A018

Fig. 468 Code 18: ABS Enable Relay Coil Circuit Shorted To Battery:

ABS Enable Relay & Circuit:

Circuit Description:
Ignition voltage is supplied through terminal "1" of the ABS enable relay. The EBCM then is able to energize the pull-in coil by completing the ground circuit at pin "22" of the EBCM. The magnetic field created closes the ABS enable relay contacts and allows battery voltage and current to be supplied to the EBCM which supplies power to the motors and solenoids.

Failure Condition:
DTC A018 can be set after the EBCM commands the ABS enable relay on. This test monitors the availability of current/voltage to the motors and solenoids; therefore, ABS operation would not be allowed if required.

Action Taken:
A DTC A018 is stored, ABS is disabled and the "ABS" indicator is turned on or flashes. If the rear piston is not in the home position, the red "BRAKE" indicator will also be illuminated.

Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step indicates if the EBCM is capable of controlling the ABS enable relay as commanded.
2. With the ABS enable relay removed, voltage should not be available at terminal "4". Any voltage at this point would indicate that CKT 879 was shorted to a voltage source.
3. This step checks for a shorted coil.
4. This ensures malfunction was not due to a poor connection.