[thestuarts]

There are multiple threads discussing the random trunk opening problem:

Random Boot/Trunk Opening

What's wrong with the trunk???

Random Trunk Opening - happened to you?

Update: know the cause now! 2019 X3 tailgate opened suddenly during highway driving


I dropped off my 2019 M40i at the dealer on February 25, 2019. I showed them the video of the trunk opening and closing on its own. The service manager agreed the trunk should not do that.

They took the bumper off and did some diagnostics.



The service technician "found antenna intermittently shorting causing smart open control module to fail."



They ordered the following parts:

• Control Unit for Smart Opener
• Sensor Wire for Smart Opener
• Sensor Wire for Smart Opener
• Expanding Rivet

It took 10 days for the parts to arrive, and it only took them 1 day to install the parts and reattach the bumper. The car was returned to me on March 8th, 2019.

You won't believe what happened next. The lot attendant pulled the car out of the garage and parked it in the customer pickup area. He handed me the key, then I walked toward the vehicle with they key held flat in my open hand so I wouldn't accidentally push the trunk button. As I approached the vehicle, the trunk opened on its own! I stood still in disbelief. I turned and asked the lot attendant if he saw the trunk open on its own. He said he did. As we were standing there, the trunk closed on its own!

Obviously, the repair did not fix the problem.

However, I did notice something that may be relevant. The vehicle was wet because the dealership just gave the vehicle a courtesy wash. To the best of my recollection, the problem only happens to me when the vehicle is wet.

If you are experiencing the random trunk opening problem, I do I'd like to know if you can recall if the problem only happens when the vehicle is wet or is possibly covered in snow/slush that is melting.

[Lux700]

That must be very frustrating as well as a huge inconvenience. Clearly nothing they changed made any difference which means they’re back to the drawing board. Hope they sort it for you soon.

[RegieX]

glad they actually found the cause.

[HollyM]

thestuarts,

YES! This has happened to me twice and BOTH times I had just hand-washed the car and was drying it - far away from the liftgate and with the fob lying motionless on a garage shelf far away from me.

We are in the same boat. I've not had the time to address it, so I'm just drying it and detailing it outside my garage, so as to avoid any damage when it starts this unexplained malarchy.

EDIT: My vehicle was unlocked in both instances, as I was drying it (and of course was drying door sills, jambs, interior glass, etc). Just wanted to be clear that my vehicle was not locked when this occurred.

[MechX3M40i]

I'm wondering if there is some kind of pathway of water ingression to the sensors to cause this to happen? Maybe some better seal would do the trick?

Frustrating that this happens to some unlucky people but not to everyone?!

[BMWZ4]

Originally Posted by RegieX

glad they actually found the cause.

I think the OP is saying that, despite the work the issue has not been resolved.

[stein_325i]

Is this only an issue with the X3, or have any X4 owners noticed it as well, or even X5 owners too?

[titomi]

Originally Posted by MechX3M40i

I'm wondering if there is some kind of pathway of water ingression to the sensors to cause this to happen? Maybe some better seal would do the trick?

Frustrating that this happens to some unlucky people but not to everyone?!

If it's related only to wet conditions (not sure whether it is), than it could be possible, that only some are experiencing the issue. Might be some bad alignment of seal, or missing seal. Manufacturing error.

[supersebbo]

Well this will only add to the confusion, but mine was not related to wet conditions. However the fix they did was the same, mostly. They diagnosed a fault with the sensor unit which was triggering the trunk release. They replaced just the controller unit and it appears (so far) to have fixed it.

[Gary pa28]

If I had that much trouble with the kick opening , I would disconnect it and be done .
Just use button /key fob

[JayPichardo]

This has never happened to me but I want to keep an eye on this.

[MechX3M40i]

In addition to faulty sensor, I would suggest OP check the key fob too just in case it got a 'stuck key' on the trunk button. This can be experiment to compare if both key fobs do the same to allow the trunk opens/closes itself when in proximity to the car.

[No1Cares]

maybe you're abusing your x3 and it is trying to cry for help in a secret way. that's probably the real issue.

[thestuarts]

Originally Posted by MechX3M40i

In addition to faulty sensor, I would suggest OP check the key fob too just in case it got a 'stuck key' on the trunk button. This can be experiment to compare if both key fobs do the same to allow the trunk opens/closes itself when in proximity to the car.

I have never used the trunk button on the fob. Come to think of it, I have never used any of the buttons on the fob. I just carry the fob in a hard protector and use comfort access to get in and out. I open the trunk by pressing the button under the BMW logo, or I occasionally use kick to open.

However, your point is valid. The fob could still be experiencing a malfunction. I will discuss this with the dealer because they did not mention troubleshooting the fob. Thanks!

[thestuarts]

Originally Posted by Gary pa28

If I had that much trouble with the kick opening , I would disconnect it and be done .
Just use button /key fob

Gary, I am considering disabling kick to open.

I do want to clarify that I am not frustrated with this particular problem. I love the vehicle, even with the trunk problem. I write software and firmware for a living, so I can be understanding and patient while the bugs are worked out.

[thestuarts]

Originally Posted by supersebbo

Well this will only add to the confusion, but mine was not related to wet conditions. However the fix they did was the same, mostly. They diagnosed a fault with the sensor unit which was triggering the trunk release. They replaced just the controller unit and it appears (so far) to have fixed it.

That's good information, thanks!

[BMWZ4]

I'm wondering if mine is fine because I have the factory tow hitch, therefore no kick-to-open feature

[XGoober]

thestuarts Thanks for posting your ongoing experiences with this. I'm awaiting delivery of my M40i and I'm unsure what to do about all this. My biggest concern is this will happen while going through a carwash. The damage could be very bad in that case and I don't fancy trying to fight with BMW to pay for it.

So far I think I have seen a couple of potential workarounds posted.

1. Have the dealer code the car so that the trunk will never open when the car is locked
2. Have the dealer disable the kick-to-open feature (at least I'm assuming that is a dealer code option?)

Anything else that can be done? I know neither of the above are ideal as we lose functionality in either case.

[HoustonEaDo]

Originally Posted by XGoober

thestuarts Thanks for posting your ongoing experiences with this. I'm awaiting delivery of my M40i and I'm unsure what to do about all this. My biggest concern is this will happen while going through a carwash. The damage could be very bad in that case and I don't fancy trying to fight with BMW to pay for it.

So far I think I have seen a couple of potential workarounds posted.

1. Have the dealer code the car so that the trunk will never open when the car is locked
2. Have the dealer disable the kick-to-open feature (at least I'm assuming that is a dealer code option?)

Anything else that can be done? I know neither of the above are ideal as we lose functionality in either case.

You will more than likely not have the issue...this is only happening on a handful of vehicles and is a pain for those owners....

[XGoober]

Originally Posted by HoustonEaDo

You will more than likely not have the issue...this is only happening on a handful of vehicles and is a pain for those owners....very little chance your vehicle will have the issue

I wish I could share your confidence. I started a poll a little while back, asking who had experienced the problem. Almost 30% responded that they had. I'm not sure 30% is low enough for me to just keep my fingers crossed.

https://x3.xbimmers.com/forums/showthread.php?t=1588303

[HoustonEaDo]

Originally Posted by XGoober

I wish I could share your confidence. I started a poll a little while back, asking who had experienced the problem. Almost 30% responded that they had. I'm not sure 30% is low enough for me to just keep my fingers crossed.

https://x3.xbimmers.com/forums/showthread.php?t=1588303

It's definitely something to keep in mind and check when your vehicle arrives - remember forums have way more complaints than compliments - most people don't come to forums unless they are having issues looking for a solution so it will seem like all the vehicles are pieces of junk - far from reality though....

Your poll showed almost 30% of people who responded are having the issue - that is not the same as 30% of X3's having the issue...

[MechX3M40i]

Originally Posted by XGoober

I wish I could share your confidence. I started a poll a little while back, asking who had experienced the problem. Almost 30% responded that they had. I'm not sure 30% is low enough for me to just keep my fingers crossed.

https://x3.xbimmers.com/forums/showthread.php?t=1588303

Did your poll differentiate the trunk opening due to faulty sensor vs. inadvertent key fob pressing? My impression after reading most of the posts is that the faulty sensor is a lot less common vs 'butt dialing' the key fob.