I have a 2002 C240 sedan.

The right rear light came on saying that the bulb had blown and that the substitute light was on (two faults).

Now, I replaced the bulb, the most top bulb on the light rack. Tested it out and everything worked. The fault did not go away. 2 weeks later, the faults are still there. I checked the bulb again tonight pulling both light racks and everything is working (the best I can tell).

Any ideas on how to get these faults to go away? I used an OEM MB bulb.

Eric
www.installuniversity.com

Blown bulb on '02 C

 

hi wizkid, i had the same thing happen to me not long ago, it drove me nuts, all the bulbs were fine, everything worked as best i could tell, but that stupid light in the dash stayed on. i took some 400 grit sandpaper to the contacts on the bulbs, shined it up a bit, put it back together, the light went off a day or so later and hasn't been back on since, i don't know if i wasn't getting a good enough connection or what, a little grease on things may help keep it connected ......later

 

I had similar problem....the fault message came on even though the light was working. I replaced the light anyway and it worked for a while...then the fault message started coming and going, even though the light was working. The dealer replaced the sending unit to make it go away permanently. Then it started happening with the left side! Then the dealer replaced the whole light assembly/carrier and that worked. No problems since (about 18 months ago). I think 13benz fix is a good start.

 

Hmmm

A couple of days ago I got a similar problem - "FR. LEFT MARKER - CHECK BULB" (or something like it). The bulb is fine and everything works - but the malfunction message! This morning the message disapeared but I got it back during lunch

Will try to clean up contacts... Hope that helps...

 

Show me a 203 that DOESN'T have bulb problems.... There are a myriad of updates for this. First replace any and all bulbs in the rear. ALL of them. Now install the "taillamp wiring harness update". There is one for each side. Its a harness that goes between the cars wiring and the taillamp, very simple and self explanatory.
For the front turn signals, there are updated bulb sockets and wiring harnesses for those, the install is a little more involved, and you may need a special and incredibly expensive tool for this. Mine was $40.00 and its just a piece of metal with a handle on it. You remove the pin one wire from the headlamp connector, and plug it in to a new connector for the turn signal, ground the other wire on a nearby ground screw and install the new socket. This hardwires the bulb to the wiring, eliminating the troublesome contacts from the headlamp housing to the bulb socket.
Lastly, mercedes recently released a wiring update for the license plate bulbs. Its similar to the taillamp update.

 

Thanks!! I will call them and get the parts on order for the tail lamp wiring harness update. I will get that ordered ASAP and get it up on my website.

Eric
www.installuniversity.com

 

Mine. Its 2 years old and is an 03 C320. But would be happy to include the improvemnets you mentioned in your posts. Now all we need is the TSBs or what not, a few burned out bulbs (28 VDC should do the trick ), and I'm off to the good times.

Couldn't resist. (j/k)

 

Sorry I don't do TSBs.... Mercedes doesn't want them copied or reproduced, distributed or whatnot, and I respect that.

 

In that case it would be best not to make hints. I know that puts you in a bind as you have shown willingness to help numerous people with your knowledge. But its a choice you will have to make and live with. I don't think that every stealer service department, based on posts on this forum, is as capable. Some of the posts on here have shown that the opposite appears to be true with the repeat visits of members for issues. No flame, just $0.02.

 

I will tell you there IS a bulletin, I will tell you there IS an updated part... But as for posting a verbatim copy, I just won't. Sometimes you just have to tell the dealer that you do know about an update to make them search harder for it, I have been there myself for other car makes. Not everyone who works at a dealership is passionate about cars. I personally don't understand those people. I love what I do, and wish to help others who enjoy the same things as myself. I won't take a chance, even a small one, on jeopardizing my position. I just cannot see myself doing anything else should the worst happen.
Try to keep in mind there is a definate shortage of good techs... The dealers need bodies in the shop, so they take what they can get. This compounds problems for a vehicle as complicated as a mercedes, because it takes an even more highly skilled individual to work on these cars. Also bear in mind many times there is simply no fix available, or no adjustment to be made. The car is the way it is until Ma Benz decides to do something about it. We are at her mercy also. A large number of problems we deal with are software related. We don't have the resources to fix these problems ourselves. We must rely on updated software, which gets released when they get around to it. It is also not as easy to just drop your car at another dealership, given that mercedes dealers are often far apart, so your car ends up going to the same place, and often to exactly the same technician who worked on it before. Many shops have a comeback policy that requires the previous tech to look at the car if it comes in for any reason during the next 90 days. I do NOT agree with such policies, but there is nothing I can do about it. The tech may simply get sick of working on the car and blow it out the door as quickly as possible.
Techs also suffer from the same things encountered my many other people in the service industry. Customers who refuse to read owners manuals and don't understand why the car doesn't work as they expect it to, is one of my primary gripes. Its not fair to waste a minimum of a half hour of my time to look at a problem that simply does not exist. We rarely get paid on such claims, and we have to make a living too. I try to maintain a 200% efficiency level, so that half hour I wasted ends up costing me 1 hour of paid time. No repairs made, no pay. Some techs try to circumvent this by "throwing parts at it". That doesn't work. If you admit there is a problem by attempting a repair, then the customer expects a solution, even if that is actually how the car is supposed to operate!
Then there is the service advisor, whom we rely on to translate the customers complaint. More often than not, they get it wrong. The description of the percieved problem is way off, indecipherable, incoherent, poorly spelled, and grammatically incorrect. "Client states seat does not work." What the hell does that mean? Which seat? What exactly doesn't work? Lessee, lumbar, power adjusments, seatbelts, storage compartment, what? Is it making noise? Heated seats? Ventilated seats? Then you go and function test the seat and find it works just fine. The advisor was too busy to get ahold of, or if you could find him, then he calls for a better description of the problem but the customer was unavailable.... Wasted at least a half hour... NO PAY. See where I going with this? Sometimes it boils down to a lack of motivation because of scenarios like this. Why should the tech put forth any more effort? He didn't get paid for it last time. Nobody noticed he was trying hard.. they just saw he didn't fix the car properly.
Damn I just realized I am ranting... Sorry. Enjoy the view from the other side of the fence!

 

Thanx for the very informative post and the explanation of the inner circle/workings. I do agree and support your stance. Maybe I didn't express myself properly on TSBs.
In the past I have been able to approach my stealership with an issue and a TSB # in hand, not an actual copy mind you. Maybe I'm lucky in this case because my SA appreciated the fact that I did some research and found a possible solution. The techs also seem to be in agreement. I guess that goes with your saying above in regards to spending time wisely. I was able to do this because of the info found on this board. Therefore I believe it helped both parties: informed consumer, and a tech who can do his job faster with more quality by not spending his time on a lot of research.

P.S.
Bringing donuts for them at times has helped on special requests: i.e. no charge software setup changes that other dealers charge for.

 

I appreciate the hints saturnstyl. In some cases I can check or do the fixes myself and avoid the aggravation, time loss, and damage to my car associated with taking it to the dealer for warranty repair. Although I sympathize with the independent repair shop's situation a dealer's mechanic 'should' be in the position to make a living AND provide a reason to continue doing business with the dealer. You can change mechanics but when the manufacturer lets you down then the option is to buy another brand. Unfortunately the current auto repair situation encourages dealer mechanics to emphasize 'do it fast' over 'do it right'. There should be a better balance between the two needs. As long as repair continues to be a profit source the problem will only get worse. Once again, thanks for the hints, and keep them coming.

 

An independent has an easy life in my book. If they don't want to work on it, they can turn it away. We have to work on it no matter what, we are the dealer. An independent can charge what they feel the job is worth, at a dealer you get paid what warranty wants to pay you.
And when the independent gives up, who do they tow the car to? You guessed it. There are ups and downs to both sides of it.

 

Mine had been fine for almost 3 years until 2 days ago, when the front right turn signal went. When I got the bulb with the socket out of the light unit, it turned out that the bulb and the socket are both fine, but one of the contacts connecting the socket itself to the unit is charred and has a hole burnt through. Sanding it didn't help, as the respective contact on the unit must be charred as well and I can not reach in to clean it. My service advisor asked if updated harnesses had been installed, to which I answered "no". So the car is going in the shop in a few days. I also asked him if there is a TSB for that - his answer was "yes".

 

My parts came in today but I am not sure I got the correct stuff. I have the lamp supprt, hard plastic thing that the bulbs go in and all new bulbs. I will replace them and see what happens. I told them I wanted to buy the "taillamp wiring harness update" and this is what I got.

Then, my freekn' front passenger dim light bulb blows and passenger fog light at the same time.

More tonight...my wife is pulling in with the car.

Eric

 

Be sure to check out the post right above this one.

The lamp support was the wrong one and does not fit properly. :-( So I took all the NEW bulbs and put them in the old lamp support and nothing. Same error. All bulbs work, but I get the fault.

I took a look at the taillamp wiring harness and it looked like it ran along the rear of the car behind the plastic thing near the hatch lock toward the driver's side of the car. Is it a long harness? Does it go over to the driver side and hook up there?

Thanks! I will return to the dealer and try and get correct parts. Thanks fore all the help so far SaturnStyl. We are getting there!!

Eric

 

No, bulb supports are not what is needed. There are taillamp harnesses, that plug in between the existing harness and the bulb supports. They are 8-10" long, its a 2 second installation. This reduces the amount of voltage at the bulb to make it last longer. A similar fix exists for the license plate bulbs too. The front turnsignal updates do not use the resistor wire.
203's seem to have a lot of bulb troubles.

 

I got the bulbs working.

This is a little embarrassing but I will fess up the truth.

The small bulb on the bottom corner was out. I played with the bulb some and finally got the new bulb to come on. Evidently, those bulbs are picky about how they get seated. There is a little bit of corrosion on the contacts but not too bad. I may put the new lamp assembly on anyway, when the correct one comes in.

-----

I went back to the dealer today and met a new parts guy I hadn't dealt with before. It turns out we go to church together and he knows my sis-in-law. So, I turned up the heat on the wireing harness. He asked the head parts guy and he claimed there was no harness for the tail lights and that it is only for the front parking light. Not being satisfied, and him seeing this, he went back adn checked with one of hte Tech's for me. They also claimed that there was no harness to install.

Go figure. I know this crap will come up agian because this is the second time this has happend. The first was under warranty and I never did find out what they did. Who knows, it may have been another case of it ain't seated properly, but I thought I remeber it being more involved than that.

Thanks for the help! Much appreciated. It is about time for another website update or two. If I can get my new web editing software learned.

Eric

 

I meant to get the part numbers for you today... I got busy. Hopefully I will remember tomorrow.

 

Thanks. Insert big evil grin here.

Eric