Operation CHARM: Car repair manuals for everyone.

Brake Warning System

CIRCUIT OPERATION
The brake warning indicator on the instrument cluster illuminates under the following conditions:
^ Ignition in the start position
^ The park brake is set
^ The master cylinder brake fluid level is low
^ The electronic brake control module applies ground to the instrument cluster

These conditions are explained in detail below.

PARK BRAKE
The park brake switch closes when the park brake is set. Ground is applied to the DRL module circuit 1134 and from the DRL module circuit 33 to the instrument cluster. The brake indicator illuminates.

BRAKE FLUID LEVEL
When the brake fluid level in the master cylinder is low, the brake fluid level indicator sensor closes. Ground is applied through the sensor and circuit 33 to the instrument cluster. The brake indicator illuminates.

EBCM
The brake indicator indicator is also controlled by the ABS system through the Class 2 serial data line. The Electronic Brake Control Module (EBCM) applies ground to circuit 33 to illuminate the brake indicator. The indicator warns the customer that problem exists in the ABS system.

CIRCUIT OPERATION
The brake warning indicator on the instrument cluster illuminates under the following conditions:
^ Ignition in the start position
^ The park brake is set
^ The master cylinder brake fluid level is low

These conditions are explained in detail below.

PARK BRAKE
The park brake switch closes when the park brake is set. Ground is applied to the DRL module circuit 1134 and from the DRL module circuit 33 to the instrument cluster. The brake indicator illuminates.

BRAKE FLUID LEVEL
When the brake fluid level in the master cylinder is low, the brake fluid level indicator sensor closes. Ground is applied through the sensor and circuit 33 to the instrument cluster. The brake indicator illuminates.