A057

Fig. 497 Code 57: Left Front Motor Circuit Shorted To Ground:

DTC A057 Left Front Motor Circuit Shorted To Ground:

Circuit Description:
This DTC identifies a motor circuit that is shorted to ground. This malfunction will not allow the motor to be controlled at the commanded current rate or will cause the driver circuit to allow current directly to ground.

Failure Condition:
DTC AO57 can be set anytime. If the EBCM detects an out of range voltage on either of the left front motor circuits (indicating a circuit shorted to ground), a malfunction exists.

Action Taken:
A DTC AO57 is stored, ABS is disabled and the "ABS" indicator is turned on.

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

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.