Phantom bulb indicator

M

MX7

Member
2005 Z4 3.0i

I’m getting an intermittent dash light indicating I have a bulb out. While driving the dash light will come on. Later it will go out by itself even though I haven’t touched the light switch or stopped driving. Even with the warning light on, I cannot find a bulb out anywhere. Walked the perimeter several times last night and couldn’t find anything. Also checked for codes with my. Realtor 310+. Nothing.

Except…

I’d previously (3 yrs ago?) removed the bulb in the small storage compartment between the seats (and maybe the glove box if that has a light?) to stop the battery from dying. Did that years ago and never got the dash light before.

Is it the console and/or glove box missing bulbs causing this? Why would the light be on sometimes and not others? When the dash light is on I (think) I was able to trigger it by rotating the selector switch, but this too is inconsistent.
 
Should think it's one bulb that is intermittently loosing either it's positive or negative due to vibration or terminal corrosion at the bulb holder. When the fault is there and dash light some code readers will display which bulb is at fault.
 
Interior lights don't count (they don't read nor write neither.) Dodgy connection on an outside light.

My money's on a front indicator bulb. There the only ones I can say I've seen people have particular trouble with.
 
smorris_12 said:
Interior lights don't count (they don't read nor write neither.) Dodgy connection on an outside light.

My money's on a front indicator bulb. There the only ones I can say I've seen people have particular trouble with.
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Tbf, I have exactly the same intermittent issue with a front sidelight bulb. Warning light comes on, I drive about half a mile, first decent bump and it all starts working again.
 
Rockhopper said:
BMW Scanner 1.4 will show you which bulb is turning the warning light on.
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And will let you disable the warning for that bulb, too.

I had an e46 that would throw the error for a sidelight, even though the bulb was fine and working even despite the error being active, so you might be safe to just disable that warning.
 
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Thanks to everyone who responded. I’m a bit confused…. Did spuddymac hijack my thread? Either way, it’s all good.

Even with the dash light all lights were on. I’d ignore it, but it’s my wife’s car and I’ll never hear the end of it. Without the 1.4 scanner, what’s my plan of attack? Begin swapping bulbs? A little bulb grease on the connections? A small file to clean up the bulb socket corrosion?

If this was your issue (and no BMW 1.4 scanner) what would you do?
 
Mine did the same, warning on but all bulbs okay. Software told me which bulb turned the warning on, changed it warning went away and hasn't come back.
 
Take each bulb out, check the holders for corrosion, maybe give the terminals a scrape with the back of a screwdriver blade. If possible try and tighten them up a bit by bending them towards the bulb. For the tail lights also unplug and replug the connector and check it's ok.

Give the bulbs the screwdriver treatment too. Also, give each bulb a decent flick with your finger. One really obscure failure mode of bulbs is for the filament to break but then flap about and, when it touches wherever it broke off from, it rewelds itself back together. I had one that I managed to flick it together and also apart several times in succere's aon. So a good solid flick should see a dodgy one off.

One last one; don't forget all the foglights!
 
Oof. This sounds like several hours of work. For the side markers (front fender with BMW roundel) do I need to remove the front wheel, take out the inner fender lining, and reach in to squeeze the tabs to pop the light out, or do I simply turn it counterclockwise and twist it off? I’ve tried twisting/turning it before without any success.
 
MX7 said:
Oof. This sounds like several hours of work. For the side markers (front fender with BMW roundel) do I need to remove the front wheel, take out the inner fender lining, and reach in to squeeze the tabs to pop the light out, or do I simply turn it counterclockwise and twist it off? I’ve tried twisting/turning it before without any success.
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You can actually use a trim tool to pop out the whole surround rather than try to twist the light out of it.
 
okay, and everything but licence plate bulbs apparently :-) Rare for headlight to be monitored see seemingly they do. depends which Google source you reply on.
 
BMWs have had headlight monitoring since Moses was a boy! If by Google you mean the AI summary bit, ignore it completely on all subjects as it's so hallucinatory that it's got to be on drugs. I've lost track of the rubbish I've seen it spit out; it can't repeat fixed tables without rewriting them. Ask it the same question slightly differently and it will contradict itself. Bloody silly thing!
 
I have the same issue on mine. When it throws the light on the dash, I find that one of the indicators on the dashboard goes off/on very quickly as if the bulb was out, but the bulb is fine and after a few seconds the dash is back to normal. I have tried to code out the hot/cold checks using Scanner 1.4, but the problem reappears weeks later and seems to be a different bulb????
 
chanlon1 said:
I have the same issue on mine. When it throws the light on the dash, I find that one of the indicators on the dashboard goes off/on very quickly as if the bulb was out, but the bulb is fine and after a few seconds the dash is back to normal. I have tried to code out the hot/cold checks using Scanner 1.4, but the problem reappears weeks later and seems to be a different bulb????
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A common issue with facelift rear lights is the LED red strips at the top get a high resistance even though they still work. For some reason this then causes the indicators to flash fast, even though they are all working.
Code out the checks to the LED strips and the indicators start working properly again.
 
enuff_zed said:
A common issue with facelift rear lights is the LED red strips at the top get a high resistance even though they still work. For some reason this then causes the indicators to flash fast, even though they are all working.
Code out the checks to the LED strips and the indicators start working properly again.
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Ahhh, never thought of that. A weekend task for me. It only happens every now and again and when the indicators do their quick flashy thing, it only lasts a few seconds before they come back to normal.
 
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