[SirNicholas]

Please help! My trunk swings OPEN as soon as I click and hold the Start button for the car to turn on! Throughout the day, each time the car was off and I pressed and held the start button the trunk opened on its own. Car was fine last week and has been parked without being driven for about 5 days as I was out of town.

I manually tested the scenario and the trunk opened again on its own. Then I tested with the "trunk lock switch" on, and the trunk didn't open, so at least that works. I'm going to keep it lock on overnight to be safe.

When I got home, I pulled up to my parking spot, put the car in reverse and boom the trunk swung open again!

Is this known? I am scared the trunk might open while driving or worse when it is parked overnight. This means I can't store anything in the car! At first I thought it was directly tied to the starter, but putting the car in reverse caused the same issue, so I'm scared it may be an electrical issue. Unfortunately, the car is out of warranty (2011 F10 535i).

[SirNicholas]

No one?

[NV GUNS]

Originally Posted by SirNicholas

No one?

maybe one of the ECU files somehow got corrupted, it does happen. best bet it is to take it the the dealer and have them reload the ECU files. Or could be the key fob. I would talk to the dealer asap because that is a safety hazard.

[graphite]

I work for a dealer that's got a '14 M5 currently in the shop for the exact same issue. I'll let you know what they find.

[BMWrules7]

Originally Posted by SirNicholas

Please help! My trunk swings OPEN as soon as I click and hold the Start button for the car to turn on! Throughout the day, each time the car was off and I pressed and held the start button the trunk opened on its own. Car was fine last week and has been parked without being driven for about 5 days as I was out of town.

I manually tested the scenario and the trunk opened again on its own. Then I tested with the "trunk lock switch" on, and the trunk didn't open, so at least that works. I'm going to keep it lock on overnight to be safe.

When I got home, I pulled up to my parking spot, put the car in reverse and boom the trunk swung open again!

Is this known? I am scared the trunk might open while driving or worse when it is parked overnight. This means I can't store anything in the car! At first I thought it was directly tied to the starter, but putting the car in reverse caused the same issue, so I'm scared it may be an electrical issue. Unfortunately, the car is out of warranty (2011 F10 535i).

1. Lock the trunk with the internal switch at night and you should be safe until it's fixed.

2. Change both batteries on both key fobs.

If it still happens after changing both key fob batteries, then do this:

1. Remove the new battery from one of the fobs and put it in your house.

2. Test the other fob (with new battery) and see if trouble goes away. (If trouble only with 1 fob, replace fob or don't use it for a while) (make sure trunk switch not defeated).

3. If not, take the battery out of the fob that was just tested and put new battery in other fob and repeat test.

4. If still failure, then you ruled out the fobs.

5. Confirm vehicle battery is good. Whacky things happen when electronics face under-voltage
.

[Stück]

Almost certainly a faulty FOB.

Pull the battery out of your key fob and hold it up to the column to start the engine. If the trunk doesn't pop open replace the battery and start the car again. If it pops open... the problem is the fob.

[EL Jeffe 5]

This was happening on my friends 2008 BMW 535 Trunk keep opening on red lights
He replaced battery NOT FOB battery

[SirNicholas]

I'll test both key fobs tomorrow, but I honestly doubt that's the issue because the opening of the trunk is directly related to an action in the car (and not a random occurrence).

I'll take it to the dealer as a last resort. I need to replace the tension springs as well. Right now, the trunk swings open really fast

Originally Posted by graphite

I work for a dealer that's got a '14 M5 currently in the shop for the exact same issue. I'll let you know what they find.

Thanks! Please let me know what you guys discover. I really appreciate it.

[SirNicholas]

Originally Posted by Stück

Almost certainly a faulty FOB.

Pull the battery out of your key fob and hold it up to the column to start the engine. If the trunk doesn't pop open replace the battery and start the car again. If it pops open... the problem is the fob.

I don't think I understand. How will the car start without a key fob?

[Trian]

As you sit in the driver's seat, look down on the RHS of the steering column and you will see a stylized drawing of a key. The manual says to place your key fob there against that drawing to start your car (using the start button then), it the battery key fob is low (i.e. so low that your car doesn't recognize that you have the key fob).

[graphite]

Dealer is claiming it's a faulty key fob and has a replacement on order. Should be completed on Wednesday, will update with more information then.

[Stück]

Originally Posted by graphite

Dealer is claiming it's a faulty key fob

Ding Ding

[SirNicholas]

Originally Posted by graphite

Dealer is claiming it's a faulty key fob and has a replacement on order. Should be completed on Wednesday, will update with more information then.

Music to my ears!

I tried my second key fob today as well and the trunk didn't open, but it was a limited test only.

I'll try using the second key fob the whole day tomorrow and see if I can replicate the issue.

[graphite]

Originally Posted by Stück

Ding Ding

Originally Posted by SirNicholas

Music to my ears!

I tried my second key fob today as well and the trunk didn't open, but it was a limited test only.

I'll try using the second key fob the whole day tomorrow and see if I can replicate the issue.

Well, looks like the key didn't correct the issue. They got a brand new fob all programmed to the car and got rid of the old one, then right as the car was brought around to get written up, the trunk opened itself again...

Back to the drawing board we go.

[Stück]

Awww shit lol.

[Acturater]

Null

[Acturater]

This exact thing happened twice on the same day in my F80 M3 last week. I'm in the Northeast US and we've had a stretch of warm weather lately. The thing about warmer weather here is it comes and goes so you gotta be prepared, i.e., still carry a jacket with you. So on that day I left home with my jacket on because it was colder in the morning and had my keys in one of the pockets, but towards the afternoon the temps rose to the mid-70s so I took the jacket off. I'd normally put the keys in the front pocket of my shirt out of habit but the shirt I was wearing that day didn't have one. Luckily I have a carabiner on my keychain for just that situation so I can hook it onto one of the belt loops on my trousers. Well, the trousers I was wearing that day was the one pair where the belt loop on the right side is a bit further back. Being right handed, that loop was where I decided to hook the carabiner along with the keys. Now fast forward to the moment I got into my car, sat down, and hit the ignition - well wouldn't you know it the trunk immediate pops open. Puzzled, I got out of the car with the ignition running to close it - I should mention at that point I noted just how loud the exhaust was from the outside especially because I only drive the car on Sport Plus throttle and like to keep the valves open. That explained the stares I'd get from time to time in the parking lot around work. Anyhow, thinking the problem was a fluke I drove to my next destination, which was a Bank of America ATM to pull some cash. After I pulled the cash I got back in the car, turned the ignition on, and voila! the trunk pops open again! Now at this point I'm truly puzzled. Then inspiration hits - I'm reminded of the time I took the car into the dealership for, among other reasons, the car alarm going off out of nowhere and just blaring the entire time I'm driving down the highway! On one such occasion I recollected having to pull into the gas station to address the issue, all the while an idiot in the car next to me yelling "HE STOLE IT! HE STOLE IT!" His buddy was looking the other way trying to ignore the idiot he chose as his friend and accomplice. In any case, back to what I was saying, I dismissed the service advisor at the time chalking the problem up to a software glitch, for which incidentally I had requested an update to the latest version; however now the advisor's explanation didn't seem so far fetched. So going back to that warm day in Northeast USA, I was happy to report the issue disappeared once I placed the keys less accessible by my hind quarters. I hope this lends at least an inkling of help towards your quest to find a resolution.

[SirNicholas]

Originally Posted by graphite

Well, looks like the key didn't correct the issue. They got a brand new fob all programmed to the car and got rid of the old one, then right as the car was brought around to get written up, the trunk opened itself again...

Back to the drawing board we go.

Yeah, I have some bad news as well. After successfully testing my backup key fob, I switched back to the original to try and reproduce the issue again and for the life of me can't anymore. It has fixed itself!

I know for a fact it is not me pressing the trunk button on the keyfob by accident because A.) the opening is synced with either hitting the ignition or B.) putting the car in reverse. I've successfully reproduced the issue with each of these scenarios (back when the issue was reproducible) with the key fob on the passenger seat next to me.

I have a few ideas at this point:

1.) There is a loose wire somewhere (perhaps rodents damage?)
2.) I had a discharged battery issue on the first day after I was back from vacation (6 days of not driving), but since then the car has properly recharged itself. I could still get the battery tested to rule this out
3.) No friggin clue!

[voona]

Have you checked wiring loom that goes from car body to trunk? BMWs are notorious for problems with short circuit in this wiring loom.

[graphite]

Following up, the dealership has now ordered what they referred to as an "aerial controle module" that apparently handles keyless entry and SRS functions. Was told it's in the headliner near the sunroof controls. We shall see.