C1293

CIRCUIT DESCRIPTION
This DTC is the second portion of DTC C1291 and C1292. If DTCs C1291 or C1292 occurred during the last ignition cycle, DTC C1293 becomes a current malfunction during the next ignition cycle, keeping ABS disabled until a brake switch ON state is seen.

CONDITIONS FOR SETTING THE DTC
DTC C1293 alone indicates DTC C1291 or C1292 occurred previously, but is intermittent, or has been corrected.

ACTION TAKEN WHEN THE DTC SETS
ABS is disabled until the EBCM receives a valid input from the brake switch.

CONDITIONS FOR CLEARING THE DTC
Conditions for the malfunction are no longer present and the scan tool CLEAR DTCs function is used. When a change is seen during an ignition cycle in which DTC C1293 is a current malfunction, DTC C1291 or C1292 will clear itself at the end of the current ignition cycle and ABS will enable itself at the start of the next ignition cycle.

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.

Also, verify proper brake switch operation using the DATA LIST of the scan tool. As the brake is applied, the DATA LIST should display the brake switch ON within one inch of travel.