C0238

C0238 or C038

Circuit Description
The rate at which the wheel/vehicle speed sensor ring makes a full 360 degrees rotation is directly related to the circumference of the tire(s).

Conditions for Running the DTC
^ The ignition is ON.
^ The vehicle is moving at a speed greater than 24 km/h (15 mph) and less than 80 km/h (50 mph).

Conditions for Setting the DTC
The EBCM detects that one speed sensor signal is at least 10% greater than or less than the other speed sensor signals.

Action Taken When the DTC Sets
^ The ABS and BRAKE indicators are commanded on.
^ The ABS is disabled for the remainder of the ignition cycle.

Conditions for Clearing the DTC
^ Repair the condition(s) responsible for setting the DTC.
^ Use the scan tool in order to clear the DTC.

Diagnostic Aids
Installing one front tire or one rear tire of significantly different size on the vehicle will set DTC C0238 Operating the vehicle with a tire that has very low air pressure may also set this DTC. Inspect the vehicle for an incorrect or damaged wheel speed sensor(s) or vehicle speed sensor if the tires and the EBCM and VCM/PCM calibrations are OK.

Test Description

4. If the front tires are not the same size as the rear tires, the EBCM calibration must match the FRONT tire size and the VCM/PCM calibration must match the REAR tire size.