Antilock Brake System

CIRCUIT DIAGRAM





INSPECTION PROCEDURE

CIRCUIT DESCRIPTION:
These DTCs identify a motor that cannot be energized due to an open in its circuitry.

FAILURE CONDITION:
DTCs 56, 61 and 64 can be set only when the motor is commanded off. If the Electronic Brake Control Module (EBCM) detects an out of range voltage on either of the motor circuits (indicating an open circuit), a malfunction exists.

DIAGNOSTIC AIDS:
Using TECH-1, select manual control function and exercise motor movement of affected channel in both directions while applying light pressure on the brake pedal.
If erratic or "jumpy" brake pedal movement is detected while performing an "apply" or "release" function of the motor, an intermittent malfunction may be indicated.
An "intermittent" malfunction may be caused by a poor connection, rubber through wire insulation or a wire that is broken inside the insulation.
If the malfunction is not current, wiggle the wires of the affected channel and check if the DTC resets.
This will help to pinpoint an intermittent malfunction in the motor circuitry or connections.
The frequency of the malfunction can be checked by using the enhanced diagnostic function of the TECH-1 as described in "TECH-1 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.