325 ABS

Circuit Description
The EBCM receives the rear wheel speed signal from the VCM (4.3L) or the PCM (2.2L). The signal from the VCM/PCM is always high (12 Volts) when the ignition is on and the vehicle is not moving. When the vehicle is moving, the VCM/PCM toggles this voltage on and off. The EBCM uses the frequency of this signal to calculate the rear wheel speed.

Conditions for Running the DTC
^ The ignition is ON.
^ The front wheel speed sensor signals are both greater than 13 km/h (8 mph).

Conditions for Setting the DTC
The rear wheel speed sensor signal is less than 6 km/h (4 mph) for 5 seconds.

Action Taken When the DTC Sets
^ The ABS, BRAKE and TRACTION OFF (if equipped with traction control) indicators are commanded on.
^ The ABS, DRP and Traction Control (if equipped) are disabled for as long as the malfunction is present.

Conditions for Clearing the DTC
^ Repair the conditions responsible for setting the Diagnostic Trouble Code (DTC).
^ Use a scan tool in order to clear the DTC.
^ After the DTC is cleared and the ignition is ON, the ABS indicator remains on until the EBCM completes a power-up self-test. This test concludes when the vehicle reaches a speed of 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. Inspect for the following:
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Corrosion
^ Improperly formed or damaged terminals
^ Poor terminal-to-wiring connections
^ Physically damaged wiring
^ Wiring broken inside the insulation

Test Description





The number below refers to the step number on the diagnostic table.
3. This step tests if the VCM/PCM is sending a vehicle speed signal to the EBCM. The voltage should measure approximately 50% of battery voltage while the driveshaft is rotating.