Brake Warning Indicator

The IPC  uses 3 basic messaged inputs to control the brake warning indicator. The first 2 messages are the parking brake position switch and the brake fluid level switch sent from the BCM  . The third is the for EBD  and low brake booster vacuum or vacuum sensor fault messages sent from the ABS module.

The parking brake position switch is hardwired to the BCM  through a single signal circuit, while using a separate ground to control the input. The brake fluid level switch is hardwired to the BCM  through separate signal and return circuits to control the input.

The BCM  provides a reference voltage to both the parking brake position switch and the brake fluid level switch. When the parking brake is applied, the parking brake position switch closes to ground, pulling the reference voltage on the parking brake signal circuit low. When a low brake fluid level condition exists, the brake fluid level switch closes to ground pulling the reference voltage on the brake fluid level signal circuit low. When the brake fluid level switch is disconnected, the reference voltage on the brake fluid level signal circuit is sent high. When the BCM  detects the parking brake is applied, a low brake fluid level condition exists or the brake fluid level switch is disconnected, the BCM  sends the IPC  a brake warning indicator request.

When the ABS module detects a base brake system concern or other ABS related concerns that affect the EBD  function or brake booster vacuum, the ABS module sends a brake (red) warning indicator request to the IPC  to illuminate the brake warning indicator and the ABS warning indicator.