C1294

DTC C1294: Brake Lamp Switch Circuit Always Active (Part 1 Of 2):

DTC C1294: Brake Lamp Switch Circuit Always Active (Part 2 Of 2):

DTC C1294 Schematic:

Circuit Description
This DTC is run to determine the proper operation of the stoplamp switch, which detects that the stoplamp switch is closed at all times or there is a short to voltage in the stoplamp switch input circuit to the Electronic Brake Control Module (EBCM).

Conditions for Setting the DTC
This DTC will set when the following conditions are met:
^ This DTC can be set if the vehicle speed reaches at least 40 km/h (25 mph).
^ The EBCM detects the stoplamp switch was always closed during two consecutive drive cycles.

Action Taken When the DTC Sets
A malfunction DTC is stored, however ABS is not disabled.

Conditions for Clearing the DTC
^ Conditions for the malfunction are no longer present and the Tech 2 scan tool Clear DTC Information function is used.
^ One hundred drive cycles have passed with no malfunctions detected.

Diagnostic Aids
The following list contains items that need to be inspected when diagnosing this system:
^ Stoplamp switch out-of-adjustment.
^ Faulty stoplamp switch (contacts always closed).
^ Stoplamp switch input circuit shorted to battery (CKT 20A/B/C/D/G).
An intermittent malfunction is most likely caused by a rubbed through wire insulation. Any circuitry that is suspected of causing the intermittent complaint should be thoroughly checked for improper mating, improperly formed or damaged terminals, or physical damage to the wiring harness.

The frequency of the malfunction can be checked by using the Enhanced Diagnostic function of the Tech 2 scan tool, as described in Enhanced Diagnostics found.


Test Description
Numbers below refer to numbers on the diagnostic table.
2. Checks for closed stoplamp switch contacts.
5. Checks for a short to voltage in CKT 20A/B/C/D/G.