Brake Light Switch Signal

Brake-light/brake-test switches

Two switches are fitted on the brake pedal which supply the following signals:

S_BLS (Brake-Light Switch)
S_BLTS (Brake-Light Test Switch)
The DME control module evaluates the signals for the purpose of registering brake operation.

Function

Model series E38, E39, E46, E53, E6x, E8x:
The brake-light switch connects to ground (B-), the brake-light test switch connects to B+.
Model series E36/7 (Z3):
The brake-light switch and the brake-light test switch connect to B+.

Both signals are checked for plausibility.

The following tables show (depending on the model series) how the status of the brake-light-switch/brake-light test switch performs:











Troubleshooting

If the signals are not plausible in relation to one another, a fault code is stored in the DME control module. Cruise control is deactivated as a result of this fault memory entry.