Functional description
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: Brake light switch output conducts and brake light test switch blocks.
| 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 read in by the Car Access System (CAS). The CAS forwards the signals on the bus system, e.g. for the engine control system.
The signals from the brake light switch are hard-wired and branched off for the following systems:
- Footwell module (FRM) for reversing light
- Dynamic Stability Control (DSC) for brake intervention
Included as of F1x: No longer hard-wired, rather a bus signal to the DSC.