Antilock Braking System (ABS)

Fig. 345 Code 17: Electronic Brake Control Relay Coil Circuit Shorted To Ground:

Electronic Brake Control Relay Coil Circuit Shorted To Ground:

Circuit Description:
Ignition voltage is supplied through terminal "85" of the electronic brake control relay. The EBCM is then able to energize the pull-in coil by completing the ground circuit at terminal "22" of the EBCM. The magnetic field created closes the electronic brake control relay contacts and allows battery voltage and current to be supplied to the EMB's and EBCM, which supplies voltage to the motors and solenoids.

DTC Will Set When:
DTC 17 can be set before the EBCM commands the electronic brake control relay "ON." This test determines if the electronic brake control relay is energized when it should not be. This malfunction would not allow the electronic brake control relay to remove power to the ABS. If a second malfunction were to occur that requires the electronic brake control relay to be turned "OFF," that malfunction can not be removed if the relay can not be controlled.

Action Taken:
A malfunction DTC is stored. ABS is not disabled and the "ABS" warning lamp will remain "OFF."

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Indicates if the EBCM is capable of controlling the electronic brake control relay as commanded.
2. Ensures the electronic brake control relay or control circuit are not shorted to ground.
3. This step isolates the malfunction to either the electronic brake control relay or the electronic brake control relay control circuit.
4. Ensures short to ground is not due to physical damage of the circuitry.
5. Identifies whether the malfunction is due to a poor connection in the Dash to Engine connector.

Diagnostic Aids:
An "intermittent" malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.

The frequency of the malfunction can be checked by using the enhanced diagnostic function of the Tech 1.

Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.