jmgw123

Hello everyone,
Im Johnny and Im from the Caribbean. I imported a 2001 S500 from the USA with an issue I can't seem to solve. Here it is; As soon as I start the car the break lights come on and it never goes out until I turn the car off. I checked everything I know but the issue still persist.
I wish I can get some help here.
Thanks in advance
Johnny

MJ50

moved to W220 forum...

bamberger_1

Replace the brake light switch behind the brake pedal. Relatively cheap and 80-90% chance to solve the problem. But watch out to pull the (white??) pin of the new switch as far as it goes, so the new switch calibrates itself to the pedal travel

Astro14

If it's not the switch, then the problem is likely in your rear SAM.

Tucked under the passenger side rear seat is a Signal Acquisition Module. If water gets in there (which is not uncommon) it can cause corrosion, shorts, and failures of that module, which affects quite a few systems, including brake lights.

Change the switch, as suggested, but make certain that it's clean and dry under that right rear seat as well as under the front passenger footwell carpet...

jmgw123

Changed the switch. I also tested the new and the old switch on another S class and they both worked.

jmgw123

I switched the SAM with that of another S class. Nothing changed. Any other possibilities?????

vinflouen

Replace it.
Worked fine for me!
There are sellers on Amazon who sell only one side as well.

jmgw123

Thanks for ur reply Vinflouen. Did u have an issue with the brake lights? also, what is it that they sell on amazon that I can get one side of? if its the lights themselves< I doubt they r bad cuz I switched those also with another s class that I have.

kraut56

Scan with SDS. Anything else is just throwing parts at it.

tusabes

are you sure it’s the brake lights that are on (with the third center brake light too) or just the running lights (no center brake light on)

if it’s just the running lights this can be a daytime running lights setting

jmgw123

Center brake lights also. That’s for sure. Not running lights.

jmgw123

Any info on the possibility of the shifter being part of this problem with the brake light. I had someone scan the car and he told me the problem is the shifter. The thing about that is that the shifter is coded and that’s gonna cost about $1300. Don’t wonna spend that then find out it’s not the cause.