Antilock Braking System (ABS)

Fig. 344 Code 16: Electronic Brake Control Relay Coil Circuit Open:

Electronic Brake Control Relay Coil Circuit Open:

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 power to the motors and solenoids.

DTC Will Set When:
DTC 16 can be set anytime after the electronic brake control relay is commanded "ON." This test detects an open in the electronic brake control relay coil circuit. An open in this circuit will not allow the electronic brake control relay to be energized thus preventing power to the motors, EMB's and solenoids. A code 86 will be set with code 16 if the rear channel is not expected to be in the home position.

Action Taken:
A malfunction DTC is stored, ABS is disabled and the "ABS" warning lamp is turned "ON."

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 that there is continuity through the pull-in coil of the electronic brake control relay.
3. Checks to ensure that voltage is available to the pull-in coil of the electronic brake control relay.
4. Checks continuity in the electronic brake control relay control circuit.
5. Ensures DTC was not set due to a poor connection.
6. Identifies whether the malfunction is due to a poor connection or the EBCM.
7. 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.

If the frequency of the malfunction is high, but is currently intermittent, check for high coil resistance by measuring resistance between relay terminals "86" and "85." If resistance is greater than 100 ohms, replace the relay.

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.