Bulb warning lights errors and light wont turn off

[Deano1963]

Hi New to this forum. Recently bought 2003 S320 (W220 I think).
It recently started showing bulb warning for tail (Left & Right) advising substitute lamps being used. I've replaced both bulbs and these now work but the warning persist.
In addition the rear substitute lights now stay on even when the car if locked and is draining the battery. Have tried all the different setting on the lighting dial with no luck. Anyone else come across this?

 

[Blobcat]

Hello and welcome

Did you use normal lamps or LED’s ? Most LED’s activate the lamp failure warning as they don’t give the same resistance

Early 2000 Mercedes can suffer with corrosion on the lamp terminals, the lamps still illuminate but the warning will trigger.

 

[rifiki]

Agree with Blobcat, also clean the contacts on the bulb and lamps

 

[mersum1es]

Light switch failures are common in W203

LOL sorry I misread car info---

 

[mattkh]

Hi New to this forum. Recently bought 2003 S320 (W220 I think).

If you look at the chassis number, after the first 3 characters will be six numbers.
The first 3 numbers of that will be the W number for your car.

 

[Deano1963]

Thanks MattKH. Any thoughts on the faults or is the diagnosis dependent on the W number?

 

[LostKiwi]

You may need to tell it via diagnostic that the fault has been cleared.

 

[Botus]

which bulbs is it saying to check

as eluded to above Merc and BMW use the expected resistance / current pulled on the light circuits to flag up if a given bulb filament has popped. Its all rather simple to do on the way modern cars are wired up using canbus control.

not many others go to the extremes theses brands do - my focus doesn't care if a bulb is playing up with the exception of a direct short on the brake lights that took all three out and in diagnostics mentioned it - never informed the driver !!! Crazy, all it was was the filament on one fell off one end, and somehow took the lot out (nice fail safe!!!)

Many nasty LED illegal fakes claim to be Canbus error free - but they really mean should work on most cars, but could well play up on a BM or Merc (9 out of 10 ads say this).

On a BM bike I swapped two dim yellow w5w (T10) site lights for a set of "error free LED bulbs" to better match the xenon headlight. They were error free when the felt like it... They always lit up but 50/50 if the bikes bulb warning message felt like coming to the party or not

 

[Deano1963]

Thanks all. It's the tail lights. Replaced with standard (non-led) bulbs from Halfords. Not sure how to reset via diagnostics but next step will be to clean the contact. Would fine glass paper do the trick?

 

[LostKiwi]

Thanks all. It's the tail lights. Replaced with standard (non-led) bulbs from Halfords. Not sure how to reset via diagnostics but next step will be to clean the contact. Would fine glass paper do the trick?

Use wet and dry. Glass paper will shed bits inside the holder. Simply fold some over the end of a screwdriver and gently rub. Then carefully set the contact by bending towards the bulb a little.

 

[mioba]

followed by a shot of contact cleaner - with everthing switsched off then a blow dry prior to refitting

 

[LostKiwi]

followed by a shot of contact cleaner - with everthing switsched off then a blow dry prior to refitting

Use Switch cleaner rather than contact cleaner if possible. Switch cleaner is non conductive whereas some contact cleaners are.