Lamp Sensor Malfunction

[Ethan]

Car a 2002 C240, get a LIGHT SENSOR VISIT WORKSHOP malfunction every so often. Anyone have a similar experience?

If a bulb goes bad this car will tell you exactly which bulb so I don't think this warning is a symptom of a bulb/socket problem, and I experimented with new reverse and brake light bulbs.

Owners manual seems to suggest Lamp Sensor involves the Automatic position and settings on the headlight switch, but it isn't explicit.

Previous work at a dealership had the tech needing to adjust a brake pedal switch in the footwell a few times before geting it right. That was a ESP/BAS wiring harness repair.

Any opinions, guesses?

[ILUVMILS]

Have your dealer check for fault codes. The light sensor probably needs to be replaced. No big deal.

[stevebfl]

Looking around the only reference I saw was the Rain/Light sensor attached to the OCP (overhead control panel). Not sure how many functions it has. I know the interval wiper works off it. I suppose some amount of light control must also be derived from it. Need to read the fault codes.

[Ethan]

thank you both for the great response.

When I took the car in for the problem a few weeks back, because the problem is intermittent and would seemingly reset itself and read NO MALFUNCTION after a restart, the service writer told me there was NO way to check for stored codes.

Also when I took the car in a few weeks back, because the malfunction would display as I was getting out of the car, due to habit I had turned the ignition off before reading the malfunction explantion with either the reset button or steering wheel tab. So I went into the dealership thinking their scanner would retrieve previous malfunctions, but the dealership said that wasn't possible.

[manny]

Does your rain-sensing wiper work WHILE the fault is diplayed ?

[Ethan]

I'll try to get the Malfunction reading and then test the wipers. I never would have guessed that combination.

Thanks

[ILUVMILS]

[QUOTE=Ethan]thank you both for the great response.

When I took the car in for the problem a few weeks back, because the problem is intermittent and would seemingly reset itself and read NO MALFUNCTION after a restart, the service writer told me there was NO way to check for stored codes.

Did they even run a "quick-test" to check for codes? The front dome lamp, or Overhead Control Panel (OCP) is capable of storing intermittent fault codes relating to the Rain/Light sensor. Go back and ask the service advisor to have it checked!

[Ethan]

I don't think they ran any quick test to chk on the light sensor.

I thought you professional mechanics at this site would find the following link interesting.

go to www.mbklasse.com

do a search under the following "R171 SLK rain sensor part numbers"

it has pictures and info on the new SLK rain/light sensor