C0235

Antilock Brake System

Diagnostic Information and Procedures

DTC C0235-C0237 or P0609

Circuit Description

The PCM converts the data from the vehicle speed sensor to a 128k pulses/mile signal. The EBCM uses the vehicle speed signal from the PCM in order to calculate the rear wheel speed.

Conditions for Running the DTC

C0235

The ignition is ON.

C0236 and C0237

The ignition is ON.
The vehicle speed is greater than 32 km/h (20 mph) when the brake is applied or 19 km/h (12 mph) when the brake is released.

P0609

The ignition is ON.
The vehicle is not moving.

Conditions for Setting the DTC

C0235

The EBCM detects low voltage on the vehicle speed signal circuit for 500 milliseconds.

C0236

The rear wheel speed signal is less than 6 km/h (4 mph) for 5 seconds, or 120 seconds in order to set multiple missing sensor signal DTC's.

C0237

The EBCM detects an erratic rear wheel speed signal for 105 milliseconds.

P0609

The PCM detects low voltage on the vehicle speed signal circuit for 45 seconds.

Action Taken When the DTC Sets

If equipped, the following actions occur:

The EBCM disables the ABS/TCS/DRP.
The ABS indicator turns ON.
The TRACTION OFF indicator turns ON.
The red brake warning indicator turns ON.

Conditions for Clearing the DTC

Repair the condition responsible for setting the DTC.
Use a scan tool in order to clear the DTC.
After the DTC is cleared and the ignition is ON, the ABS indicator may remain ON until the EBCM completes a power-up self-test.
This test concludes when the vehicle reaches a speed greater than 13 km/h (8 mph) and the wheel speeds are verified by the EBCM.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Electrical Intermittents, Testing for Intermittent and Poor Connections, Wiring Repairs and Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3. This step tests for a voltage signal from the PCM.
4. This step tests for a missing or erratic vehicle speed signal from the PCM. An assistant may be required to perform this test.

DTC C0235 - C0237 Or P0609 Steps 1 & 2:

DTC C0235 - C0237 Or P0609 (cont'd) Steps 3 - 10: