C1291

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(Part 2 Of 2):

CIRCUIT DESCRIPTION
This DTC is used to detect an open brake switch in the non-ABS mode. The EBCM looks for a deceleration rate that would indicate braking action and verifies this assumption by requiring several repeats of this detection method. In each case, ABS will not be available since no brake switch is seen.

CONDITIONS FOR SETTING THE DTC
DTC C1291 can be set if three deceleration cycles occur with the brake switch OFF.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS is disabled, and the ABS indicator lamp is turned ON.

CONDITIONS FOR CLEARING THE DTC
Conditions for the malfunction are no longer present and the scan tool CLEAR DTCs function is used.One hundred ignition switch key cycles have passed with no malfunctions detected.

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 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.