DTC 64

Code 64: Rear ABS Motor Circuit Open.:

DTC 64 Rear ABS Motor Circuit Open:

Circuit Description:
This DTC identifies an ABS motor that cannot be energized due to an open in its circuitry. This malfunction will not allow proper ABS operation.

DTC Will Set When:
DTC 64 can be set only when the ABS motor is commanded "OFF." If the EBCM detects an out of range voltage on either of the rear axle 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. The amber ABS warning lamp is turned

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This 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 of 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.