Lighting fault 2002 c220 CDI

[Philip M]

Hello,
I have been enjoying this forum for about a year now, but until now didn't want to intrude. However my wife's C class has recently developed a lighting fault, and I would like to seek advice.
We usually leave the lightswitch in the auto position and recently noticed the lights were on in broad daylight. The dashboard lights were not on but the headlights were.
I switched the lights off, but they stayed on. The only way to turn them off was to switch the ignition off and remove the key.
The fault is intermittent! Sometimes it works fine for a few minutes, then the lights come on.
I took the car to my local MB specialist, who had the car for 24 hours, charged me almost £90 and said they thought it was the front 'SAM' control module. The cost would be about £300 for the part plus about £80 for fitting. I was surprised that the computer diagnostic was unable to positively identify the defect.
I am sure you will understand that I am reluctant to go ahead at that cost, if it is NOT the SAM unit.
Can anyone give me help on this one, is there a history of SAM units failing? Should I take it to the official MB dealer in Norwich for a second opinion?
Any thoughts from the technical guys?
The car is a 2002 C220CDI and has covered approx 94k miles.
Many thanks,
Philip M

 

[television]

This does sound like the front SAM can you put up the next three numbers after WDB 203---


Pleased that you have joined the forum, and welcome

 

[Philip M]

Hello Malcolm,
Thank you for the instant reply.
The numbers are 006
Hope this is enoughf info.
Philip M

 

[television]

Yes the front N10/1 SAM module does have wiring to the headlamps and headlamp auto leveling and other things.

this should be the fault and the chances are is that water has got in.

I replaced 2 of my SAM units last week through the same fault, though on a 230

 

[duncanh]

I had exactly the same problem with my headlights. It is a 2002 c220cdi estate, They regularly came on irrespective of the switch setting (Off or Auto). This was at about 75k miles. I took it for its first MOT (the day before its third birthday), told the dealer, they found no problem. The lights came on and went off when they drove in and out of the workshop.

They then took it to another site for the MOT, came back and told me that the lights came on in broad daylight and wouldn't go off unless they switched the ignition off and took the key out.

They fixed the problem by fitting a new control unit (I believe it is the unit at the top of the windscreen, not anything to do with the SAM). The problem went away and never recurred.

I don't know what they would charge - it was the last thing I got free on the warranty.

 

[television]

I had exactly the same problem with my headlights. It is a 2002 c220cdi estate, They regularly came on irrespective of the switch setting (Off or Auto). This was at about 75k miles. I took it for its first MOT (the day before its third birthday), told the dealer, they found no problem. The lights came on and went off when they drove in and out of the workshop.

They then took it to another site for the MOT, came back and told me that the lights came on in broad daylight and wouldn't go off unless they switched the ignition off and took the key out.



They fixed the problem by fitting a new control unit (I believe it is the unit at the top of the windscreen, not anything to do with the SAM). The problem went away and never recurred.

I don't know what they would charge - it was the last thing I got free on the warranty.

Yes the overhead control panels do give battery drain faults among other things,,its often that you just have to change things to find the leak path as all of the ECU's are inter connected.

Interesting in years to come and the stocking of all of these things