C1287

DTC C1287: Red BRAKE Warning Indicator Circuit Open Or Shorted To Voltage (Part 1 Of 3):

DTC C1287: Red BRAKE Warning Indicator Circuit Open Or Shorted To Voltage (Part 2 Of 3):

DTC C1287: Red BRAKE Warning Indicator Circuit Open Or Shorted To Voltage (Part 3 Of 3):

DTC C1287 Schematic:

Circuit Description
This DTC identifies an open or short to voltage between the Electronic Brake Control Module (EBCM) and the red BRAKE warning indicator, or an open driver that does not allow the red BRAKE warning indicator to be illuminated by the EBCM. This will only occur if an ABS malfunction is detected that may degrade base brake operation. Because the EBCM is not the only device controlling the red BRAKE warning indicator (parking brake and the brake fluid level switch may also turn on the red BRAKE warning indicator), a short to ground in this circuit cannot be detected.

Conditions for Setting the DTC
This DTC will set when the following conditions are met:
^ The EBCM detects a short to battery in the red BRAKE warning indicator control circuit during the three second bulb check.
^ The EBCM detects a short to battery in the red BRAKE warning indicator control circuit when the red BRAKE warning lamp is commanded ON with a Tech 2 scan tool (output for the red BRAKE warning lamp control circuit is greater than 3.43 volts).
^ The EBCM detects an open or high resistance in the red BRAKE warning indicator control circuit at above 5 km/h (3 mph) with red BRAKE warning lamp turned OFF (output for the red BRAKE warning lamp control circuit is between 3.35 volts and 5.23 volts).

Action Taken When the DTC Sets
A malfunction DTC is stored and the ABS is not disabled. However, if the EBCM commands the red BRAKE warning indicator ON due to an ABS malfunction that may degrade base brake operation and cannot do so, the amber ABS indicator lamp will flash to indicate the serious nature of the problem.



Diagnostic Aids
The following list contains items that need to be inspected when diagnosing this system:
^ Faulty red BRAKE warning indicator control electrical circuit (short to battery in CKT 33AIB/C/D).
^ Open red BRAKE warning indicator bulb.
^ Open IG FUSE.
^ Poor EBCM connector C1 terminal B5 contact
^ Faulty EBCM.

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 is most likely checked by using the Enhanced Diagnostic function of the Tech 2 scan tool, as described in Enhanced Diagnostics. The parking brake handle may be lifted to verify proper indicator operation and continuity of the red BRAKE warning indicator lamp circuitry.

Inspect the following harness connectors 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 before component replacement:
^ EBCM connector C1.
^ I/P cluster C2 and C3.

Test Description
Numbers below refer to numbers on the diagnostic table.
2. Checks for a short to ground in CKT 33A/B/C/D.
3. Checks if the red BRAKE warning indicator turns ON.
10. Checks for an open in CKT 33A/B/C/D.