I have a 95 sl500 the tail light warning light on dash comes on when I start the car. It has nothing to do with the lights because they are off and the brakes and turn signals are off as well. Is this simply a sensor malfunction or does it mean something else. I would prefer to simply unplug the sensor rather than spend the money to trace the cause. How wouldI go about unplugging the sensor?

 

possilbly the wrong bulbs are installed. must check the pins on the socket of the bulbs they might be offset or straight. or taillight assembly faulty.

 

I would suggest you have a bulb out.
Have you double checked (all bulbs and also intensity. sometimes functions have more than one bulb) they are all working including the brake lights?
The sensor is usually (I don't know about w140) part of the PSE unit which is a multifunction "black box" that works the door latches and security as well as bulb monitoring and interior light.
I guess it is possible to bypass the warning system but if you are not bothered in having a bulb monitoring function why not just ignore the warning!
Stuart