Brake light switch
Together with the signal from the brake pressure sensor, braking operations are detected. Two Hall effect sensors as switches are installed in the brake light switch: the brake light switch and the brake light test switch (redundancy for safety reasons). The signals indicate whether the brake pedal has been pressed. The data interchange is digital.
| Item | Explanation |
|---|---|
| 1 | Brake light switch |
| 2 | 4-pin plug connection |
The two redundant signals from the brake light switch are read in by the Car Access System (CAS). The CAS relays the signals to systems such as the Dynamic Stability Control (DSC) and for the engine-management control unit via the bus system. A signal from the brake-light switch is still hard-wired to the footwell module (FRM).
Depending on the vehicle, the brake light switch from the Front Electronic Module (FEM) is read in. Observe the wiring diagrams in the diagnosis!