DTC 56

DTC 56 Left Front ABS Motor Circuit Open:

Circuit Description:
This DTC identifies a motor that cannot be energized due to an open in its circuitry.

DTC Will Set When:
DTC 56 can be set only when the motor is commanded "OFF." If the EBCM detects an out of range voltage on either of the left front ABS motor circuits indicating an open circuit, a malfunction exists.

Action Taken:
An open ABS motor will not activate when requested. 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. Checks for proper resistance of the ABS motor.
2. Checks for an open in the ABS motor "HIGH" circuitry.
3. Checks for an open in the ABS motor "LOW" circuitry.
4. Ensures malfunction was not due to poor terminal contact.

Diagnostic Aids:
Using Tech 1, select manual control function, and exercise ABS 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 ABS motor, an intermittent malfunction may be indicated.

An "Intermittent" malfunction may be caused by a poor connection, rubbed 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.

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.