BMW F800 Forum banner

Bulb Warning Light Won't Turn Off

19K views 23 replies 18 participants last post by  Mars13 
#1 ·
I think something odd is happening with my yellow warning light showing a "LAMP" problem.

Three weeks ago it came on, but none of my bulbs were burnt out. Two days later, the main headlight bulb burned out, so I figured the warning light had detected some problem with that bulb, since it did fail a little while after the warning first showed.

I replaced the headlight bulb, and the new bulb works fine. But the yellow warning light never did turn off.

I've ridden the bikes for weeks now, with multiple starts and stops, thinking the sensor would re-set itself. But so far, it hasn't.

There does not appear to be another bulb that is out (or at least none that I can see---is there some mystery bulb on this bike the sensor is reporting?) The replacement headlamp bulb is still fine.

Thoughts?

Would disconnecting the battery force the system to re-evaluate itself and turn off the bulb warning?

Of does the warning light mean there is something funny about the main headlamp bulb circuit, even though the bulb seems to work fine?
 
See less See more
#2 ·
i can only think of the highbeam and parking light possibilities. Disconnecting the bat would reset it yes. there's turn signals, the brake lights, the rear turn signals :/
 
#3 ·
The taillight bulb has two filaments. If one burns out, the bike senses it and uses the other for both functions, so it makes you think that the bulb is OK. If you remove the taillight bulb and test both filaments, you'll probably find one bad. Or you can simply replace it and the bulb monitor will tell you whether you've fixed the trouble.
 
#4 ·
The taillight bulb has two filaments. If one burns out, the bike senses it and uses the other for both functions, so it makes you think that the bulb is OK. If you remove the taillight bulb and test both filaments, you'll probably find one bad. Or you can simply replace it and the bulb monitor will tell you whether you've fixed the trouble.
+1

Had exactly that happen to me - took a while to figure it out!
 
#7 ·
I had this problem a while back. I took my bike into for service on the clutch. The next thing they told me was the headlight assembly is malfunctioning and had to order me a new one. It is not your bulb so you have to ride in highbeam at night to be safe. It is a warranty item.
 
#9 ·
A forum search back to around early 2007 should show that this "bogus" lamp warning when all appeared to be lit was a fairly regular problem. There appeared to be two main causes:-
1] One filament in the twin filament rear lamp had burned out.
or
2] Lack of tension in one or more of the indicator or rear lamp holder spring contacts. The fix was to remove lamp and gently bend the spring blade towards the lamp base to ensure firm contact. On my '07 ST I found that one of the two spring blades in rear holder was markedly pushed back ---- I "tweaked" this and have had no further bogus warnings [but plenty of genuine for dipped headlight! ! ].
 
#10 ·
...or the computer could simply be daft[:p]

[lol] I had my Yellow warning light come on last month, and a [!] beside my odometer figures.

After a few hours, the light went out, but the [!] remained.

I had just hit 6000 km's, so I thought it must be the "to be serviced" thing nagging me.

Then the [!] went away.

Next startup, and the Yellow warning lit up, but this time, my display said LAMP on it, along with the [!] beside the ODO. I was surprised, because it was dark out, and clearly, my low beam/highbeams were working, the parking light, and all my turnsignals, tail/brake lights worked, a very simple verification when it's night time:rolleyes:

Having been aware that the twin filament tail/brake could be "simulated" by the computer if one part was burned out, I swapped it for a known good one, even though that same bulb worked just fine when put in my other bike.

Several rides later, and there are no warning [!] thingies or Yellow lights lit up.

*shrug* who knows. Based on how fawked up my fuel gauge is, I cast a skeptical eye towards any of the other computer related info, aside from possibly the TPM, which I am quite tickled with, despite my initial misgivings[8)]
 
#11 ·
Yep, I had the tail light problem too that I thought was working and wasn't and took awhile to figure out. I just bought a bulb at Walmart and they had a couple choices that I thought would work and I bought the cheap one and it burned out in a short time so bought the more expensive one and it has been fine.
 
#16 ·
I got the LAMP warning on the display during the daytime, yet the headlight and taillight worked. Then when I used the left turn signal and it flashed about 3 x speed. The left front one wasn't working. I took the lens off in a retail store shaded parking lot, removed the bulb and held it up to the sunlight to inspect the filament. It looked perfect and fully formed. Then I noticed the center solder terminal on the bulb was fuzzy/powdery looking. Scraped it lightly on the cement below me to clean it up. Put the bulb back in and it worked! Man, did I feel great! The white turn signal lenses have amber tinted bulbs where the pins aren't opposite each other. They're like 12 and 4 O'Clock positions apart. Not likely to be found at any of the nearby Automotive chain stores. Anyway, at the very next startup the LAMP warning was gone. Cool.

Some weeks later I connected my brand new GS-911blu to the bike and there was something like a "L F turn signal open" warning. Cleared that code and reset the 6K service warning too. The BMS-K CAN-bus is a great system, IMO.

.
 
#17 ·
Hey, THANKS all! I've been riding with the LAMP warning on for a couple of months. Everything worked. After reading this post I swapped in a new tail light, #1157. The warning cleared immediately. No trip to dealer! Yahoo![:D]
 
#19 ·
Mine was the same, tail light bulb worked ok but when you pulled it it had gone darker.
swapped it out and lamp warning went away

CANBUS seems to be able to tell when a bulbs getting close to blowing, although it can be a bugger of a job finding which one it thinks might blow before it actually does
 
#20 ·
It's not detecting a rear filament that's "close to blowing" - it is detecting the fact that the tail lamp filament _has_ blown and is using the brake light filament (at reduced brightness) in it's place. Still clever, but no alchemy involved :)
 
  • Like
Reactions: Runmyownlife
#21 ·
well it looked like both filaments worked (low for tail, brighter for brake) and appeared to be intact - hence my assumption, and that of the service manager.
I've had it on an old 7 series I used to own (fortunately it was bit smarter and told me exactly which bulb it though was duff) in this case it was an indicator bulb that still worked but was darkened. that was the first time I'd encountered such a thing - before that I'd assumed working / not working was the only two states a bulb could be in

Sounds like a clever adaptation if that was what it was doing [:)]
 
#22 ·
Had much the same system on my old 328i, and also on a Peugeot 406. As you observe, on those vehicles the system would tell you which bulb had failed. The OBC on my R12GS is also slightly more informative than the F800 unit, as it shows LAMPR if the problem is with the tail/stop lamp, LAMPF if it's one of the headlamps or the parking lamp, or LAMPS in the event of multiple failures.

Mind you, none of these come anywhere near the system fitted to MAN trucks - on these you press a button and all the external lamps are flashed in sequence, allowing you to check them all during daily walk-around checks.

---
I am here: http://maps.google.com/maps?ll=52.253281,-1.152329
 
#24 ·
I saw this thread and it was just the advice I needed. I also had a headlight blow, replaced it and while I was at it, I replaced the front marker light with a LED that was given to me. Everything worked but the LAMP warning light wouldn't go out. Disconnected the battery. No change. This thread made me recheck all my bulbs, and yes the tail light bulb was probably original, from 2006, still works but the contacts were worn and oxidized.

The other thing I had to do to get the LAMP light to turn off was take out the small LED marker light and replace it with the old standard bulb. Now my CANbus has stopped bothering me! Thanks for the reminder to include bulb maintenance on my list!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top