C1187

PINPOINT TEST 8: DTC C1187: BRAKE FLUID LEVEL INPUT CIRCUIT OPEN

Normal Operation

The brake fluid level switch is a normally open switch attached to a flotation device in the master cylinder reservoir. The anti-lock brake system (ABS) module sends out a voltage along circuit (Y/GY) which returns to the module along circuit (GY/V). When the brake fluid is at the correct level, the switch remains open and the ABS module detects a returning voltage. When the fluid level falls below a predetermined level, the switch closes and connects circuit (GY/V) and circuit (Y/GY) to ground circuit (B/Y). The ABS module will no longer detect the returning voltage and sends a signal to the instrument cluster along circuit (G/V) and the instrument cluster illuminates the red brake warning indicator.

Possible Causes
- Wiring, terminals or connectors
- Brake Fluid Level Switch (integral to the brake fluid reservoir)
- ABS module

CAUTION:Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.

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