For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using the 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 C0252 00: Steering Wheel Position Sensor Uncorrelated

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Steering Wheel Position Sensor Uncorrelated | -- | -- | -- | C0252 00

### Circuit/System Description

The electronic brake control module (EBCM) supplies ground to the wheel speed sensor low reference circuit. The wheel speed sensor in conjunction with a pulse ring generates an AC signal voltage. The amplitude and frequency of the signal generated is proportional to the wheel speed. The EBCM monitors the wheel speed sensor signal voltage to determine the rotational speed of each wheel and to calculate the vehicle reference speed.

The EBCM compensates for normal long-term rotational wheel speed deviation if the difference does not exceed the predetermined parameters. These deviations may be caused by difference in tire wear or difference in tire pressure between the wheels.

### Conditions for Running the DTC

The EBCM receives a wheel speed sensor output signal.

### Conditions for Setting the DTC

The wheel speed deviation between the wheels is outside the EBCMs programming parameters.

### Action Taken When the DTC Sets

One or more of the following actions may occur:

• | The EBCM disables ESP for the duration of the ignition cycle.

• | The ABS warning lamp, the ABS warning icon and the Trac-Off icon activates.

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present.

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

### Diagnostic Aids

The following conditions can cause this concern:

• | Improper steering alignment

• | An open, a short to ground, or a short to voltage

• | An internal lateral accelerometer failure

• | An EBCM internal failure

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Component Connector End Views

#### 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

### Circuit/System Verification

1. With scan tool installed, clear the DTCs then drive the vehicle at a speed greater than 40 km/h (25 mph). If the DTC did not set as a current DTC see diagnostic aids.
2. If DTC C0035, C0040, C0045, or C0050 set as a current DTC also, refer to DTC C0035-C0050 .

### Circuit/System Testing

1. Ignition OFF, disconnect the yaw rate sensor/lateral accelerometer and the steering wheel position sensor connectors.
2. Ignition ON, measure for 4.8-5.2 volts at each 5-volt reference circuits and ground.

⇒ | If over 5.2 volts, test each 5-volt reference circuit for a short to voltage. If the circuits tests normal, replace the EBCM.

⇒ | If under 4.8 volts, test each 5-volt reference circuit for short to ground. If the circuits tests normal, replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming