DTC A078: Right Front Solenoid Circuit Open/Shorted to Ground

RIGHT FRONT SOLENOID CIRCUIT OPEN OR SHORTED TO GROUND





Circuit Description
This DTC identifies a solenoid that cannot be energized due to an open in its circuitry, or a solenoid that is always energized due to a short to ground in its circuitry between the driver and the solenoid. An open will prevent proper ABS operation, but the short to ground simply turns the solenoid on. A path for base brakes is still allowed once the motor rehomes and the check ball is lifted off its seat during initialization.

Diagnosis
This test detects a short to ground or open in the right front solenoid circuitry. The open will prevent proper ABS operation, but the short to ground simply turns on the solenoid. The system can not differentiate between the two faults.

Cause(s)
- The solenoid connector is open.
- There is a short to ground in the solenoid control circuitry.
- There is an open in the solenoid control circuitry.
- There is an open in the solenoid or battery circuit.
- The solenoid is defective (high/infinite coil resistance).
- The electronic brake control module (EBCM) is faulty.

Fail Action
This is a critical operational fault. The ABS is disabled and the ABS warning lamp is turned on. The system commands a rehome to ensure that all motors are in the home position.

Test Description
The number(s) below refer to step(s) on the diagnostic table.
1. This checks for a short to ground in the control circuitry of the solenoid.
2. This checks for an open in the control circuit of the solenoid.
3. This step checks the solenoid coil for proper resistance.
4. This step checks for an open in the solenoid voltage supply circuit.
5. This step checks for a possible intermittent malfunction in the solenoid circuitry due to a poor terminal contact.

Diagnostic Aids
An intermittent malfunction may be caused by a poor connection, wire insulation that has been rubbed through, or a wire that is broken inside the insulation.
Check the frequency of the malfunction by using the enhanced diagnostic feature of the scan tool as described in "Scan Tool Diagnostics." Scan Tool Diagnostics
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.





DTC A078 - Right Front Solenoid Circuit Open or Shorted to Ground