Brake Light Switch: Description and Operation

The transmission control module and shift lock relay receive information from the brake light switch.

When the brake pedal is depressed, the brake light switch is activated and sends information to pin 26 of the transmission control module. As a result, the lock-up is disengaged if engine speed is less than 2000 RPM.

Current (B+ circuit) is applied to pin 26 on activation of the brake light switch.

On cars with a SHIFT-LOCK function, the selector lever is mechanically locked in the P position when the engine is started. Depressing the brake pedal causes the shift lock relay to be checked and mechanical locking of the selector lever is then released.