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Brake light switch

Two Hall effect sensors as switches are installed in the brake light switch:

The signals indicate whether the brake pedal has been pressed. The data interchange is digital.

The brake-light switch has no moving parts and works as a non-contact switch. A change in the switching state is achieved by removing or applying a ferromagnetic trigger element to the brake pedal.

Switching mode with brake not applied:

Fig 1: Identifying Brake Pedal Components
G09871711Courtesy of BMW OF NORTH AMERICA, INC.
Index Explanation
1 Brake light switch
2 4-pin plug connection
3 Brake pedal pressed
4 Brake pedal not pressed

The two redundant signals from the brake light switch are forwarded for example to the Digital Engine Electronics (DME).

The signals from the brake light switch are also evaluated for the following functions: