Trunk Lid Self Opening

[celltech]

Have a 2015 without the Ultimate package. When the car was young the trunk would go up by itself (at least when it was warm) after it was unlocked with the 3 second, stand behind the car, opening trick. The opening was never that strong and after time it just gave up and did nothing but unlatch. I let it go until recently when I took it in for a non-closing moonroof and added that to the list of things to fix.

The dealer tells me it's only only supposed to go up with the motorized package. Although the manual shows a happy guy with a heavy load of boxes standing behind the trunk, it never specifically states it's supposed to go up on its own. Seems like a useless feature unless it does, but I digress.

I got looking at a parts site to see how the mechanism works and in my non-motor version there is a coil spring (part 79231-B1000) at each hinge to provide the preload. But more curious is for the powered ones there are also gas struts (part 81771-B1010 ) like on a hatchback vehicle. I wonder if adding just 1 of the struts would open the trunk on its own? I am assuming the standoffs are already there to mount them.

Anyone thought of this before? I also am thinking of finding another spring to fit inside of the existing one to add a boost....I don't think it will take much to make it lift.

 

[pmcjr]

I'm having this same problem on my 2017 G80. When new, at least for the first two years, the trunk went up fairly easily when standing behind or when pushing the trunk release button inside the car. Then it began to slow down. Now I don't stand there and wait..I just push the trunk button above the license plate and raise it manually. This is the Base model, so I seriously doubt it's a motorized package. Never heard of that for this car. But the coil spring does make sense. Springs wear out. Thanks for bringing this up. I'll mention it at my next service appt.

 

[Suburbazine]

Hyundai just lost a class action regarding the Sonata smart trunks not opening as advertised. While the settlement only refers to the Sonata, I don't see how some arm twisting can't apply it to all Smart Trunk vehicles. Hyundai ought to replace the affected preload shock and spring as a courtesy feature.

 

[pulsar]

If you have an actual spring and not a pressurized strut, would not think the spring would really wear out? Struts leak from the seals after a while and get weak. A spring, unless over yielded or stretched to far should retain its base strength. I had a 30 year old Camaro with springs on the hood hinge and they always worked fine as long as I kept the hinge lubed some.

 

[Suburbazine]

If you have an actual spring and not a pressurized strut, would not think the spring would really wear out? Struts leak from the seals after a while and get weak. A spring, unless over yielded or stretched to far should retain its base strength. I had a 30 year old Camaro with springs on the hood hinge and they always worked fine as long as I kept the hinge lubed some.

Hyundai's problem is twofold. Poor torsion quality causing tension loss, and strut wear causing pressure loss. The struts have a nitrogen charge designed to pop the trunk the first few inches, then a limit valve to slow the trunk when it's nearing full open. The torsion bars are what provide the movement after the struts push past the first few degrees.

 

[surprisinguy]

yeah... mine worked "as advertised" for a few months then it's just a click and pop now - no go on the additional rise up.

 

[yolonge]

Anyone have the same issue addressed by dealer? One of mine brushed off in the past as well

 

[celltech]

I ordered one of the struts for $20 from ebay and will see if it "fixes" the issue.

 

[daviderle]

I had the problem when I got the 2015, got the dealer to fix it two months later, it has been wonderful ever since. I make sure I open the truck at least once a week. I found if I don’t it behind to slow down a bit after a while.
On the 16 the auto close button failed six months in.

 

[Fastbrick3]

I ordered one of the struts for $20 from ebay and will see if it "fixes" the issue.

Please keep us updated, would love to fix this issue on mine.

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[okcguy]

My 16 trunk won't go up on its own and it seems to have a couple of inches of travel to go at the top even after manually opening it. I'd be interested to see if this fixes the issue as well.

 

[celltech]

So not what I expected but it all worked out. Turns out my trunk already had 2 struts in there, even though the parts diagrams say it's for the power lift system. I ordered part 81771-B1010 while the car already part 81771-B1000 installed. I can't figure out what the difference is supposed to be. The old struts had no pressure and can be collapsed by hand while the new one is stiff as hell. Perhaps the old ones are just dampers and not for lift assist, as they do act more like a traditional shock absorber. They don't appear to be blown out as there is no oil leakage.

At any rate I pulled the left side off and replaced it with my ebay special. Bingo, the trunk opens like it's ready to consume my golf clubs. I actually would not want to be hovering over it when it cuts loose. But it does not open with a crash as the shock action slows it down right at the very end. I really don't think I need to replace the other one as it opens very strong right now.

All you need to pull off is the trunk liner on the top, then you can just fold over the side flaps to access the strut. I ended up breaking some of the plastic clip holders and had to hot glue them back together. Be sure to pull the weatherstrip gasket up and slide off the 3 metal clips first before attempting to pull the panel down. And don't forget to remove the 2 10mm bolts holding the shopping bag hook in place.

 

[surprisinguy]

Thanks for tackling this! I'll have to check it out soon. So do you think it's possible to remove the clips without breaking the "holders"?

 

[celltech]

I think that if you pull them straight out they could survive. That would take laying in the trunk and pulling as close to the clip as possible. You can their locations as the clip holders have rivets into the liner.

 

[TinsleyC]

To have the trunk open automatically by standing behind it, is that called Smart Trunk in the settings?

Mine was not working, then I found the Smart Trunk setting and it was turned off. I turned it on, but it still won't work.

I'm just supposed to stand behind the car with my key in pocket, right?

 

[Chad86tsi]

To have the trunk open automatically by standing behind it, is that called Smart Trunk in the settings?

Mine was not working, then I found the Smart Trunk setting and it was turned off. I turned it on, but it still won't work.

I'm just supposed to stand behind the car with my key in pocket, right?

Car has to be locked first, and with you not right next to it when it's locked. Scenario: you lock your car and go into a grocery store, you return 10 min later with full hands and stand by the back, it will beep 3 times to alert you it's about to open, then presto, it starts to open. It sometimes starts the 3 second count down if I walk past the trunk on my way to the driver side (while locked). If i keep walking to the drivers door, it senses I've moved past the trunk and stops the count down (and won't open accidentally).

Mine has always opened flawlessly, it gets used about once a week on average.

 

[Fastbrick3]

So not what I expected but it all worked out. Turns out my trunk already had 2 struts in there, even though the parts diagrams say it's for the power lift system. I ordered part 81771-B1010 while the car already part 81771-B1000 installed. I can't figure out what the difference is supposed to be. The old struts had no pressure and can be collapsed by hand while the new one is stiff as hell. Perhaps the old ones are just dampers and not for lift assist, as they do act more like a traditional shock absorber. They don't appear to be blown out as there is no oil leakage.

At any rate I pulled the left side off and replaced it with my ebay special. Bingo, the trunk opens like it's ready to consume my golf clubs. I actually would not want to be hovering over it when it cuts loose. But it does not open with a crash as the shock action slows it down right at the very end. I really don't think I need to replace the other one as it opens very strong right now.

All you need to pull off is the trunk liner on the top, then you can just fold over the side flaps to access the strut. I ended up breaking some of the plastic clip holders and had to hot glue them back together. Be sure to pull the weatherstrip gasket up and slide off the 3 metal clips first before attempting to pull the panel down. And don't forget to remove the 2 10mm bolts holding the shopping bag hook in place.

View attachment 25891View attachment 25892View attachment 25893

Awesome! Going to get mine ordered today.
Thank you

 

[TinsleyC]

Car has to be locked first, and with you not right next to it when it's locked.

That must have been it, it actually unlocked accidentally last night. The car is long, and I have to shimmy behind it in the 1.5 foot gap between car and garage door. When I did this, I heard the three loud beeps and the truck opened.

Not sure I'll keep it on, bit glad it works. I will rarely not have a hand free to open the truck.

 

[EdP]

That must have been it, it actually unlocked accidentally last night. The car is long, and I have to shimmy behind it in the 1.5 foot gap between car and garage door. When I did this, I heard the three loud beeps and the truck opened.

Not sure I'll keep it on, bit glad it works. I will rarely not have a hand free to open the truck.

I don't lock the car in the garage but once in a while it will be. I always back in the garage so when I leave the house by the door to the garage it would open the trunk. It is a nice feature once in a while but I rarely need it.

 

[Chad86tsi]

Not sure I'll keep it on, bit glad it works. I will rarely not have a hand free to open the truck.

I've had the car 9 months and I've only tried to use it once, and that time I had forgotten to lock the car so it wouldn't function. It's nice and I leave it on, but it's unlikely to get used much.