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Exterior Bulb Warning light on but no deab bulbs?

120K views 28 replies 13 participants last post by  Butlerg 
#1 ·
Hi: For a second time I get an exterior bulb warning light but it seems that all the bulbs work, although I can't verify if it's the panic brake light bulbs, or for that matter, something in the trailer harness wiring (I have the factory version).

First time it came on, after a few miles and a few trips, the front lights flashed on and off all by themselves (can't be sure if it was the fogs or the mains) and the warning light went out. Some sort of auto-reset?

Now a few weeks later and the warning light is on again. I'm beginning to wonder if it's the control unit (is that called the LCU?)

There is another thread where the OBD2 code indicated a thermostat heater problem, but the thread did not come to a conclusion.

http://www.bimmerfest.com/forums/showthread.php?t=513214&highlight=bulb

Any thoughts out there about what I might look for?

Thanks in advance
 
#2 ·
I had the warning in my '06 and couldn't find a dead bulb anywhere. Then I tried it again at dusk when I could actually see the lights and not a reflection of the sun and lo and behold I found the dead bulb. Changed it out for a $3.00 Sylvania and was good to go. I would check again in the low light level. I could have sworn that bulb was good when I looked at it in the light, it seemed to be "on".:confused:
 
#3 ·
Yes, you really have to look carefully.

It's not just a case of sun reflection - the built-in redunancy means that when 1 bulb is dead, one of the others (such as the high-intensity brake bulb) is commandered as a substitute.
So you will normally see lights on - just not the ones that normally should be.

The thermostat heater code in that other thread is a red herring - old codes are stil retrievable by the dealer's GT1 computer even when the SES light has been turned off by a standard code reader.
Sort of like your computer files are not really deleted - just marked as so in the access table.

However, in the present case, it does sound as though there is some odd problem with the light control function.
Could be just moisture, or a bad connection somewhere.
Don't think there is any sort of auto-reset for the bulb warning light - it normally stays on until the bulb in question is replaced.
Might be worth getting a few new bulbs and try replacing them all.
 
#4 ·
Off again On again

The warning lite went out on a brake pedal tap then back on a couple of stops later. Am beginning to suspect brake lite bulbs or contacts. I'll replace them first.
 
#6 ·
Found it

It was a dead bulb. Got a matching bulb from the local parts store and it works and the idiot light went out right away. I can't explain the earlier behavior - that's one for the Journal of Irreproducable Results.
 
#7 ·
Mine only manifested when the brakes were panic-depressed. Apparently that bulb was out but otherwise the usual walk-around-at-night inspection/flasher check was fine. I would have never known. Dealer replaced as goodwill and it was under warranty anyway.
 
#8 ·
Be careful with autoparts replacments`

You need to get the ones with silver bases, not the brass ones. Otherwise they will not work for long if at all and the dash light can still trigger. Something to do with the resistance I think of one material vs the other plus the brass corrodes a bit easier.
 
#9 ·
You need to get the ones with silver bases, not the brass ones. Otherwise they will not work for long if at all and the dash light can still trigger. Something to do with the resistance I think of one material vs the other plus the brass corrodes a bit easier.
Thanks. It is silver color not brass so I guess it is the right material. We'll see how long it lasts.
 
#12 · (Edited)
No visible bulb blown - but warning in the dash (E83 2007)

EDIT - replacing the blown rear right lower brake Light did NOT solve it...:
It was as simple as one of the normal rear brake lights. When I previously inspected myself against a large supermarket window I did not notice that the car is so smart that it uses one of the rear fog (and also panic brake) lights if the brake light bulb is blown. So much for tearing down the tail lid and checking all bulbs at the back. I did check the brake light bulb but failed to see that is had gone. When I checked again by backing up to a large window I saw that the brake light was assymretrical. Case closed and one hour wasted :)

Now I have the same problem. I saw this a long while ago when the bulb holder for one of my two rear fog lights had been a bit burnt where the bulb socket meets the holder. Scratched that away and was all good. Now 1½ years later I *think* I have checked all bulbs but still have a warning.

The following bulbs are working:
2x high beam lights
2x low beam lights
2x front fog lights
6x turn signals around the car
2x white reverse lights
2x rear fog lights (in EU they are next to the reverse lights on the lid)
2x registration plate lights

Questions:
  1. How can I test the panic brake Light - just sit still and brake all I can?
  2. Are the panic lights an extra set of own bulbs only used for panic brake illumination?
  3. Does the warning Light only react to exterior lights? I have not gone through the interior but think all are working.

Really appreciate some input. Very close to buying a China OBDII reader now... Hate to take it to a shop for a light bulb.
 
#13 · (Edited)
Hmm, I bought a couple of new W16W 16W light bulbs from my BMW dealer. I replaced the blown one first - no succes. Then the second brake light one as well and still the warning light comes on. Any ideas greatly appreciated.

I have gone over the two rear turn signal bulbs, brake light bulbs and the fog/panic light bulbs and checked for corrosion. All looks good, even the fog light which seat was burnt 1½ years ago.

One thing I am thinking about is if it possible to force the panic light on? I am unable to get the red lights which are used as fog lights here in Sweden to light up by pressing really hard on the brake.

Question: Can you get your panic brake lights light up by pressing the brakes hard at stand still?

At the moment I can only turn them on by pressing the rear fog light switch.

Another EDIT:
Now I found the culprit. I totally overlooked the parking lights. When I turned them on there is no light on my front right. It uses the same bulb as the turn signal - which is working... Should I be looking at fuses now or just replace the bulb?
 
#14 ·
.... Should I be looking at fuses now or just replace the bulb?
Just replace the bulb.

Fuses blow when there is a fault that needs to be addressed before putting a new one in- it's not that fuses just wear out like light bulbs.
(But they can work loose in rare cases.)

Not that you need worry about it now, but the panic brake light cannot be tested when stationary.

It is activated by a deceleration rate and involves the ABS.
 
#18 ·
Alright, some idiot had taken out the 5A fuse for the right parking light and never put it back in - causing some headache :) The left parking light had blown so I'll swap that and hope all works then.

When I turn on the parking lights now the left blown bulb is replaced/overtaken by the left turn signal and the right parking light shines.
 
#20 ·
That's correct. North America mandates an "amber" light at the front corners as our parking lights, so BMW just omits the standard parking light that is normally housed inside the high beam and uses the turn signal instead.
 
#21 ·
Thank you all for the notes on this. I am having the same issue. My "dead bulb" warning light came on. BUT, jsut before it came on my car was idleing a little rough. It has done this before, and does it periodically. I had the spark plugs changed recently... So I am coming in to town from a long trip, I stop at a stop light, my car bogs down a bit at idle and the Dead Bulb light comes on. Checking all around the car I do not see a dead bulb. Am I going to have to go in and check each one for dead bulbs and corrosion?
 
#22 ·
BigShark, maybe your car is a US-make but for me the real culprit has been the rear fog lights (2 in total, one on each side of the plate) which you can light up manually with a button by the steering wheel.

My first warning light 1½ years ago was that the bulb "seat" for the rear fog light was a bit burnt but the bulb still working. I used a screwdriver to get it back to bare metal. It has been working fine until now. After inspecting all lights this time I actually got the light on again, luckily before having put the liner back up. It proved to be the buld holder being a tad bit loose in it's seating so it would wiggle a bit. I was able to bend some tiny metal flaps so now it sits very tight.

Hopefully I never have to tear down the lining again. PIA to get it back when you are alone :)

PS. I have a 2007 year model and except for the one burnt rear fog bulb seat every other looked like brand new.
 
#23 ·
Thanks Nikasp,

How do I check to see if this is the light that is out. Do I but on the Fog Lights switch and see if the bulb is burned out, or do I have to tear into the large plastic cover that covers the rear lid, or is it in the side lamps on the tails of the car which would be accessible from the interior? do you have any photos or can you point this out to me in the users manual where it talks about changing lamps? Thanks in advance for the help.
 
#24 · (Edited)
You have tail lights and turn signals easy accessible on the side. On my European model I then have two fog lights and panic brake lights inside the lid panel.

The lid panel is fastened with 9 plastic clips, two screws inside the grips/handles and also two plastic rivets by the locking mechanism on the the lid. I typically broke a few plastic clips and lost the pins on the plastic rivets, i.e. bought the rivets and a few clips.

Here is the trunk lid. I had to get 2 number 9 rivets (color matched) and a few number five rivets. Ah, and you have to disconnect the red/white trunk light and the plastic peice attached with the rivets before you tear down the lid.

Not sure what happened to my link but it was broken or not permitted, sorry about that. Check out bmwfans för trunk lid anyway.

Also: If you are inspecting yourself. Pay attention to that a blown bulb may be taken over by an adjacent light so you are very sure that you are looking at the correct lights.
 
#25 ·
I had to have one of my whole rear tail light assemblies replaced under warranty for a short of some sort. Warranty issue luckily.
 
#26 · (Edited)
finally fixed mine

I have an 07 x3 USA model. After changing my rear left brake light. The light was still on. Turned out to be the brake light bulb in the hatch. I think it's an h21w. All the bulbs lit up but the socket was kinda burnt. The socket doesn't seem to handle the heat of a halogen bulb. the halogen bulb is never used unless your brake light in the tail goes out or some say it lights up during a hard brake or some emergency braking.

It looks like ssoh was solved in the same manner.
 
#27 ·
Hi, I don't think it's the heat but the problem bulb did not fit 'snugly' in the socket on my car, allowing it to rattle a bit. I bent the metal parts in the socket ever so slightly so the bulb sits firmly in place now and should hopefully not cause more problems.

I have an 07 x3 USA model. After changing my rear left brake light. The light was still on. Turned out to be the brake light bulb in the hatch. I think it's an h21w. All the bulbs lit up but the socket was kinda burnt. The socket doesn't seem to handle the heat of a halogen bulb. the halogen bulb is never used unless your brake light in the tail goes out or some say it lights up during a hard brake or some emergency braking.

It looks like ssoh was solved in the same manner.
 
#28 ·
Burnt light warning...but only for a second!

Hi folks! I have an interesting light bulb warning issue here that I'm hoping someone has dealt with before. Any feedback would be sincerely appreciated.

When I start my 2007 335i Cabrio after a period of inactivity, e.g., in the morning after the car has been sitting still overnight, I get a light bulb out warning light. I've narrowed the issue down to one of the right-side turn signal lights because of the momentary quicker-than-usual flash intervals when I activate the right-side turn signal.

Here's the issue: The problem almost immediately cures itself before I can jump out of the car to see which light is not flashing. The warning light also disappears until the next long period of inactivity, i.e., the next morning, and the all of the lights flash at the appropriate speed.

I realize I can just replace every right-side turn signal light, but how the heck is this problem starting and fixing itself almost every day?

Thanks in advance for any feedback here.

P.S.: My old 2002 330i would at least tell me which end of the car and which side to look at to find the burnt out light bulb! Why did BMW go to a generic "burnt light" warning with no useful location information like the previous generation 3 Series offered?!
 
#29 ·
Blown brake light

I have just replaced a brake light bulb which has cleared the dashboard alarm message. Confusingly the bulb still worked, on inspection it looks like the filament had broken and then fused together again. Another thing which seemed strange is that the brake light would not work if the fog lights were on.
 
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