W212 Facelift rear LED fault

[HB]

I see quite a few facelift 212s with dodgy rear lights. The ones attached to the boot are normally working but the ones on the body seem to fail . Must be a common fault.

 

[Zix]

I tried today this method on my both tail lights. Now they're working perfectly.

 

[applecross]

Brilliantly helpful - what a great first post!

Welcome to the forum

Agreed. Great post. Followed this method and it worked.
My only advice would be to use a hot utility knife as it cuts a nice neat hole with no mess. Just replace the plastic cutouts and use the hot knife to reseal around the edges. Does a very neat job.
Thanks aheinonen for a very useful post and a simple fix.

 

[dowite2003]

There is no need to take the rear lamps a part. Here is a way how to fix them. This lamp is from LHD car and this lamp is from left side "view from behind". Those should be pretty similar in RHD and LHD cars as far as i know.
You can cut these "service holes" where you get access to these three connectors witch usually are the origin for the problem. Just solder with tin those three components and you are good to go.
I used dremel to cut those service holes and vacuum cleaner was sucking the plastic chips whole time i was cutting, inside the lamp remained clean.
You can glue the plastic peaces back on it or just use some strong tape to cover the holes.
The whole job took about 45min and i saved 350€


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Hi thanks for a great post. I have the same problem on the right rear light. I have never attempted something like this but do a fair bit of DIY so would be able to do it. can i please ask once you make the holes in the plastic, do you see the broken connection between those white wires and the connectors or something else. sorry couldn't get that clear from the pictures. And is that those wires that you solder back onto those connectors? many thanks for your help and advice.

 

[Peteriri]

hi
I bought new complete W212 tail light after old one have a flickering issue (a common fault).
after instaled LEDs are working all good including right turn signal LEDs row.
the problem is that the message comes on the dash:
---The rear signal bulb needs replacement (also the sound for turning right is faster as when one of the bulbs need replacement )

• anyone know what's wrong as a lamp its brand new ordered from eBay Germany, if refit the old unit, dash message disappear ..

 

[silver1011]

Does the new tail light function correctly i.e. do all the LED's illuminate?

 

[silver1011]

Hi thanks for a great post. I have the same problem on the right rear light. I have never attempted something like this but do a fair bit of DIY so would be able to do it. can i please ask once you make the holes in the plastic, do you see the broken connection between those white wires and the connectors or something else. sorry couldn't get that clear from the pictures. And is that those wires that you solder back onto those connectors? many thanks for your help and advice.

You don't touch the wires, all you're doing is renewing the solder on the three resistors inside the white circles in the pictures posted back on page 1.

A soldering iron and some fresh solder on each end by the look of it.

I'd never heard of a hot knife before, but they look as though they'll do a cleaner job of cutting the plastic than a Dremel. I might have to invest.

 

[Codger49]

hi
I bought new complete W212 tail light after old one have a flickering issue (a common fault).
after instaled LEDs are working all good including right turn signal LEDs row.
the problem is that the message comes on the dash:
---The rear signal bulb needs replacement (also the sound for turning right is faster as when one of the bulbs need replacement )

• anyone know what's wrong as a lamp its brand new ordered from eBay Germany, if refit the old unit, dash message disappear ..

Was the light unit you bought intended for a rhd car?

 

[silver1011]

I initially thought the same, but the fault is with the outer cluster, the single sided rear fog light is incorporated into the inner cluster.

 

[Peteriri]

Yes everything works correct ,how soon I touch right signal command message comes on dash.

"On the main time I soldered the old unit and fitted back ..new lamp still on the box "

Does the new tail light function correctly i.e. do all the LED's illuminate?

 

[silver1011]

Strange, perhaps the car is able to tell that the light cluster is not for a RHD UK-spec car?

I know with some manufacturers that if bulbs or LED's fail, the car is able to utilise other working LED's to perform the same role. Perhaps there are some hidden differences between RHD and LHD light clusters?

When the original tail light failed (before you fixed it), did the car not alert you to the fact it was intermittently failing? Seems a little disappointing on a modern car that something as significant as a failed tail light wouldn't be brought to the drivers attention. My 2002 BMW 3-Series even managed this, more than 15 years ago!

 

[richard]

Hi. Car can’t tell difference - ie no clever ID electronics in the lights. Bulb failure detection can’t work well on LED taillights because they take so little current - with standard bulbs it’s easy to measure.

 

[Abb]

When the original tail light failed (before you fixed it), did the car not alert you to the fact it was intermittently failing? Seems a little disappointing on a modern car that something as significant as a failed tail light wouldn't be brought to the drivers attention. My 2002 BMW 3-Series even managed this, more than 15 years ago!

My inner tailgate LED cluster failed in the same way and I can confirm you don't get any notification on the cluster, as COL pointed out there is not enough current difference for the car to recognise it.

 

[silver1011]

Which all makes sense to me, it was the earlier comment that made me ask the question as to the bulb monitoring system...

"...the problem is that the message comes on the dash: The rear signal bulb needs replacement."

Which would suggest some monitoring of the LED's is happening. It was confirmed the LED indicators were working, but accompanied by the fast flash tell-tale and on-dash warning above.

 

[Gary2019]

I followed the instructions from the DIY post today, carefully used a hot Stanley knife to cut out the little service windows, using magnifying glass touched both sides of the resistors with soldering iron x3 resistors. My rear light was off all 100% of the time and it worked my light is now fixed. Great post saved me a packet. I also sealed the window back up with a hot knife too. Jobs a good one.

 

[silver1011]

Do you have a link for the Stanley hot knife, I might have to invest!

I assume you're not re-soldering the joints, you're simply briefly melting them?

 

[Gary2019]

Do you have a link for the Stanley hot knife, I might have to invest!

I assume you're not re-soldering the joints, you're simply briefly melting them?

 

[Gary2019]

Hi

this may sound cheap, I just used a normal stanly cut knife from a hardware store £4 and heated it on gas stove/home cooker. It worked perfect cut clean windows out, just be carful not to push it to far through to avoid coming into contact with the two wires that hang loose. Trust me it’s better and easy to do. My lights are working perfect now.

As for solder I did ad a very small amount of fresh solder I not sure if it was needed but I used a tiny tiny bit.

Gary I have photo but file says to large to add.

 

[silver1011]

Brilliant, thanks for the tips!

 

[F1ant]

Completed the solder fix as described by aheinonen. Light now working again, very happy!