Circuit Description
ABS equipped vehicles have wheel speed sensors at all four wheels. The front
wheel speed sensors monitor the speed of each wheel by placing a magnetic coupling
next to a toothed ring mounted on the axle of each wheel. The rear wheel speed sensors
monitor speed of each wheel with a magnetic coupling and a toothed ring internal
to the wheel bearings. These sensors produce an AC signal that the electronic brake
traction control module (EBTCM) uses to calculate the wheel speed. The signal frequency
changes with the wheel speed. DTC C0245 will set when the EBTCM cannot specifically
identify which wheel speed sensor is causing the malfunction, DTC C0245 will be in
history and the DTC associated with the malfunctioning sensor will be set along with
DTC C0245.
Conditions for Setting the DTC
DTC C0245 will set if the following conditions exist:
| • | The EBTCM detects a deviation between the left and the right rear wheel
speeds of greater than 6 km/h (3.75 mph) at a vehicle speed of less than 100 km/h
(62 mph) on vehicles equipped with TCS. |
| • | The EBTCM detects a deviation between the left and the right front wheel
speeds of greater than 10 km/h (6.25 mph) at a vehicle speed of less than 100 km/h
(62 mph). |
| • | The EBTCM detects a deviation between the left and the right rear wheel
speeds of greater than 6 percent of the vehicle speed at greater than 100
km/h (62 mph) on vehicles equipped with TCS. |
| • | The EBTCM detects a deviation between the left and the right front wheel
speeds of greater than 4 km/h plus 6 percent of the vehicle speed at
greater than 100 km/h (62 mph). |
| • | When this DTC sets, the EBTCM will disable the ABS, the Traction Control
and the Dynamic Rear Proportioning and turn on the antilock telltale. |
Diagnostic Aids
| • | It is very important to thoroughly inspect the wiring components and the
connectors. Failure to carefully and fully inspect the wiring and the connectors
may result in misdiagnosis, causing part replacement with reappearance of the malfunction. |
| • | Inspect any circuitry that may be causing the complaint for the following
conditions: |
| - | Improperly formed or damaged terminals |
| - | Poor terminal-to-wiring connections |
| - | Physical damage to the wiring harness |
| • | The following conditions may cause an intermittent malfunction: |
| - | Rubbed-through wire insulation |
| - | A broken wire inside the insulation |
| • | Possible causes for DTC C0245 to set: |
| - | Damaged or missing teeth on one or more if the wheel speed sensor rings. |
| - | Large grooves or gouges, or buildup of foreign material in the gaps between
the wheel speed sensor ring teeth. |
| - | A worn front hub bearing assembly, or a worn inner axle bearing which
allow the sensor to toothed ring gap to change excessively. |
