Strange Stop Light Dash Warning Behavior
 

I have the 2001 X5 3.0 Sport... Three weeks ago I the dash board chimed and the indication was that the Left rear stop (brake) light was out. I checked. Sure enough it was.

I took the bulb out of the carrier and tested the bulb on the bench. Looked fine and the filament was not broken although the bulb has a slight dark spot on one side. Put bulb back in but still not working.

Went to NAPA and bought a two-pack of the bulbs. Replaced it. It worked. Dash warning is out. All was fine. Week later the Right side goes out while I was on a trip. Ha! I have the spare. Put it in and all is well again.

Day later the Left rear goes out again. (?) I was still on the road trip so I ignored it... several hundred miles down the road the dash warning goes away and the brake light works normally.

Next day it failed again- light on dash came back. This situation "fixed itself" again but it went out several hours later.

Bulb still looks new, and tests ok on the bench.

Ideas?

Ah yes the dreaded tail light out problem...

I'll tell you what the solution is. The bulbs are fine, its the actual gizmo that holds the bulb. The metal filaments or parts on the plastic housing that holds the bulb are corroded or are not getting sufficient contact to the other metal connection pieces on the actual tail light housing unit. Take the gizmo that holds the bulb (remove the bulb obviously first) take some sand paper and scrape those metal pieces on the gizmo that holds the bulb. Do it for a while and blow the dust or shavings off. Put the bulb back in and put that back on the tail light assembly. It should work. It should stay working. That bulb out warning shouldn't come back.

I'll give it a try. The carrier gizmo was suspicious to me already but thanks for the push. Did you have a similar problem?

It's extremely common.

I had this problem and after countless hours of research and trial and error I finally narrowed the problem down. It worked. It won't be as easy as 1-2-3. I had to keep sanding, and keep trying and finally it worked and stayed working. But this method DOES work.

You'll have to put something on your brake pedal to press it down and then look at the lights yourself to see if they are on. If one of them is flickering a little bit, then you need to keep sanding the metal filaments and try again. The whole process took me about an hour. But there are no more bulb out warnings and all tail lights work and fire up nicely without any flickering or problems.

There's something about driving a BMW and having a tail light out that just doesn't sit well with me. This problem drove me crazy until I finally figured it out...

Coat the contact points with high temperature CONDUCTIVE grease. Just a little blob to help maintain electrical contact will do. It will solve the problem.

I had this problem early on in the X's life, back when it was under factory warranty. they replaced that 'gizmo' that holds the bulb. I think its a socket or something?

Yep, the 'ol bulb holder socket... In some cases it actually burns a little spot on the tail light, where it contacts. Sanding the contacts clean and adding small dabs of conductive grease on the contact points of the bulb/socket and cosket/tail light will be the long term fix.

I'm asking this for a friend. He just had a local mechanic replace a
tail light bulb on his 2001 3.0 and now the warning light on the dash
board is on. His mechanic said that he has to have the car
reprogrammed in order for that warning light to go out.

I don't believe that is correct. So I'm asking the experts. How say you?

You don't have to reprogram the car to turn the light off.

Of course, if this mechanic charges to replace bulbs, I'm surprised he doesn't offer this "reprogramming" service for the low, low price of $250.

...sounds like the kind of guy who'd charge you to refill your headlight fluid...

Not sure what kind of repairman this mechanic is.
I'm Just trying to compile some written information
in order to help my friend understand that what I'm
telling him is the truth that reprograming
is "NOT" required

Remember that half of the taillight bulb issues are burnt contacts between the bulb socket and taillight housing circuit.... they might simply be overlooking a common/known issue. And there isn't any programmable fixes for the E53 taillights as you already know. (not like an aftermarket shop is likely to have BMW programming software anyways) Your friend should show the shop the real issue, that should have been apparent when changing the bulb... then call them out to show the information showing a programming fix. (bulletin etc.) Well informed customers can't be taken advantage of by shady mechanics.

Thanks weasel,

What I need then is the bulletin that spells it out. He's the kind of guy that he's been using his mechanic for years and trust what he says so anything written that will support the facts we already know will be helpful.

Thanks