C0045

Antilock Brake System

Diagnostic Information and Procedures

DTC C0045 or C0050

Circuit Description

As the wheel spins, the wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.

Conditions for Running the DTC

- The ignition is ON.
- The vehicle speed is greater than 13 km/h (8 mph).

Conditions for Setting the DTC

Any of the following conditions may cause the DTC to set.
- The EBCM detects an open wheel speed sensor circuit for 500 milliseconds.
- The EBCM detects a shorted wheel speed sensor circuit for 500 milliseconds.
- The EBCM detects the absence of a wheel speed sensor signal for 5 seconds. If more than one absent wheel speed sensor signal is detected, the condition must be present for 120 seconds to set DTC's.
- The EBCM detects an erratic wheel speed sensor signal for 200 milliseconds.

Action Taken When the DTC Sets

- The EBCM disables ABS/TCS/VSES and may disable DRP if more than one wheel speed sensor DTC is set.
- The ABS indicator turns ON.
- The traction off indicator turns ON.
- The message center displays the service stability system message.
- The brake warning indicator may turn ON.
- An ECE 13 response may occur. Refer to ABS Description and Operation (W/O JL4) ABS Description and Operation (W/JL4) for a complete description of ECE 13.

Conditions for Clearing the DTC

The Conditions for Setting the DTC are no longer present and you use the scan tool Clear DTC's function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Intermittent and Poor Connections, Connector Repairs, Testing for Electrical Intermittents and to Wiring Repairs in Wiring Systems.
If the customer's concern is that the ABS indicator is on only during humid conditions such as rain, snow or vehicle wash, thoroughly inspect the wheel speed sensor circuits for signs of water intrusion. Use the following procedure in order to help isolate the problem area:
1. Spray the suspected area with a 5 % salt-water solution.
2. Operate the vehicle at a speed greater than 13 km/h (8 mph) for at least 30 seconds.
Repair or replace the suspect harness if the DTC sets.

DTC C0045 Or C0050 Steps 1 & 2:

DTC C0045 Or C0050 Steps 3 - 11: