A066

Fig. 504 Code 66: Rear Motor Circuit Shorted To Battery:

DTC A066 Rear Motor Circuit Shorted To Battery:

Circuit Description:
This DTC identifies a motor circuit that is shorted to battery or a motor that has low or no resistance. This malfunction will not allow the motor to be controlled at the commanded current rate or will cause the motor to turn in the opposite direction or not at all.

Failure Condition:
DTC AO66 can he set only when the motor is commanded off. If the EBCM detects an out of range voltage on either of the rear motor circuits (indicating a circuit shorted to battery or a motor shorted), a malfunction exists.

Action Taken:
A DTC A066 is stored, ABS is disabled and the "ABS" indicator is turned on or will flash.

Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step checks for a short to voltage in the motor high circuitry.
2. This step checks for a short to voltage in the motor low circuitry.
3. This step checks for a motor that is internally shorted.

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, 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.