ABS - With Traction Control

CIRCUIT DESCRIPTION
This DTC identifies a brake solenoid valve that cannot be energized. The malfunction may be due to an open in its circuitry, or is always energized due to a short to ground in its circuitry between the driver and the brake solenoid valve. An open will not allow proper ABS operation, but the short to ground simply turns on the brake solenoid valve. A path for base brakes is still allowed once the motor re-homes and the check ball is lifted off its seat during key to RUN initialization.

CONDITIONS FOR SETTING THE DTC
DTC C1278 can be set only when the solenoid is commanded off while the ABS/ETS relay is enabled. If the EBCM/EBTCM detects the right front brake solenoid valve control circuit voltage is out of specification, a malfunction exists.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, and ABS/ETS is disabled. The amber ABS warning indicator is turned on.

CONDITIONS FOR CLEARING DTC
Condition for DTC is no longer present and the scan tool (CLEAR DTCs) function is used, or 100 drive cycles have passed with no DTC(s) detected.

DIAGNOSTIC AIDS
An intermittent malfunction may be 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 Scan Tool. 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.

NOTE: J 39200 test leads must be zeroed prior to making any resistance measurements. Refer to J 39200 user's manual.