C0287

Antilock Brake System

Diagnostic Information and Procedures

DTC C0287, P1644, or P1689

Circuit Description

The EBCM supplies 5 VDC to the powertrain control module (PCM) on the delivered torque signal circuit. The PCM toggles this voltage to ground in order to create the delivered torque signal at the EBCM. A signal with a frequency of 128 Hz +/- 5 percent and a duty cycle of 25-95 percent is a valid delivered torque signal. The percentage of duty cycle is proportionate to the percentage of delivered torque.

Conditions for Running the DTC

The ignition is ON.
The engine is running at a speed greater than 450 RPM for 1 second.

Conditions for Setting the DTC

C0287

The EBCM receives an invalid delivered torque signal for 300 milliseconds.

P1689

The PCM detects the delivered torque signal voltage as being less than 4.75 volts or greater than 5.25 volts.

Action Taken When the DTC Sets

The EBCM disables the TCS.
The traction off indicator turns ON.

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 Electrical Intermittents, Testing for Intermittent and Poor Connections, Wiring Repairs and Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3. This step tests for voltage supplied to the PCM from the EBCM.
9. The PCM may be damaged if the delivered torque signal circuit is shorted to voltage.

DTC C0287, P1644, Or P1689 Steps 1 - 4:

DTC C0287, P1644, Or P1689 (cont'd) Steps 5 - 12: