2011 Lacrosse Trunk Mysteriously Opens

MHT

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This just started happening to my 2011 LaCrosse with 22k miles on it.

My husband brought it to the car wash and ever since, the trunk randomly opens when it's in the garage with the doors unlocked. Note that we do not carry our key fobs. They remain in the cup holder in the garage, so we can't be pressing it accidentally. We also took both of them and put them out of range and the trunk still opened.

I had the car at the dealer for something else and told him about the trunk opening and after looking at it, said there was nothing wrong. I brought the car home and the next time I went into the garage, the trunk was open. It has not happened when the doors are locked.

I had originally thought we were closing the trunk too hard, causing it to pop back up, but we have been closing it gently and it still does it.

From reading here, the 2 shot relay may or may not work. Considering this started after we had it washed, I'm wondering if something didn't short out.

I'm about to call the dealer back. If this continues, I'm going to sell the car. I don't need this headache. This may also be our last Buick. It's the second defect that's popped up - the first was the GPS fin stopped working for no reason when the car had 2k miles on it. This car is really only used on the weekends. It shouldn't have these problems.
I would have them to install the 2 Shot Relay and replace the Trunk Pad Release and inspect the wire harness at the trunk pad release.
The trunk should not open on its own if the doors are locked but it can. I have not heard back from Buick if there is a permanent fix yet.
 

MaryT

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The dealer clearly said they can not replace anything if the car doesn't produce a code when connected to the computer. This is their standard response. I will go back on Friday but I believe I will be wasting my time unless I tell them I will pay out of pocket. This ain't Lexus. They do nothing for the customer unless the car codes. Note that my dad has the same car - 2010 model with 30k miles on it. He had a fuel injector go bad. They did absolutely nothing for him except charge nearly $900 to replace it.

Am I pissed off? Hell yes. I don't like being dismissed.
 

CarbonBlackCXS

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I will do that, though it feels normal to me.

I got off the phone with the dealer. Even though they had it on the computer last Friday (3 days ago) and it didn't give a code leading them to tell me nothing was wrong, they just told me to bring it back to check it again. I referred them to this forum, and was told that "I can't listen to every person that's on the internet with a car problem."

I asked him to escalate, and all he did was offer to check service bulletins.

I do have to say, I also have a 10 year old Lexus, which I adore, and their service people are a pleasure to deal with. They have fixed countless things for free, all while giving me a loaner.

Never again. This is my second bad experience with Buick for this car and there won't be a third time.
I have no idea what the switch looks like or how water might effect it but the switch is certainly suspect if the the problem started after the car wash. As you pointed out the fobs are left in the car so it would appear your's is a different issue than from what's been previously discussed. Is the dealer aware this problem started after the wash? If you close the trunk does it stay closed or does it pop open right away? If it's caused by a bit of water between the contacts in the switch no they wouldn't get a code and it will feel normal. Water in the switch would cause the switch to perform just as if it were pressed by your hand thus no reason to throw a code. All the water is doing is completing the circuit just as if it were pressed. As for the rubber pad if there's no tear in it water could have also been forced through the edge.
 

MaryT

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I'm not sure if I mentioned it started after the car wash. I will bring it up when I go in.

When we close the trunk sometimes it stays closed and sometimes it doesn't. I thought it was due to closing it too hard, and we had a week of no openings after I closed it gently. However, I did the same last friday and it popped open.

It generally waits about a minute after closing before popping open again. I opened the trunk yesterday, and as of this morning, it was still closed :) We'll see if it remains after I get home.

It does not appear to be consistent.

Thank you for your replies and also thanks to others who are trying to help!
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MHT

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I'm not sure if I mentioned it started after the car wash. I will bring it up when I go in.

When we close the trunk sometimes it stays closed and sometimes it doesn't. I thought it was due to closing it too hard, and we had a week of no openings after I closed it gently. However, I did the same last friday and it popped open.

It generally waits about a minute after closing before popping open again. I opened the trunk yesterday, and as of this morning, it was still closed :) We'll see if it remains after I get home.

It does not appear to be consistent.

Thank you for your replies and also thanks to others who are trying to help!
I guess it depend on the dealer but no codes showed up on my car either. I know that there is a TSB for the replacing of the Trunk Pad Release so no code is needed to have that replaced and the wire harness check. I am not for certain if there is a TSB for the 2 Shot Relay but most are replaced without a code as it is a know problem and not an expensive fix.
Even with all of these repairs I have found my trunk open once five months after the last repair which was the replacement of the Trunk Pad Release. Because the trunk may open on it's own with the doors locked, I believe there may be another issue and only time will tell if Buick/GM comes up with a permanent fix. GM has several models where owners have reported this issue.
My trunk has never opened with in minutes after I close it, it could be weeks or months before it opens on it's own again.

Good Luck............
 

MaryT

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Update

Sorry for the delay in getting back but I couldn't get to the dealer until last week.

We brought the car in for a recall repair and also the trunk issue. We had a different service advisor than the one that told me they couldn't do anything if it didn't code. We told the new advisor the same story and also that *I* had done research and found there was a service bulletin. The first advisor did not even bother to check.

We were told the latch was replaced and from the best I can tell, they installed the new 2 push lock. I tested it and I do have to press the remote twice. The manual button under the trunk also seems a bit harder to press open. So far, the trunk hasn't popped open again, and I intentionally slammed it a few times. We also have to bring it to the car wash again to see if that was the case.

BUT - this time, the advisor informed me that our car was overdue for a 20k mile "throttle cleaning." The car has 22k miles on it. I told him no thank you and checked my owner's manual which made no mention of ever having to clean the throttle. I don't think I've ever had one cleaned on any car I've owned, including the one with 150k miles on it.

I wish there was a dealer a little closer to home because I'd kick these people to the curb. I don't have time nor patience to deal with these jokers and my review of service is going to say as much. I'm honestly on the fence about selling the car just so I don't have to deal with them any longer. Because GM was having so many problems when we purchased the car, we bought the extended warranty (first time ever), so now we're married to this dealership as long as we own the car.

Anyway, thank you to all who have helped out. If the trunk starts popping open again after we wash it, I'll let you all know.
 

CarbonBlackCXS

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Hmmm, I'm not a 100% familiar with all the engines but for 2011 both engine options had direct fuel injection so it likely doesn't have a 'throttle' per se - at least not in the traditional sense where you'd be cleaning off fuel residue. With direct fuel injection the only thing passing over the intake valves is air (there's no fuel mixed with it) so I'm not sure what 'throttle' needs to be cleaned. I'd certainly look into it in more detail before taking the advisors word for it. Most dealerships offer a commission to the advisors for extra work performed so there's good reason to be skeptical.


Edit:
To be somewhat fair to the advisor I found this where a mechanic offered this bit of advice from GM:
"Due to variation in fuel quality in different areas of the country, the only preventative maintenance currently endorsed by GM regarding its gasoline engine fuel systems is the addition of GM Fuel System Treatment PLUS added to a tank of fuel at each oil change."

I have used the AC Delco Port Injector Cleaner I got from GM on a 4.3 I once had and it did help make the engine run better so perhaps the above treatment works similar. YMMV

Read more: http://www.justanswer.com/cadillac/87c6h-cadillac-cts-remove-fuel-rail-passenger-side.html#ixzz3YYNgbwMI
 
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MaryT

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Thank you for that. It will also be included in my review of their service.
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FrogFan

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Well, here we go again! I went out to the garage this afternoon about 3:30 and what did my wondering eyes behold? Yep, the trunk was open!

I was painting around the house all morning with no keys in my pocket at all, so no chance of accidentally hitting the trunk open button (twice, I have the two shot relay) on the key fob. I took a shower, put my key fob in my pocket and went into the garage and the trunk was open!

The last time this happened was in March, so it's not frequent, but it's still a concern. I'm looking forward to any updates on this topic.
 

MHT

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Well, here we go again! I went out to the garage this afternoon about 3:30 and what did my wondering eyes behold? Yep, the trunk was open!

I was painting around the house all morning with no keys in my pocket at all, so no chance of accidentally hitting the trunk open button (twice, I have the two shot relay) on the key fob. I took a shower, put my key fob in my pocket and went into the garage and the trunk was open!

The last time this happened was in March, so it's not frequent, but it's still a concern. I'm looking forward to any updates on this topic.
If they have not done so you may want to ask that they replace the trunk pad release, this is the only other thing that I know of that may help.
 

peacefrog_0521

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I don't know what the fob on the 2011 looks like compared to the 1st-gen (mine is 2007), but I used to have the problem of the trunk and/or panic alarm going off inadvertantly when the button were only lightly pushed; such as fumbling in my pocket, or even when holding in my hand. I finally got tired of it and wrapped several layers of clear cellophane tape around the fob to cover both of these buttons (I left the lock/unlock alone), and now no problems. Requires a slightly firmer push to open the trunk, no delay. I'm ok with that. Suggest you try the same.

Best Regards,
-Raj
 

RonB

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See my post under What is the worst problem with LaCrosse (June 1 or 2, 2016). It has nothing to do with the FOB. Just opening the driver's door opens our trunk 100% of the time. (2012 LaCrosse Touring model). Hundreds of times over years!
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Sosa74

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RonB,

I am having the same problem. My car is a 2012 Buick Lacrosse with less than 100,000 miles and Ive had to replace my FOB after changing the battery(CR2032) on it because my car would not recognize the transponder. I had to get the car towed to the dealership due to the Anti-Theft Deterrent System. The dealership charged me $310.00 for new FOB key. This car has been well taken care of and I plan on trading it in due to the horrible way Buick deals with their factory defects. My trunk opens while driving and when parked and I am forced to leave my trunk empty in fear of getting stuff stolen from it due to this defect.
 

Suz Shortman

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My 2011 Lacrosse has had the same issue with trunk opening when it was parked and not locked. Keeping it locked resolved the issue but today was very weird. Car wouldn’t start like the battery was dead yet radio and ac were operating. Decided to try again and trunk popped open and car started. However, I could not close trunk so only a short ride home with trunk open. Had to hold trunk down and lock car for it to stay closed. Any ideas?
 

Rich B.

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Indeed, the no start sounds like maybe shifter not fully engaged in P or perhaps brake safety intermittent? Trunk opening may be related to battery. Could those remote latches possibly require a constant12vdc at device or otherwise release? Have heard of stranger things, instead of applying power to circuit would require losing it for lock release. Why would it? Have seen very strange things with these cars, nothing can be ruled out...... 🤔
 

Suz Shortman

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Indeed, the no start sounds like maybe shifter not fully engaged in P or perhaps brake safety intermittent? Trunk opening may be related to battery. Could those remote latches possibly require a constant12vdc at device or otherwise release? Have heard of stranger things, instead of applying power to circuit would require losing it for lock release. Why would it? Have seen very strange things with these cars, nothing can be ruled out...... 🤔
The mechanic felt it was a battery issue so we changed it and all is well... It was very odd with the sluggish start or just hearing the starter make that click click click noise, and then windshield wipers would come on, hazard lights... all while neither where turned on. Either way, I'm a happy LaCrosse owner again!
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Suz Shortman

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Well... the trunk has now opened whether the car is locked or not... I've read through the string and am I missing the fix for this issue? It's crazy and annoying as so many in my company call me to tell me my trunk is open... it's getting in the way of my day.
 

jalf

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LaCrosse 2015
Bought my "gently used" 2015 LaCrosse in February '18. On several occasions right away, I opened the garage door and the trunk was open. Figured it had to be connected to the button on the key fob that opens the trunk. I went on ebay and bought a couple "full sealed case chrome key cover shells." One for me, one for the wife. About $26 for both ... from China. Since using the cover shells, the trunk has not opened on its own. I think the heavy-gauge clear plastic over the buttons is what makes the difference. Just stating what worked for me. Sounds like other folks have different issues.
 

Zeroboostbuick

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2018 Regal Sportback - 2010 Yamaha R6 (track bike) Past cars: 92 LeSabre, 98 Regal, 02 GrandPrixGT
Bought my "gently used" 2015 LaCrosse in February '18. On several occasions right away, I opened the garage door and the trunk was open. Figured it had to be connected to the button on the key fob that opens the trunk. I went on ebay and bought a couple "full sealed case chrome key cover shells." One for me, one for the wife. About $26 for both ... from China. Since using the cover shells, the trunk has not opened on its own. I think the heavy-gauge clear plastic over the buttons is what makes the difference. Just stating what worked for me. Sounds like other folks have different issues.

Thanks for your input. I'm sure many will find it helpful.
And welcome to the forum !
 

g_893059

My complaint regarding the sensitivity of the trunk button on the key fob for the 2011 Buick Lacrosse is valid. GM has addressed this same issue in other vehicles for many years now. They have gone so far as to put switches in trunks to prevent the key fob from opening it to significant delays on the key fob switch itself. Someone dropped the ball on this one. If it hasn't happened to you yet does not mean that it won't. Hopefully you will not have anything valuable in the trunk and/or will it be raining. This is a $33,000.00 automobile - not a $200.00 Ipod. I don't think my expectations are too high. Others have the same valid complaint as I.
I am having the same issue. My fob sits on the counter overnight and the trunk pops up in my garage without any intervention. It just started doing this. It also randomly pops up when I pull a door to open it. I have never had a problem with my trunk in 7 years. Now it is popping up sporadically, without intervention, or reason.
 
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