BRAKE Warning Indicator

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

The parking brake switch and the brake fluid level switch (part of the master cylinder) are hardwired to the instrument cluster (IC). The BRAKE warning indicator uses 3 inputs. The first input is provided by the parking brake switch, and when applied, provides a ground signal to the instrument cluster (IC), illuminating the BRAKE warning indicator. The second input is controlled by the brake fluid level switch. When the brake fluid level is low, the brake fluid level switch closes and provides a ground to the instrument cluster (IC) to illuminate the BRAKE warning indicator. The third input uses the base brake system. If a base brake system concern occurs, the ABS module provides a brake signal to the instrument cluster (IC) over the HS-CAN, to illuminate the BRAKE warning indicator. If a loss of communication from the ABS module to the instrument cluster (IC) occurs, the BRAKE warning indicator illuminates.