Brake Warning Indicator

Fig 1: Identifying Brake Warning System Block Diagram

Courtesy of GENERAL MOTORS COMPANY

The instrument cluster turns the brake warning indicator ON when the following occurs:

• The instrument cluster performs the bulb check. The brake warning indicator illuminates for 5 seconds.
• When the EBCM detects a too low brake fluid level it sets a DTC and sends a serial data message to the instrument cluster, which will illuminate.

Electronic brake control module (EBCM) monitors the brake fluid level in the brake fluid reservoir. When the fluid within the brake fluid reservoir is below the MIN level, contacts within the brake fluid level switch closes causing the voltage within the signal circuit to drop. The electronic brake control module (EBCM) will detect the voltage drop and will send a serial data message to the instrument cluster commanding the brake warning indicator to illuminate.