Warning Lamp Circuit Diagnosis

Stop Lamp Warning Circuit Diagnosis

Steps 1-18 (continue):

Steps 18 (continued) - 33:

Steps 34 & 35:

Test Description
The number(s) refer to step(s) on the diagnostic table.
1. When the ignition is turned ON, the brake warning lamp should initially illuminate and then dim for ABS equipped vehicles. This is done as a bulb check. On vehicles that are not equipped with ABS, the brake warning lamp should only illuminate when either the brake fluid reservoir is low or the parking brake is applied.
7. The brake fluid level switch is a normally open switch. If the brake warning lamp is off after disconnecting the switch, the brake fluid level switch is stuck closed.
9. If the brake warning lamp is still on after disconnecting the parking brake switch, there is a short to ground in the wire to the parking brake switch.
12. If the other checks have been properly performed and the brake warning lamp is off after disconnecting the Electronic Brake Control Module (EBCM) 31 connector, the EBCM is faulty.
19. If the brake warning lamp does not operate while performing any of the functions, the fault should be in the ignition feed to the circuit.
24. This step determines if the problem is in the ignition feed to the circuit or in the instrument cluster.
30. The brake warning lamp should illuminate when jumping the parking brake connector to ground.
32. If the brake warning lamp is on after jumping the brake fluid level switch terminals, the switch is faulty.