*edit - What triggers "LAMP DEFECTIVE" message?
 

I'm trying to pinpoint which bulb is setting off the LAMP DEFECTIVE message in my 97 E420. The message comes on at light knob position 1. This means city/parking lights, front sidemarkers, and rear tail lights? That makes it easy b/c i can examine only 3 sets of bulbs.

But I wanted to be sure that the warning message does not come on for those lights that are not activated yet; eg. if the 3rd brake light was defective, would that still trigger the msg to go off at position 1 and brake pedal not engaged?

What bulb does the manual call out?

2825 5W bulbs

on the W210 chassis there is a bulletin on installing a headlight repair kit to reduce the voltages...P-SI-MBNA-82/109, August 1998

The kit comes with needed parts & all new bulbs (except xenon).

The voltage should be standard for 12v DC. It is not high.
You should check the bulb sockets which might loose and caused arcing with the bulbs. When it happened the voltage can be very high due to electric arcing and will blow your fuse soon. Repair or replace loose sockets.

thanks guys.. maybe it's not the bulbs.

curious though, why do i NOT get the error msg when I turn the lights on while the key is not inserted?? what is different when the key is in vs. key out?

"why do i NOT get the error msg when I turn the lights on while the key is not inserted?? what is different when the key is in vs. key out?"

When you turn the lights on, it is just feeding the power to the lights. When the key is insert, it is feeding to the ECM as well to show message.

you might have a point here. on the driver's side sidemarker socket, the light won't come on if i insert the bulb all the way in. rather, i'd have to slightly pull it out and play with it a bit for the light to come on. interestingly the passenger side light also won't come on if the driver's side is off.

this is suggesting that the socket might be going downhill. does anyone know the oem part # for the sidemarker sockets, and price? thx!

edit- what triggers the LAMP DEFECTIVE message?
 

I'm trying to pinpoint which bulb is setting off the LAMP DEFECTIVE message in my 97 E420. The message comes on at light knob position 1. This means city/parking lights, front sidemarkers, and rear tail lights? That makes it easy b/c i can examine only 3 sets of bulbs.

But I wanted to be sure that the warning message does not come on for those lights that are not activated yet; eg. if the 3rd brake light was defective, would that still trigger the msg to go off at position 1 and brake pedal not engaged?

The 3rd brake lamp on 96-98 w210's never seems to activate the bulb check
message. I replaced 2 today that were burned out, yet there was no message in the cluster.
I think the factory forgot to tell the lamp monitor to watch the HMSL.
If you have bunk connections with high resistance, that will trigger a warning
message as well. Even if the lights are on and working ok.

DR.D

thanks. i still think it's my driver's side sidemarker socket, b/c i can see lots of green gunk & corrosion on the metal surfaces that contacts the bulb. I tried to squeeze a mini sandpaper in there to clean it out but i can't get rid of all of it.

is there a better way to clean the socket?

I have used small "needle" files before. And also put some silicone/dielectric grease in there when you are done to help prevent corrosion. However, I think you need to consider what M.B.DOC said since normally he is correct. Although I am not sure if the headlight issue he mentions relates to your issue.

Mike

fyi MB makes a kit with the pins to replace the sidemarker pins when they get corroded. I've used them on many 220's it probabaly applies to your situation as well. 000-540-09-66