boot opens by itself when driving !

mel_2013 · Post by **mel_2013** » Mon Nov 21, 2016 6:37 pm

hi need some help guys ! My 2011 z4 has decided that it would be great to open the boot by itself when i go to move off ! there is also two led lights constantly lit on the strip light across the boot lid, oh and the boot will not open manually only by using the key fob ! any ideas?

Maniac · Post by **Maniac** » Mon Nov 21, 2016 7:42 pm

Sounds like you have water in the electrics/a short somewhere. DIY take out linings and check or take it to a garage for checks.

mel_2013 · Post by **mel_2013** » Mon Nov 21, 2016 7:44 pm

Thank you ! Am going to take it to my local garage in the morning , hate it when things like this happen.

flybobbie · Post by **flybobbie** » Mon Nov 21, 2016 8:50 pm

Like suggested could be water. I recently had the inside boot liner off. The wires for the boot release micro switch and the led high level lamp are harnessed together just under the boot. Have a look to see if the trim is damp around the warn triangle holder.
Water always drains from the high level area when I lift the boot when it's wet.

The boot release has a micro switch that operates a solenoid, so that possibly stopped working, but the remote operates the same solenoid. If the damp shorts the micro switch, the boot could open itself. Especially recently if salty water has got in.

mel_2013 · Post by **mel_2013** » Mon Nov 21, 2016 11:35 pm

Thanks for your help ! I will pass this message onto the garage to help them ! I would go check what you have said but here in Cornwall it has not stopped raining all day !

Will post an update tomorrow after I get the car back , hopefully it won't have to go to oceans

flybobbie · Post by **flybobbie** » Mon Nov 21, 2016 11:43 pm

Look here at the wiring diagram.
Shows micro switch attached to the emblem badge boot release.
viewtopic.php?f=45&t=91766

Bottom right trunk lid button. (Ignore the squiggly red line).

mel_2013 · Post by **mel_2013** » Tue Nov 22, 2016 5:16 pm

Well I've got the car back today and they couldnt find out what was causing it , they have disconnected the brake light and that seems to have stopped the problem . Have booked it in to BMW .... lets await the bill

Bb5061 · Post by **Bb5061** » Sat Feb 01, 2020 7:19 pm

Hi, what happened in the end with this? I'm having exactly the same problem with my Z4, and I am dreading what it's about to cost me.

StuartH · Post by **StuartH** » Sat Feb 22, 2020 12:59 pm

Same problem started on mine this morning. Any solutions or idea of repair cost ?

Pauly · Post by **Pauly** » Fri Mar 06, 2020 8:21 pm

Last two nights leaving work, I've had to jump out and close the boot. Just checked tonight and noticed my rear top break light is constantly on (but faint) when I move the boot BMW roundel that light goes off, just stuffed a small micro fibre cloth in the space so the battery doesn't run flat. Think this is linked to flybobbie posts as this mechanism seems to control a number of functions. Better learn how to use a soldering iron.

Pauly · Post by **Pauly** » Sat Mar 07, 2020 4:44 pm

Little update, followed flybobbie's post took the assembly out and turns out the wires are fine, no shorts! So I'm left scratching my head now. Basically when I press the break pedal the boot opens, disconnected the top break light and it still does the same, funny enough my rear lights are on without the switch being turned. May have to remove the rear lights to investigate in there. Please if anyone has any other thoughts let me know. Cheers

Pauly · Post by **Pauly** » Sat Mar 07, 2020 7:02 pm

Sorry me again

anyway removed one of my rear lights due to water ingress and whist removing the light discovered a little pool of water beneath the little storage box. Cleaned it all out and fitted a new lamp and guess what, the boot still fuckin opens when I press the brake haha. I have disconnected the top break light as it activates the boot latch, but even if I leave it disconnected, pressing the brake still opens the boot. Any guesses welcome

Pauly · Post by **Pauly** » Sat Mar 07, 2020 7:06 pm

Forgot to add chucked a multi metre on the battery and it's running over 14 volts

Pauly · Post by **Pauly** » Tue Mar 10, 2020 10:38 pm

flybobbie wrote: ↑Mon Nov 21, 2016 8:50 pm Like suggested could be water. I recently had the inside boot liner off. The wires for the boot release micro switch and the led high level lamp are harnessed together just under the boot. Have a look to see if the trim is damp around the warn triangle holder.
Water always drains from the high level area when I lift the boot when it's wet.

The boot release has a micro switch that operates a solenoid, so that possibly stopped working, but the remote operates the same solenoid. If the damp shorts the micro switch, the boot could open itself. Especially recently if salty water has got in.

Flybobbie where is the location of that micro switch (is it attached to the back of the BMW emblem) or is it the two that are part of the assembly attached to the inner boot lid, the ones that you fixed as the wires snapped. Cheers

flybobbie · Post by **flybobbie** » Tue Mar 10, 2020 11:26 pm

Back of the emblem.

Z4-forum.com

Z4-forum.com