Brake Fluid Level Sensor/Switch: Description and Operation

CIRCUIT OPERATION

The brake system warning light goes on to alert the driver that the parking brake is applied or that the brake fluid is low. It also lights as a bulb test when the engine is cranked.

Parking Brake Switch
With the starter switch in ON or START, battery voltage is applied through the CB-11 METER fuse to the brake system warning light. When the parking brake is applied, the parking brake switch closes and provides a ground for the light. The brake system warning light goes on to remind the driver that the parking brake is applied.

Brake Fluid Level Switch
With the starter switch in ON or START, battery voltage is applied through the CB-11 METER fuse to the brake system warning light. If the brake fluid is low, the brake fluid level switch closes and provides a ground for the light. The brake system warning light goes on to warn the driver of low brake fluid level in the brake master cylinder. (Note: check brake pad wear before adding fluid.)

Bulb Check
With the starter switch in START, the brake system warning light is turned on for bulb check. During bulb check, the light is grounded through the alternator. See Indicators for further details.