The brake indicator in the instrument cluster serves to alert the operator to problems in the vehicle's braking system. With the ignition switch in the RUN or START position, voltage flows to the instrument cluster from the PNK (39) wire from GAUGES fuse 4. The brake indicator lamp is illuminated whenever the TAN/WHT (33) wire from the instrument cluster is grounded.
The BRAKE indicator lamp is tested whenever the vehicle's engine starts. Placing the ignition switch in the START position connects a ground path from the ignition switch to ground G200 through the BLK (150) wire. With this ground connection, current flows through the TAN/WHT (33) wire to the daytime running lamp (DRL) module. The DRL control module logic allows the current to complete the circuit, and the brake indicator lamp is illuminated. Placing the ignition switch in the RUN position break the connection and the lamp goes out. The BRAKE indicator lamp also illuminates if you apply the parking brake while the ignition switch is in the RUN or the START position. This alerts the operator to release the parking brake. The parking brake warning switch is mechanically grounded. The switch contacts close when you apply the parking brake, grounding the TAN/WHT (33) wire through the daytime running lamp control module. The DRL control module logic prevents the operation of the daytime running lamps while the parking brake is engaged. The daytime running lamps also will not operate if either of the following conditions are present:
| • | Lamp operation by the brake pressure differential switch |
| • | Lamp operation by the electronic brake control module |
| • | Park brake warning switch depressed |
The brake pressure warning switch closes its contacts when conditions in the hydraulic brake system are abnormal. This grounds the TAN/WHT (33) wire through the BLK (150) wire to ground G105. See antilock brake system for detailed information about the function of this switch.
The electronic brake control module also grounds TAN/WHT (33) circuit if there are abnormal conditions in the antilock brake system (ABS). The BRAKE indicator lamp and the antilock brakes warning indicator lamp both light for ABS failures. See antilock brake system for detailed information about the operation of the antilock brake system.
