C1231

DTC C1231

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC C1231
- Steering Position Sensor Circuit Malfunction

Circuit/System Description

The electronic brake control module (EBCM) monitors the steering wheel position sensor signal for vehicle stability control (VSC) system operation.

Conditions for Running the DTC

Ignition is in the ON position

Conditions for Setting the DTC

The EBCM does not receive data from the steering wheel position sensor.

Action Taken When the DTC Sets

* The traction control and VSC is disabled.
* The VSC warning indicator turns ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Reference Information
Schematic Reference

Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Verify DTC U0073, U0123, U0124, or U0126 are not set?

• If DTC U0073, U0123, U0124, or U0126 is set, refer to appropriate DTC.

2. Verify no speed sensor, yaw rate sensor or deceleration DTCs are set?

• If any speed sensor, yaw rate sensor or deceleration DTCs are set, refer to appropriate DTC prior to diagnosing C1231.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Test for less than 1 ohm between the terminals 1, 13 and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, check for 11-14V between terminals, 12, 24, 34 and ground.

• If the voltage is not as specified, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the steering position sensor.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Brake Pressure Modulator Valve Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming