Metro L4-079 1.3L VIN 9 TBI (1995)
Brake Warning Indicator: Description and Operation
Circuit Operation
The "BRAKE" Indicator, when lit, alerts the driver that the Parking Brake is engaged or that there is an insufficient amount of brake fluid in the Master
Cylinder Reservoir. If the vehicle is equipped with the Antilock Brake System (ABS), the Electronic Brake Control Module (EBCM) will turn on the
"BRAKE" Indicator along with the "ABS" Indicator to alert the driver that there is a malfunction with the ABS which has affected the vehicle's base
braking system. The "BRAKE" Indicator will also light when the Ignition Switch is turned to the Bulb Test position.
Voltage to the "BRAKE" Indicator is provided through the 10 Fuse. If the Parking Brake is engaged, then the Parking Brake Switch is closed. Since the
Parking Brake Switch is case grounded, a ground input is received by the Daytime Running Lamps (DRL) Control Module. The DRL Control Module,
in turn, provides ground for the "BRAKE" Indicator. With both power and ground applied to the "BRAKE" Indicator, it lights. If the brake fluid level is
low enough, then the Brake Fluid Level Switch, located within the Master Cylinder Reservoir, is closed. Since the Brake Fluid Level Switch is grounded
at G201, the "BRAKE" Indicator lights whenever there is a low, brake fluid condition.
If the vehicle is equipped with ABS and the "BRAKE" and "ABS" Indicators are lit simultaneously, then a ground has been provided to the "BRAKE"
Indicator by the EBCM. This alerts the driver that a problem exists within the ABS which is affecting the action of the base braking system.
The Bulb Test Check operation of the "BRAKE" Indicator occurs only when the Ignition Switch is turned to the "BULB TEST" position. When the
Ignition Switch is turned to the "BULB TEST" position, ground is provided through the Ignition Switch to G203. With both power and ground applied
to the "BRAKE" indicator, the "BRAKE" Indicator lights.
