C1287

CIRCUIT DESCRIPTION
This Diagnostic Trouble Code (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 Diagnostic Trouble Code (DTC) will set when the following conditions are met:
^ The Electronic Brake Control Module (EBCM) detects a short to voltage in the red BRAKE warning indicator control circuit during the three second bulb check.
^ The EBCM detects a short to voltage in the red BRAKE warning indicator control circuit when the red BRAKE warning lamp is commanded ON with a 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 Diagnostic Trouble Code (DTC) stores.
^ ABS remains functional.
^ If the Electronic Brake Control Module (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.

CONDITIONS FOR CLEARING THE DTC:
^ The condition responsible for setting the Diagnostic Trouble Code (DTC) no longer exists and the Scan Tool Clear DTCs function is used.
^ 100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.

DIAGNOSTIC AIDS
The following conditions may cause a malfunction:
^ A poor connection
^ Rubbed-through wire insulation
^ A broken wire inside the insulation
^ Faulty red BRAKE warning indicator control electrical circuit
^ Open red BRAKE warning indicator bulb
^ Open IG FUSE
^ Poor Electronic Brake Control Module (EBCM) connector C1 terminal B5 contact

The parking brake handle may be lifted to verify proper indicator operation and continuity of the red BRAKE warning indicator lamp circuitry.
Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Improperly formed or damaged terminals
^ Poor terminal-to-wiring connections
^ Physical damage to the wiring harness

TEST DESCRIPTION
4. This test checks for an open or high resistance in the brake warning indicator circuit.
5. This test checks for a short to voltage in the brake warning indicator circuit.
9. This test checks for battery voltage at the Junction Block.
10. This test checks for battery voltage at the Instrument Panel Cluster.

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Part 2 Of 2:

DTC C1287 BRAKE WARNING INDICATOR CIRCUIT OPEN OR SHORTED TO VOLTAGE