A014

Circuit Description
Ignition voltage is supplied through terminal "86" 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 enable relay contacts and allows battery voltage and current to be supplied to the EMBs and EBCM, which supplies power to the motors and solenoids.

Failure Condition
DTC A014 can be set anytime after the EBCM commands the enable relay "ON" (the relay is first commanded "ON" during the three second bulb check). This test monitors the availability of current/voltage to the motors, solenoids and EMBs. This malfunction indicates voltage is not available and would therefore not allow ABS operation if required.

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

Test Description
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step would indicate that the EBCM is sensing battery voltage present through the relay contacts at terminal "A." This shows that the relay and circuitry is functional.
2. This step ensures the enable relay and related circuitry are operating properly.
3. This ensures that battery voltage is available to terminals "30" and "86" of the relay.
4. This step checks for an open in CKT 850 between the enable relay and EBCM.
5. This step checks for an open in CKT 879 between enable relay and EBCM.
6. This test ensures malfunction was not due to poor harness connections.

Diagnostic Aids
An "Intermittent" malfunction may be 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 as described in "Enhanced Diagnostics."

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.

Vibration, Temperature Effects
Check for vibration effects by performing the relay test function of the Tech 1.

With the relay commanded "ON," lightly tap the top and sides of the relay while monitoring relay voltage. If the relay voltage changes significantly, replace the relay.

If test 14 only fails when the vehicle is initially started in cold ambient conditions (temperature less than 32°F - 0°C), replace the relay.