Normal Operation

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

The red brake warning indicator is located in the instrument cluster and illuminates when the brake fluid in the brake master cylinder reservoir is below a specific level, when the parking brake is engaged, or when there is a failure with the anti-lock brake system (ABS) electronic brake force distribution (EBD) system (the yellow ABS warning indicator will also illuminate). The instrument cluster receives a ground input on circuit 1309 (RD/YE) when the parking brake has been applied through circuit 1205 (BK), turning on the brake warning indicator. The smart junction box (SJB) provides a voltage reference signal to the brake fluid level switch through circuit 1305 (DB) and back to the SJB on circuit 128 (VT/YE). When the brake fluid level is low, the brake fluid level switch closes to circuit 128 (VT/YE). If the voltage reference signal the SJB is sending to the brake fluid level switch drops to zero, then the SJB sends a standard corporate protocol (SCP) message to the instrument cluster to turn on the brake warning indicator.