DTC 77

Fig. 385 Code 77: Left Front Solenoid Circuit Shorted To Ground Or Driver Open:

DTC 77 Left Front Solenoid Circuit Shorted To Ground Or Driver Open:

Circuit Description:
This DTC identifies a solenoid that cannot be energized due to an open in its driver circuitry, or a short to ground between the solenoid driver and the solenoid. These malfunctions can affect ABS operation since the flow of brake fluid to the wheel cylinder cannot be stopped, making ABS operation for that channel impossible.

DTC Will Set When:
DTC 77 can be set only when the solenoid is commanded "ON." A malfunction exists if the EBCM detects the left front solenoid control circuit voltage is out of specification.

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

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks for a solenoid that is internally shorted to ground.
2. Checks for a solenoid that is not within proper resistance value.
3. Indicates if a short to ground exists in the solenoid control circuitry.
4. 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.