Brake Fluid Level Switch

The brake fluid level switch, mounted in the master cylinder reservoir, is hardwired to the IPC through a signal circuit and grounded through a separate body ground circuit. The IPC provides a reference voltage to the brake fluid level switch. When the brake fluid level is low, the float drops, allowing the switch to open, sending the reference voltage high. When the brake fluid level is high, the float lifts, closing the switch, providing a ground and pulling the reference voltage low on the signal circuit to the IPC.