brake lights

Faulty pedal sensor may be? You have ABS I think? Go here:

Andrew

pipefitter wrote:

OK, it made a hyperlink after all but linked to the wrong thing, scroll up from that link position to the error codes, the one you want says "Faulty pedal sensor: shorted to ground or supply".

Cheers

Andrew

Andrew McKenna wrote:

Also possible that the relay controlling the lamps is cooked. Not sure about the 850, but on the 7 series, it's behind the fuse panel, and is big, round and red...and expensive.

RS

That's the lamp failure sensor which controls the warning light on the dash. I've seen them fail a few times and each time I was able to fix it by touching up the solder joints on the circuit board inside.

Common on the 850 is the brake light switch. And the failure sensor is located in the left frame rail inside the trunk, about 1 foot from the rear of the car.