determining steering direction and the amount of steering assist needed. The steering column has an input shaft from the steering wheel to the torque sensor and an output shaft from the torque sensor to the intermediate shaft coupler. The input and output shafts are separated by a section of torsion bar at the base of the steering column where the torque sensor is located. The torque sensor consists of a detecting coil, compensation coil and 3 detecting rings. Detecting ring 1 is fixed to the output shaft while detecting ring 2 is fixed to the input shaft. Both detecting rings have toothed edges that face each other. The detecting coil is positioned around the toothed edges of detecting rings 1 and 2. As torsional twist is applied to the steering column shaft's torsion bar when the steering wheel is turned, these toothed edges change alignment with each other which effects the magnetic characteristics around the detecting coil, changing the coils impedance thus changing the sensor signal voltage input to the PSCM. The PSCM recognizes this change in detecting coil signal voltage as steering column shaft torque. The compensation coil is positioned around detecting rings 2 and 3, which do not change alignment with each other as the steering wheel is turned. This coil is used to compensate for the rotation of the steering shaft and also conditions that can effect circuit impedance, such as voltage, current and ambient temperature, for accurate torque detection.

### Conditions for Running the DTC

Ignition ON.

### Conditions for Setting the DTC

Internal failure of the torque sensor.

### Action Taken When the DTC Sets

• | The driver information center (DIC) displays the POWER STEERING warning message.

• | Slight steering effort imbalance

### Conditions for Clearing the DTC

• | When the condition is no longer present.

• | A history DTC will clear after 100 consecutive malfunction-free ignition cycles.

### Diagnostic Aids

The torque sensor is serviced with the steering column assembly.

### Reference Information

#### Schematic Reference

Power Steering Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Power Steering System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Verify that DTC C0545 is not set.

⇒ | If the DTC is set, replace the steering column.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Steering Column Replacement