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Discussion Starter #1
Hello all! Newbie here. Recently bought a 2007 X3 for my kids for their first car. Both just started driving. The X3 has 129k on it Was very well kept. My son and I have already replaced the valve cover gasket and servo actuator gear. I new it needed the valve cover gasket but the gear was a surprise on us but it was a pretty easy fix. The issue at hand is the brake lights. My main question is this; Is the third brake light (light bar on top center) supposed to work under normal braking? I have read mixed reviews on this light. Some say it only works under extreme braking, others say it only works as a back up when the 2 outer brake lights go out. Very confused here. Last night my daughter said the brake light indictor came on on the dash board. My son and I went out to take a look and found that the driver side outer bulb was out and the passenger side inner bulb was out. After replacing the drivers side outer I found that now BOTH inner bulbs were not working. After playing around with it and thinking for a while I realized that the 2 inner bulbs (located on the tailgate) are only back up bulbs for when the outer ones go out. Again, very confusing.

So, after all that the only brake bulbs that come on under normal braking are the 2 outer lights. That's it. IS this correct or is the third brake light bar supposed to work as well.

Any help and info is much appreciated!!

Thanks, Chris
 

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post 4 from this FESTCHIVE link

>there have been wiring issues etc ....post 4 is a good start .....also attaching the links for videos/parts and your electronic online owners manual that will be useful

>best wishes

http://www.bimmerfest.com/forums/showthread.php?t=758072

>online manual

http://workshop-manuals.com/bmw/

>online how to videos

http://www.bmwusa.com/Standard/Cont...ideoguid=9aeda1e8-a3f0-4619-8b21-adc9b8db0ee5

>online REALOEM.COM parts ....just put last seven of your VIN in and voila ....all your exact stuff

http://www.realoem.com/bmw/select.do?vin=Wc31579
 

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let there be light...brake light

>some more light on the subject

https://www.google.com/search?client=safari&rls=en&q=bmw+2+stage+brake+lights&ie=UTF-8&oe=UTF-8

>post 4 ....http://www.xoutpost.com/bmw-sav-forums/x5-e70-forum/95491-right-two-stage-brake-lamp-warning.html
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The second stage won't come on unless the ABS is engaged while braking. There are little access panels on the trunk hatch to access the bulbs
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'09 X5 35D - | CIC + Combox + LCI Headlight/Tail light retrofit | ECE Mirrors + Rear Foglights | X5M front brakes | FLA retrofit |
 

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........ My main question is this; Is the third brake light (light bar on top center) supposed to work under normal braking? I have read mixed reviews on this light.
Don't think there is any confusion on this. The hi-mount brake light should work under normal braking.

Your LED strip needs looking at, or the connection to it.

(And it sounds like you have something wrong with other bulbs in the corners & tailgate.)
 

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The outer bulbs and CHMSL (Center High Mounted Stop Light) should come on during normal braking.

As said, the inner bulbs come on when you engage ABS while braking.

Sent from my XT1650 using Tapatalk
 

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Discussion Starter #6 (Edited)
Thanks for the replies? I tried replying yesterday but the site would not let me......

Anyways, why would I not get a light on the dashboard to come on to indicate that the CHMSL light is out? Any way I can test it to see if it is the light bar or another issue going on causing it not to come on?
 

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Pop the light off and apply power, see if it turns on.

This will also give you the chance to use a multimeter or test light on the exposed wiring to see if you have power with the brake pedal depressed.

Pretty basic stuff.

Sent from my XT1650 using Tapatalk
 

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Discussion Starter #8
Ok, I have no power to the brake light at the connection point in the liftgate. Might there be a fuse that controls this circuit?
 

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From experience with Jeep XJs and their notorious wiper and 3rd brake light (mandatory since 1986) failures, check the condition of the wires inside the loom where it passes from the body into the hatch. On XJs, the wires are notorious for cracking from age and fatigue inside the rubber boot which appears in fine shape from the outside.

There is of course a fuse, but would probably have the other brake lights on it. If popped, it popped for a reason, perhaps a short mentioned above.

As for the other issues, it is a bad bulb or socket. The inner (hatch mounted) brake lights come on under emergency braking but also illuminate when an outer brake bulb has failed. Check outer bulbs and clean the contacts. A bulb may be loose.
 

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Digest these pearls of wisdom first:

The lighting system is way more advanced than you think. It uses a computer to monitor the filament both hot and cold and strobe the bulbs to maintain the brightness as the supply fluctuates and can repurpose nearby bulbs for safety features in the event of a failure. There's unlikely to be a traditional fuse-per-bulb. If a single bulb is out then you should have a warning on the dash and the faulty bulb should be replaced.
If you don't have a warning light on the dash, perhaps the sophisticated computer can't check the LEDs quite so easily. As suggested by the links posted by swampx3, try looking for a broken wire where they go into the rear hatch/door. Opening and closing the rear hatch over time could flex these enough to break.
 

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The High Level brake light is unique in that it's an LED strip. The individuals lamps are not replaceable and it won't support hot or cold monitoring.

As above, check for frayed wiring where it passes through the metal of the car from the body to the trunk lid.
 

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Discussion Starter #12
ok, so I checked out the wiring through the hatch and it's all good. I'm not getting power to the light. I hooked up a 9v battery to the light and it came on so the problem is from the top on the roof where it goes into the body somewhere. I check all the fuses in the glove box and they are all good. Not sure where to go from here....Anybody have any thoughts?
 

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My thought would be...

To ignore it. Don't go down that rabbit hole.

Sent from my XT1650 using Tapatalk
 
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