Part 1 of 5

CIRCUIT DESCRIPTION:
Ignition voltage is supplied through terminal "3" of the ABS enable relay. Then the EBCM is able to energize the pull-in coil by completing the ground circuit at pin "E59-11"of the EBCM. The magnetic field created closes the ABS enable relay contacts and allows battery voltage and current to be supplied to the solenoids and the EBCM, which supplies power to the motors.

FAILURE CONDITION:
DTC 14 can be set anytime after the EBCM commands the ABS enable relay on (the relay is first commanded on during initialization). This test monitors the availability of current/voltage to the motors and solenoids. This malfunction indicates voltage is not available and would therefore not allow ABS operation if required.

ACTION TAKEN:
A DTC 14 is stored, ABS is disabled and the "ABS" warning light is turned on or will flash. If the rear piston is not in the home position, the red "BRAKE" warning light will also be illuminated.

TEST DESCRIPTION:
Number(s) below refer to circled Number(s) on the diagnostic chart.
1. This step checks to see if the EBCM is sensing battery voltage at terminal "E58-7".
2. This step checks for proper operation of the ABS enable relay and related circuitry.
3. This step checks for excessive resistance in the switched battery input circuitry.
4. This step checks for excessive resistance in the B+ feed circuit.

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 of causing the intermittent malfunction 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 AND 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 DTC 14 only occurs when the vehicle is initially started in cold ambient conditions (temperature less than 0°C [32°F]), replace the relay.