DanSheffer

Hi all
I do you delete a message? I get this message every time
my headlights are on "tail lamp right auxiliary bulb on" I replaced
the bulb and still get the message. I tried holding down the rest button with no luck. I have reset the "service A/B" before with no problems.

GotDaBenz

Are you sure you replaced the bulb that was out?

DanSheffer

Thanks for the reply GotDaBenz(like the name!) yes when I took out the bulb it was black
on the one side. All the others looked fine. From what I've read the one I replaced is the right tail light. I could try to replace the other (brake light) since I do have another spare bulb to see if that might fix the problem but it looked fine when I checked.

samaritrey

I would get someone to sit in your car and use the brakes and all lights and look to see what bulb is in the wrong spot. If that does not work switch bulbs from side to side. and if the same side still does not work get some steel wool and have at the connector or some people have luck with an eraser. our cars sometimes report bulbs out even when they work when the get old and start drawing different amounts of power it flags the system. Another thing I did years ago now was replace all exterior bulbs and that helped a lot. I was having a bulb fail like every two weeks every time I went to one friends house. So one day i just went to the store and bought every bulb my car needed and replaced them including the fog lights. Then i saved the bulbs as spares.

MW_ATL

+1 on cleaning the contacts in the bulb carrier. Especially if you see it working fine for several days and then it decides to throw the errors on others (in my case it was whenever the humidity went up).

JLD2k3

The tail light is the lower outside light and it is smaller and shaped different from the rest of the bulbs. I only bring this up because you mentioned that you had another spare bulb and it sounded like you may have meant that it was the same as the one you replaced.

2nice

hi everybody. i am having the same issues. the error messages i was getting were:

tail lamp left
left auxiliary bulb
tail lamp right
right auxiliary bulb

i got this diagram from the owners manual. (i have a 2007 c280 4 matic. i dont know if it makes a difference between models.)

manual reads:

bulb 8: brake lamp
bulb 10: parking and side marker lamp
bulb 13: Rear fog lamp (driver’s side only), tail and standing lamp


i replaced bulb 8 and bulb 13 on each side. now the errors that i am getting are:

tail lamp left
left auxiliary bulb

i guess i should try to clean the connectors? i will update when i do.


i assume you are speaking of bulb 10.

this brings me to another thought...is bulb 8 the light that should be on when i turn my lights on? or is bulb 8 acting as the backup? when i turn my car lights on, bulb 8 on both sides are lit up, and when i press the breaks, both bulb 8s get brighter. are they functioning correctly? i feel like i've seen w203s with their lights on and just bulbs 10 and 13 were lit up... i couldnt find any pics when i searched though.

havoc_vulture

I had this problem before ... a guy at a lube shop (oil change not astroglide Haha) told me that you have to use Mercedes Benz specific bulbs... he had them on hand replaced it and the message went away ... seemed odd when he told me and I never bothered checking them to see the difference .. and currently I don't have my car to go check it for you but maybe you could look into that ?

DanSheffer

You will have to replace both left tail and right tail light bulbs then the messages will go away. Your Aux light message is the "backup system" tail lights
that come on when either tail light or both are burned out. After this happened to me almost every other bulb went out as well, I've pretty much replaced them all lol. It's a little tricky but just work the bulbs in, turn the lights on only the bottom ones should be lit.

2nice

when you say "tail light", you mean bulb 13 right? i already replaced those...

but thank you for the info that the bottom should be lit. are bulbs 10 AND 13 supposed to be lit or just bulb 13?

DanSheffer

If you're still getting the error message the bulb is not in correctly. I had this problem also. Make sure the bulb is dim when lit NOT bright, you have to turn it a certain way almost kind of barely in the socket sort of if I remember for it to lock in correctly. It took me awhile and after getting frustrated for 45 min I got it in correctly, finally! Then of course my left brake light went out days later! Ugh. I replaced both bulbs 8 and 10. Good luck!

DanSheffer

Sorry I meant bulbs 13 and 10!

2nice

ok i figured this out and i'm gonna try to explain for future users.

i replaced bulbs 8, 10, and 13 on the RIGHT side and the errors messages went away but the brake lamp (bulb 8) was still functioning as the tail light (aka it was lit when i turned my car lights on) AND it was functioning as it should as the brake light and got brighter when the brakes were pressed.

i thought after replacing bulbs 10 and 13, the right light would function normally (10 and 13 lighting up when lights are on, 8 brightening when i press the brakes) but this did not happen.

THEN, i replaced bulb 10 on the LEFT. (I had already previously replaced 8 and 13 but was still getting error messages for tail light and auxiliary light)........and the rest of the errors went away for the left side
AND
lights 10 and 13 started to act normal (lit when lights on) on both sides. bulb 8 was now only acting as the brake light, staying off while the lights were on, but brightening when i pressed the breaks.

moral of the story: even though the bulbs were all fine and the error messages were gone from the right side, the benz kept the right side functioning the same way as the disfunctional left side until everything was fixed. the benz wanted symmetry? haha.

MW_ATL

I just had the same set of messages occur on my Coupe, with the same symptoms! Glad you posted this, as I thought I had replaced the bulbs recently and assumed I was having another problem. I should have just given it the spring sacrifice of a full set of rear bulbs this year, like normal. I've found a set a year keeps it happy.

I will be picking up a set tomorrow. I have found through experience that MB bulbs work much better in the cars than other brands -- well enough and longer enough to be worth the extra (especially since my SA will usually hand them to me).

I am adding pictures of the errors and the behavior, just to help with the thread.

FrankW

replace the bulbs and also check the fuses. also make sure you get the correct bulb.

mleskovar

Early in my car's life I had a lot of problems with the rear lights. MB even replaced the light carrier assemblies. I made an interesting discovery (for me anyway). Even though the light illuminates it doesn't mean the bulb is OK (like you noticed).The bulb can still illuminate but the resistance of the filament could be wrong causing the error to be tripped. The filaments are only a couple of ohms so even a slight change would be picked up as an error. That's why Frank's suggestion of getting the correct bulb is important. There's more than just fitting the socket.

2nice

@MW ATL...thanks for the addition of pics but i'm confused. i dont see what's wrong with the left side...clarify?

@mleskovar....
Yes i agree, the bulb TYPE must match...sometimes this can be tricky because the bulb package doesnt always give this info...you gotta actually read the small print on the bulb itself. and it doesnt help that sometimes the advanced auto parts or walmart employee has no knowledge of this haha

I took this out of the manual:::

Lamp -------------------------------Type

7 High mounted brake lamp ----------LED
8 Brake lamp -----------------------P 21 W
9 Turn signal lamp ----------------PY 21 W
10 Parking and side marker lamp -------P 21/5 W
11 Backup lamp ------------------------P 21 W
12 License plate lamps ----------------C 5 W
13 Rear fog lamp (driver’s side only), tail and standing lamp -------- P 21/4 W

Russell Ormerod

Good tip frank, always use correct wattage bulb, also a W203 does not have fuses for the exterior lighting, all monitoring is done by SAM modules

MW_ATL

I will hopefully finally get the bulbs in mine this week end and take a picture of "normal" operation.

But to explain -- normal is that the top section of the tail-light never lights up unless the brake lights are on. They are not normally illuminated as a running light. It isn't supposed to get brighter when you hit the brakes -- when you press the brakes you have 3 lights that all come on: The top of the left tail light, the top of the right tail light and the CHMSL in the middle. The back of these cars actually makes it VERY obvious to people behind you that the brakes were applied. I like it a lot.

MW_ATL

Ok, the new bulb holders did not help my issue at all. The issue, it appears at this point was in the adapter harness that was a retrofit on pre- December '02 cars. This was an adapter that reduced voltage to the tail-light bulbs by about 1 volt.

When I put the new bulb carriers in, I got the same messages, plus a new one about the rear fog light. When I went back to the original bulbs and holders, I continued to get the same messages, but when I removed the adapters, everything cleared, making me believe that the left side adapter is bad (it was also warmer than the right side).

These appear to simply generate resistance to drop the voltage. I have attached the DTB for this issue as a pdf and I will try to post pictures of the adapter harness itself tonight.

Again, it appears to be only cars built before about December 2002, the DTB says that after that date the cars use a different wiring harness that has the resistance built in (that could be good or bad, I guess).

samaritrey

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT
Good price I got mine for $19.90 + shipping good price for two

MW_ATL

Good price, I think list is about $30.00 or a bit more each.

Right now I am running the car without them, I'm just puzzled why the new bulb carriers were generating the same error even with the bulbs from the old carriers in them (and the adapters removed). The automotive gods are playing games!

krazzdav

Thank you everyone for your posts in this thread. I had the same problem as I just quoted above where it was saying my reverse light was on and my brake light acted as the tail light but got brighter when I stepped on the brake. I thought my SAM started acting up or bad contacts but low and behold it was a burned out tail lamp bulb...the small 5 watt one and was on the side that the error said was in fault. Though the error in the dash was not what was really wrong it's pretty slick of MB using the brake light as the tail light when one of the bulbs failed so you still have both sides. Lol