2011 Lacrosse Trunk Mysteriously Opens

dbris

Full Member
163
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18
Los Angeles
Buick Ownership
2011 Lacrosse CXS
Same problem here. I don't remember it ever doing it before the double click relay was installed. It's as if the latch stays open not closed, because the lid goes all the way down, and if the latch were closed it would stick up a bit. It's not a major problem - once a month or so, and I can live with it. MUCH better than it opening on it's own!
 

wick5449

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western, NY (not NYC)
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Buick LaCrosse
My 2011 LaCrosse trunk has opened on several occasions. This past week we were on the other side of town and both remotes were with me. My neighbor called on my cell phone and told us our trunk was open and it was raining. Until now I thought we were hitting the remote by mistake. Now know that is not the case and also do not think the remote range would reach for many miles, since we were several miles from home.
Hi, just joined the forum. Had the same problem. Looked into the release button on my 2011 LaCrosse, under the trunk lid, found moisture got to it and it was all sorts of green and blue. Replaced entire lock unit with one that takes two distinct pushes of button or fob, just to eliminate the possibility of a single tray impulse. So far all is well. It was happening once or twice a week, now it's been two weeks and no openings. Hope it continues. I have low miles and it is under the four years. Buick covered it. The service manager said they had no Buicks in with this problem, but had some chevys and cadillacs with similar devices going bad.
 

mtscjordan

Buick Newbie
3
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Westford, Mass
Buick Ownership
2011 Buick Lacrosse
I am experiencing the same thing - not sure why - 161k miles on vehicle. I started car today, then it opened up - mine is the push button cxl version. It seems transmitter related - thought it was the cold weather, but now not sure?
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mtscjordan

Buick Newbie
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Westford, Mass
Buick Ownership
2011 Buick Lacrosse
I posted before, I have started to lock car and think that may help or cure issue - this would indicate the switch on the trunk, not the transmitter. I'll update soon,
 

MHT

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Indiana
My thread, New Trunk Release Relay also deals with this and other issues concerning the Mysterious or Random Trunk Open.
I have an open investigation with the Buick Executive Office and am waiting to hear back from them next week. I have been pursuing this issue for over a year now. This problem also existed on the 2012 Buick LaCrosse PII that I traded for the 2014.
 

MHT

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I posted before, I have started to lock car and think that may help or cure issue - this would indicate the switch on the trunk, not the transmitter. I'll update soon,
This problem could be caused by the circuit that allows the trunk to be locked and unlocked by the key fob. If the doors are locked you can not open the trunk with the Key Pad Release so any short in that release is not going to cause the trunk to open when the doors are locked but a short in the circuit that allows the trunk to be locked and unlocked with the key fob could.
If the trunk opens and the doors are locked than Buick needs to check the circuit that allows the trunk to be locked and unlocked by the key fob and in the case of the 2014, the trunk release on the door also, which may also be on the same circuit.
 

WWS

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Buick
This problem could be caused by the circuit that allows the trunk to be locked and unlocked by the key fob. If the doors are locked you can not open the trunk with the Key Pad Release so any short in that release is not going to cause the trunk to open when the doors are locked but a short in the circuit that allows the trunk to be locked and unlocked with the key fob could.
If the trunk opens and the doors are locked than Buick needs to check the circuit that allows the trunk to be locked and unlocked by the key fob and in the case of the 2014, the trunk release on the door also, which may also be on the same circuit.
On my 2015 my trunk will open with the fob or the pad on the trunk lid even if the doors are locked.
And the doors stay locked.
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MHT

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On my 2015 my trunk will open with the fob or the pad on the trunk lid even if the doors are locked.
And the doors stay locked.
If you doors are locked you should not be able to open the trunk with the Trunk Key Pad Release on he trunk, unless the key Fob is in very close range of the car.
 
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rsveach64

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2012 Buick Lacrosse
I have a 2012 Lacrosse, and I have a similar problem; every once in a while, after I get in the car, I have to get back out to close the trunk.

I think the computer is opening the trunk on some occasions when I push the unlock button on my key fob. It's aggravating to have to get out of the car, after I've already gotten situated and my belt buckled.

So now, I always walk behind the car to get in, and I test the trunk lid to see if it opened this time when I unlocked the door. Probably once out every 6 or 8 times I find the trunk open.

I just live with it.

Scott
 

MHT

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Indiana
I have a 2012 Lacrosse, and I have a similar problem; every once in a while, after I get in the car, I have to get back out to close the trunk.

I think the computer is opening the trunk on some occasions when I push the unlock button on my key fob. It's aggravating to have to get out of the car, after I've already gotten situated and my belt buckled.

So now, I always walk behind the car to get in, and I test the trunk lid to see if it opened this time when I unlocked the door. Probably once out every 6 or 8 times I find the trunk open.

I just live with it.

Scott
Have you had the dealer install the 2 shot relay? If not you may want to give it a try. You should be able to get it done under warranty.
 

MHT

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As of this date I have not heard anything back form the GM Executive office about any updated repair for this issue. I have done some more research and found that with the GM Brand this issue seem to be most common with the LaCrosse,Regal,Cruze and XTS.
It was also interesting to see that some of the same customer service reps replying to this thread also replied to the same thread concerning the other models. That lets me know that this issue is no secret but very well known. One owner mention his dealer put a solenoid in the car to by pass the trunk locking system, the trunk has not opened but the disadvantage is he has to hit a switch to disengage the solenoid before he can open the trunk.
I was surprised to see that there were other brands both domestic and foreign where owners have reported the same issue, may be this is the reason that GM does not seem to be in a mad rush to get this problem resolved or they may not have a clue has how to address it but I do, just bring back the simple trunk opener of old, 70's-80's.
The only relief for me is it seem that the trunk is not opening if the doors are locked but I am still monitoring to see if it will.
I am still interested in the 2016 LaCrosse but I hope this issue will be resolved by the time it hits the show room. It looks like the 2016 will have the regular size A Pillars which should improve the front side view and a larger trunk. The exterior and interior of the 2016 also look pretty promising.
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FrogFan

Full Member
137
10
18
Ft. Worth, TX
Buick Ownership
2013 LaCrosse
About two weeks ago, I went into my garage and found my car's trunk open. I have a 2013. This happens very rarely for me, but it's still disconcerting. I have the two-shot relay installed. My car was locked in the garage when the trunk was open. The last two times I found my trunk open (since I got the two-shot relay installed), it was in my garage.

It is possible that I accidentally hit the trunk open button twice while I carry the fob around in my pocket, especially since I've only found the trunk open in my garage, but it seems unlikely with the two-shot relay.

I'm still very interested in a resolution to this issue.
 

MHT

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About two weeks ago, I went into my garage and found my car's trunk open. I have a 2013. This happens very rarely for me, but it's still disconcerting. I have the two-shot relay installed. My car was locked in the garage when the trunk was open. The last two times I found my trunk open (since I got the two-shot relay installed), it was in my garage.

It is possible that I accidentally hit the trunk open button twice while I carry the fob around in my pocket, especially since I've only found the trunk open in my garage, but it seems unlikely with the two-shot relay.

I'm still very interested in a resolution to this issue.
Thank you for your reply. I would like permission to copy and send to the GM Executive office. I too believe that I have experienced the random trunk open with the doors locked. I also have the two shot relay as well as a new trunk pad release. The reason your trunk is only opening on rare occasions is because of the two shot relay. If you had the standard relay it would be more frequent.
I believe the problem is in the module/ circuit that controls the door locks and trunk from the key fob. There has to be a short or a pulse that is being sent out that is causing the trunk to open from that source, as the trunk will not open if the doors are locked and you try to open the trunk by the key pad release, this means that the problem is not in the key pad release.
With the two shot relay that signal has to go out just as if you were pressing the key fob and it does but not as often as it would with the standard relay. I had ask that GM look into this a few weeks ago and would like to copy this as proof that someone else has experience the issue with the door being locked.
You are right the accidental press of the key fob with a 2 shot relay is very unlikely. I found my trunk opened twice outside before the 2 shot relay install and I believe my doors were locked.
When I purchase my 2012 the problem started 6 months after ownership both the 2 shot relay and a new key pad release were installed. I do not know if the problem persisted because I traded for the 2014 a few months afterwards.
About four months after I had the 2014 the trunk started opening so I had the 2 shot relay installed. Later the trunk key pad was replaced and several months later I found the trunk open. It has been a month now since the last time it was found open and if my theory is correct it will be a while before it happens again because a double signal is going to have to go out opposed to the standard signal.
The two shot relay solves the opening of the trunk from the accidental press of the key fob but there is another issue here.
 

FrogFan

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18
Ft. Worth, TX
Buick Ownership
2013 LaCrosse
Please feel free to use my experience in your discussions with GM. Let me know if I can be of further assistance.

I took delivery of my 2013 in December of 2012. My trunk started opening not too long after that, typically in my garage, but I did find it open in a parking lot at least once. I've replied to one or two threads here to document my experience, and it was in one of those threads that I learned of the two-shot relay. I had that installed at my dealer when I had the 7500 mile service done (I'm pretty sure of this, but I can check for sure if it's important). Since then, the trunk opening has happened twice, both times in my garage. I have my car set to lock automatically shortly after I exit the car, so unless the car somehow mysteriously unlocked itself, it was locked when the trunk opened.

Incidentally, I have not had the new trunk key pad installed. Moreover, my trunk key pad does not work very well. If I press it twice at the same speed I press my key fob, the trunk won't open until I press it at least a third, and sometimes a fourth, time. I'm not sure if that is related to the current problem, but I thought I'd mention it. It's such a minor annoyance that I haven't requested that it be fixed.

Good luck, and I'll be watching for further developments.
 

dbris

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163
5
18
Los Angeles
Buick Ownership
2011 Lacrosse CXS
Incidentally, I have not had the new trunk key pad installed. Moreover, my trunk key pad does not work very well. If I press it twice at the same speed I press my key fob, the trunk won't open until I press it at least a third, and sometimes a fourth, time. I'm not sure if that is related to the current problem, but I thought I'd mention it. It's such a minor annoyance that I haven't requested that it be fixed.

Good luck, and I'll be watching for further developments.
The new switch pad makes it work a lot better, but you will still have multiple presses. When the doors on my 2011 are unlocked, the trunk pad requires 2 presses but when it's locked it usually requires 4 or more presses. With the 2 shot relay, it's supposed to require 2 presses like on the remote.

Like you, I chose not to pursue it because it's a minor irritation and I don't think that they could fix it anyway, but the new switch is worth it.
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MHT

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Indiana
Please feel free to use my experience in your discussions with GM. Let me know if I can be of further assistance.

I took delivery of my 2013 in December of 2012. My trunk started opening not too long after that, typically in my garage, but I did find it open in a parking lot at least once. I've replied to one or two threads here to document my experience, and it was in one of those threads that I learned of the two-shot relay. I had that installed at my dealer when I had the 7500 mile service done (I'm pretty sure of this, but I can check for sure if it's important). Since then, the trunk opening has happened twice, both times in my garage. I have my car set to lock automatically shortly after I exit the car, so unless the car somehow mysteriously unlocked itself, it was locked when the trunk opened.

Incidentally, I have not had the new trunk key pad installed. Moreover, my trunk key pad does not work very well. If I press it twice at the same speed I press my key fob, the trunk won't open until I press it at least a third, and sometimes a fourth, time. I'm not sure if that is related to the current problem, but I thought I'd mention it. It's such a minor annoyance that I haven't requested that it be fixed.

Good luck, and I'll be watching for further developments.
I have forwarded the information to the GM Executive Office in hopes that this will help lead to a resolution to this issue.
I was the first to post the fix for the instrument cluster display default and the two shot relay for the trunk opening due to the accidental press of the key fob. I hope I will be able to report a fix for the trunk opening without any press of any button or key pad release.
 

MaryT

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NJ
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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.
 

CarbonBlackCXS

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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.
Perhaps water got into the switch when at the car wash and is causing it to short thus popping the trunk. You could check the condition of the rubber pad that you press to open the trunk. The high pressure may have pushed water past the rubber seal and into or on the switch.
 

MaryT

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NJ
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Perhaps water got into the switch when at the car wash and is causing it to short thus popping the trunk. You could check the condition of the rubber pad that you press to open the trunk. The high pressure may have pushed water past the rubber seal and into or on the switch.
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.
 
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