Defective lamp warning

Hi,

I've been getting an intermittent warning light that is supposed to mean that there's a defective bulb. As far as I can tell though, none of the lights are out.

Any ideas what's causing this? Could it be the beginning of the electrical gremlins when a battery gets old? (I have the original battery and the car's almost 6 years old.)

Thanks!

Rear fog lights?

Originally Posted by kenza

Rear fog lights?

I don't think I have them.

Anyway, it's intermittent, so I think it's some sort of electrical gremlin.

Not sure about the 2007+ with LEDs but on earlier models an intermittent warning of a dead bulb could be:

- a bulb has worked a bit loose in its printed circuit board (vibration from those bumpy roads in the Bay area)

- a bulb has a filament that has just about broken but not quite

I doubt it's your battery - that should be good for another few years unless you have had a few full discharges and/or the magic eye is black.

I got the same message last night when I started my x3 at work. When I got home the warning light went out.

I haven't had a chance to check yet but I suspect one of the bulbs behind the led tail lights on the tailgate has worked loose. I will look at it this weekend. My first thought was it was how cold it was outside yesterday here in NorCal, but I think super is right.

Originally Posted by Supercourse

Not sure about the 2007+ with LEDs but on earlier models an intermittent warning of a dead bulb could be:

- a bulb has worked a bit loose in its printed circuit board (vibration from those bumpy roads in the Bay area)

- a bulb has a filament that has just about broken but not quite

I doubt it's your battery - that should be good for another few years unless you have had a few full discharges and/or the magic eye is black.

Originally Posted by x3brian

I got the same message last night when I started my x3 at work. When I got home the warning light went out.

I haven't had a chance to check yet but I suspect one of the bulbs behind the led tail lights on the tailgate has worked loose. I will look at it this weekend. My first thought was it was how cold it was outside yesterday here in NorCal, but I think super is right.

Do I have LED's or bulbs?

To diagnose and fix this, I'm thinking I just have to wait until it goes completely bad, right now I can't figure out what light's not working even when the warning light is on.

May not be the bumpy roads in the Bay Area, may be because I went off road again last month on a really rough trail.

Originally Posted by spokelizard

Do I have LED's or bulbs?

You have both. I had to take my hatch apart around 50k miles because I had a bulb go out behind the long led lights on the tailgate itself. The traditional bulbs are behind the LEDs and are used for two purposes. 1) force braking 2) rear fogs if you switch out your light switch.

Originally Posted by x3brian

You have both. I had to take my hatch apart around 50k miles because I had a bulb go out behind the long led lights on the tailgate itself. The traditional bulbs are behind the LEDs and are used for two purposes. 1) force braking 2) rear fogs if you switch out your light switch.

Thanks! Didn't know that.

I had the same issue - turned out to be bulb for the red hatch light.

Originally Posted by madurodave

I had the same issue - turned out to be bulb for the red hatch light.

Ah, I don't think I checked that one, I'll take another look. Thanks!

Originally Posted by spokelizard

Ah, I don't think I checked that one, I'll take another look. Thanks!

I did not realize mine was out until I had the dash warning!

I checked the hatch light, no problem. Of course, when I checked the dashboard indicator wasn't lit, hasn't been lit for about 1 1/2 days now.

Originally Posted by spokelizard

I checked the hatch light, no problem. Of course, when I checked the dashboard indicator wasn't lit, hasn't been lit for about 1 1/2 days now.

Mine only flashed on briefly, them stayed off for a long time .

Keep checking, I guess!

Spoke---I thought I would give an update since we both had the issue at the same time....

The intermittent out light for me was the passenger side rear bulb brake/tail light below the led tail light. It's behind the right access door and its the bulb housing that pulls straight up. I just needed a new w16w bulb. I picked up a 2 pack at napa for $4.85. I bought the equivalent base type at napa marked 921LL.

I ve had that warning light on for the past 500 days.

Gave up on searching... all the lights that I know of are on.

It's funny you say that...my warning lamp came back in Tuesday morning...

It is now the bulb I originally suspected. It is one of the force braking bulbs in the hatch behind the led lights. I suspect the bulb is fine, but it has worked loose from the bulb housing/circuit board from opening and closing the hatch.

Unfortunately this bulb is a bummer to get to.

I had a similiar issue with my 528i a year or more ago.
Check the brake light on top of rear visor.
Did it go out when the brakes were applied?

Reel Job

2007 X3
1998 528i
2011 R1200RT

Originally Posted by sjladopoulos

I ve had that warning light on for the past 500 days.

Gave up on searching... all the lights that I know of are on.

If you have ruled out the brake force display by having someone watch as you brake sharply from high speed, it could be a (marginally) working bulb with high resistance.

From what I understand, the dealer's fancy diagnostic equipment applies a test voltage to look for high resistance.

The high resistance might be accompanied with a blackened glass, or just a loose or corroded connection.

The only DIY recourse is to start swapping in new bulbs for the seemingly good ones until the warning light goes away - or just replace them all anyway.

Originally Posted by x3brian

It is now the bulb I originally suspected. It is one of the force braking bulbs in the hatch behind the led lights. I suspect the bulb is fine, but it has worked loose from the bulb housing/circuit board from opening and closing the hatch.

Originally Posted by Supercourse

If you have ruled out the brake force display by having someone watch as you brake sharply from high speed, it could be a (marginally) working bulb with high resistance.

Well I haven't had the warning light for about 5 days now. Don't know whether that's a good sign or a bad sign though.

What I'm understanding from X3brian and Supercourse is that there's a filament bulb behind the LED display that is the force braking indicator. I'm not sure I've really checked that out. I assumed the light would vary in intensity as I increased my force on the brake pedal when the car is parked, and that's what I tried to test. But Supercourse is saying you really have to do a fast stop from high speed, which I'm really not going to try to test.

I'm understanding that there is a filament bulb behind the LED display wherever the brake lights are, so on the left and right in the main rear light assembly, and in the center higher up on the tailgate. Anywhere else?

I just had my wife hit the brakes hard while the car was idling in the garage. The left one lit up but not the right.

I had this problem once, bulb indicator light on but couldn't find a bad bulb....turned out to be one of the license plate bulbs that was out (hard to notice), so make sure to check those li'l suckers too

I had checked ALL of them and I know which one (of two) it must be.

Its one of the rear fog/hazard brake lights.

When the indicator first came on, I looked at all the bulbs, didnt find anything, told my wife to drive on the HW at 120 and slam the brakes so I can see while following her in our Accord what is going on.

Apart from almost ramming into the X3 cause the brakes on the Accord are nowhere near as good as in the X3, I barely had time to notice that no extra light came on.

So there you go.. the only bulb that is a to get is out...

Conclusion? Do not get an Accord!!!!!

Originally Posted by djayblanco

I had this problem once, bulb indicator light on but couldn't find a bad bulb....turned out to be one of the license plate bulbs that was out (hard to notice), so make sure to check those li'l suckers too

Well, that's another one I haven't checked! And I thought I looked at them all, but there seems to always be one more.

Originally Posted by sjladopoulos

I had checked ALL of them and I know which one (of two) it must be.

Its one of the rear fog/hazard brake lights.

When the indicator first came on, I looked at all the bulbs, didnt find anything, told my wife to drive on the HW at 120 and slam the brakes so I can see while following her in our Accord what is going on.

Apart from almost ramming into the X3 cause the brakes on the Accord are nowhere near as good as in the X3, I barely had time to notice that no extra light came on.

So there you go.. the only bulb that is a to get is out...

Conclusion? Do not get an Accord!!!!!

Don't think I have rear fog lights. How do I know for sure?

Glad you didn't rear end your own car, that would be a hard one to explain to insurance! That's why I prefered to check the "force braking" just parked in my driveway.

Originally Posted by spokelizard

Don't think I have rear fog lights. How do I know for sure?

Glad you didn't rear end your own car, that would be a hard one to explain to insurance! That's why I prefered to check the "force braking" just parked in my driveway.

The fog light are there, here in N.A we dont have a switch to operate them as fog lights, and they are configured to work when the ABS kicks in (stage 2 brake lights).

How can you inspect that on the driveway? That is why I wanted highway speeds..

Thankfully I kept my distance and I knew what was gonna happen

Yes, it needs a deceleration in excess of 15 ft./sec. to activate the brake force display - that is, when a briefcase goes flying off the seat, or your dog in the back thumps into your headrest.

Wouldn't there be a safer way to check its functioning?

Such as, you in the other car pull off onto the shoulder, and have the X3 come by at the speed limit and brake sharply just after it passes you.

But then it's up to the X3 driver to time things so that there isn't someone anywhere in their rear view mirror.