The EBCM receives the rear wheel speed signal from the Vehicle Control Module (VCM) for gas engine vehicles or the Vehicle Speed Sensor Buffer for diesel engine vehicles. The rear wheel speed signal originates from the Vehicle Speed Sensor (VSS) which is connected to the VCM (gas) or the Vehicle Speed Sensor Buffer (diesel) .

EBCM losing the rear wheel speed signal for at least 5 seconds while the vehicle is moving above 13 km/h (8 mph) with the brake pedal released.

DTC C0236 is an Ignition Latched DTC, which indicates that the above actions are true until the ignition is turned to OFF (even if the cause of the DTC is intermittent).

This malfunction can be caused by a malfunction in the EBCM, VCM (gas) Vehicle Speed Sensor Buffer (diesel), VSS or a fault in CKT 821, CKT 822 or CKT 1827.

Before performing any diagnostics on the ABS, resolve any Vehicle Speed Sensor (VSS) DTC's currently set in the VCM.

In addition, any of the following conditions may cause an intermittent malfunction:

Thoroughly check any circuitry that is suspected of causing the intermittent complaint for the following conditions:

If the customer says that the ABS indicator lamp is on only during humid conditions such as rain, snow, or vehicle wash, then thoroughly inspect the suspected circuits for signs of water intrusion. Use the following procedure:

1. Spray the suspected area with a 5 % salt water solution (two teaspoons of salt to 12 oz. of water)
2. Drive the vehicle above 24 km/h (15 mph) for at least 30 seconds

If the DTC returns, replace the suspected harness.

The numbers below refer to the steps in the diagnostic table:

2. This step uses the voltage output from the VCM (gas) or Vehicle Speed Sensor Buffer (diesel) to check the CKT 1827.

3. This step checks the CKT 1827 for proper resistance.

5. This step checks for a short in the wiring between the ECBM and the VCM.