C0245

DTC C0245

Circuit Description

The toothed wheel generates a voltage pulse as it moves past the wheel speed sensor (WSS). Each tooth-gap-tooth series on the wheel generates the pulses. The electronic brake control module (EBCM) uses the frequency of these pulses to determine wheel speed. The voltage generated depends on the air gap between the wheel speed sensor and the toothed wheel, and on the wheel speed.

This DTC will set when the EBCM cannot identify which wheel speed sensor is causing the malfunction. It is necessary to inspect all wheel speed sensors and associated wiring to determine the cause of the DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0245 Wheel Speed Signal Malfunction

Conditions for Running the DTC

* Vehicle speed is greater than 6 km/h (4 mph) with the brake pedal not applied
or
* Vehicle speed is greater than 15 km/h (9 mph) and the brake pedal is actuated.

Conditions for Setting the DTC

* Incorrect number of teeth on the toothed wheel
* Damaged or broken teeth on the toothed wheel
* Discontinuity or short in the wheel speed sensor wiring

Action Taken When the DTC Sets

Antilock brake system (ABS) action is disabled and the ABS warning lamp is 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.

Diagnostic Aids

DTC C0245 may be set by running the scan tool auto test if the throttle angle readings are not updating while in the data list mode. If this is the case, clear the DTCs, disconnect the scan tool, and road test the vehicle to at least 12 km/h (7 mph) to see if the DTC resets.

Inspect the toothed wheels for any large grooves, gouges, marks, etc. that might influence the tooth's signal at the wheel speed sensor. Also inspect for a buildup of foreign material in the gaps between the teeth in the toothed wheel. A buildup of foreign material may cause this malfunction.

A badly worn hub/bearing assembly may cause this malfunction. The wheel speed sensor-to-toothed wheel air gap may change excessively due to bearing play. If an improper rear hub assembly or front outer constant velocity joint is installed, one with a toothed wheel containing the incorrect number of teeth, this DTC can set. Be sure that the front and the rear toothed wheel have 47 and 29 teeth.

Test Description

The numbers below refer to the step numbers on the diagnostic table.
2. This step begins the examination of the front wheel speed sensors.
3. This step inspects for a problem with one of the front toothed rings.
5. This step inspects the front wheel speed sensors.
7. This step inspects for shorts in a front wheel speed sensor harness.
9. This step inspects for opens in a front wheel speed sensor harness.
11. This step begins an inspection of the rear wheel speed sensors.
13. This step inspects for a problem with one of the rear toothed rings.
15. This step inspects the rear wheel speed sensors.
17. This step inspects for shorts in a rear wheel speed sensor harness.
19. This step inspects for opens in a rear wheel speed sensor harness.