DTC 78

Code 78: Right Front Solenoid Circuit Open Or Shorted To Ground.:

DTC 78 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 EBCM/EBTCM and the solenoid. An open will not allow proper ABS operation, but the short to ground simply turns "ON" the solenoid. A path for base brakes is still allowed once the motor re-homes and the check valve is lifted off its seat during key "ON" initialization.

DTC Will Set When:
DTC 78 can be set only when the solenoid is commanded "OFF." A malfunction exists if the EBCM/EBTCM detects low voltage in the right front solenoid control circuit.

Action Taken:
A malfunction DTC is stored, ABS is disabled and the ABS indicator lamp is turned "ON."

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks for a short to ground in the control circuitry of the solenoid.
2. Checks for an open in the control circuit of the solenoid.
3. Checks for a short to ground in the solenoid.
4. Checks for an open in the battery feed circuit of the solenoid.
5. Checks for proper resistance value of the solenoid.
6. Ensures malfunction was not due to physical damage of the circuitry.

Diagnostic Aids:
An "intermittent" malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.

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.