DTC 54

DTC 54 Rear Channel In Release Too Long.:

DTC 54 Rear Channel In Release Too Long:

Circuit Description:
This DTC will diagnose a motor that is energized longer than expected. This could occur if a wheel speed sensor is faulty, the motor does not turn, the brakes are dragging or the motor wires are crossed.

DTC Will Set When:
DTC 54 can be set only during an ABS stop. If the EBCM/EBTCM commands the rear ABS channel in release for three seconds, a malfunction exists.

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

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Identifies a problem in a wheel speed sensor that may cause the system to be in release too long.
2. Checks for a wheel that may stick or bind because of a mechanical fault.
3. Checks to see if the motor is capable of moving and applying the hydraulic piston for the rear wheels.
4. Ensures that the motor wiring is not crossed.
5. Isolates the malfunction of a "no-apply" situation to either the motor pack or ABS hydraulic modulator.

Diagnostic Aids:
An "intermittent" malfunction is most likely caused by a mechanical part of the system that sticks or binds. The frequency of the malfunction can be checked by using the enhanced diagnostic function of the Tech 1.

Using Tech 1 perform hydraulic test to ensure total brake system is functional.

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.