My trunk popped open for no reason at all on 3 different occasions. Twice when I went down to the garage it was open. (I keep the doors unlocked in the garage so I didn't hit the remote at all). And once we were in McD's and someone came in and asked if I owned the Hyundai and said my trunk was open. It was definitely closed when we went in there. What could be the problem?

Is the battery OK. low battery voltage will cause these types of things.

Is this an aftermarket key opener. ? The brain box for this unit is some times mounted behind the left kicker panel by the left foot of the driver. And they get wet from foot water ie snow. Rain. The yr of ur car sounds like this unit could be water damaged. Have a look. Is u see green stuff allover the contracts thats ur issue. As well some times older cars remote fob controller is not isolated from other sigs. Ur truck does it only pop open when parked in one location ie home or work u might be picking up a similar radio req as ur button for truck lid as they have different radio freqs to control different things

This is the key security system. Somehow youv'e set it off. Used the wrong key tried to open the door with the alarm on. Opened the door or trunk from the inside after locking it from the outside. If your the real owner of the car it'll be no problem to get it fixed. If you have the correct key lock the doors from the outside with the key and lock it twice ( the doors ( all of them ) should lock). Leave the car alone for a minute, maybe 5. Then unlock the door twice, all the doors should unlock the second time. Enter the car and start it with the key. If you with a remote door lock fob that can work too. If this fails then try a different door or even the trunk. Sometimes the driver doorlock switch wears out or gets ice in it and unlocking a different door or useing the remote can get you going again.

You might just need to reset it. Roll the drivers window down and close all the doors. Lock all the doors with the key ) turn the key to lock twice, The electric locks should lock all the doors. wail a few minutes and unlock and open the trunk with the key. relock the truck or just close it. unlock the drivers door with the key, twice. all the doors should unlock, get in and start the car. Now this does'nt always work. If it does'nt we'll make the system think it's running. Close and lock all the doors. open the hood and disconnect the battery, one ccable will be fine. wait a few minutes. Reach in though the open window and turn the key all the way on. Don't open the doors, go around and connect the battery hard so it does'nt jump or skip. Reach thought the window and start the car/ once it's running. turn it off remove the key and unlock the door from the inside and open the door ( as if you were inside.) get in and start the car and everything should be back to normal.

Unlock the drivers door with the key

open trunk, disconnect rear trunk light. use jump box and connect wires to pos neg on jump box. this will give u enough juice to open doors, I have done it twice. easy to do

Simply hold down the button you want to use (there are 3 for up to 3 different garage doors) until the light flashes and keep holding it down. Now place the garage door opener up near the sun visor and hold it's button down until the light on the on button you are programming flashes. It is now programed. The other 2 are done the same way. Good luck. It took me a while to find the info, it's not in any Volvo manuals I could find.

Mike

a garage door opener in your area is most likely doing this. back you car down the drive and park close to the house or wall.

jimmy: it sounds like the drivers door unlock tamper switch or the other switch may have failed. One side can affect the other under certain circumstances. Your trunk lock also has a switch which arms and disarms the antitheft system. Try locking all the doors, make sure the hood and trunk lid are closed and then open the trunk. Leave it open open the drivers door and try to start the car.
If it's a no start. Disconnect the ground battery cable then put the ignition key in the run position in you ignition switch. Reconnect the battery and try to start the car. It should start. This usually will override the anti theft system. One issue with this will be, whether the antitheft system will remain disarmed.
Although I have never tried this before, I know that the system will not arm unless all the doors, trunk and the hood are closed.
I could suggest this to try if the car starts as I had told you pertaining to disconnecting the battery cable, I would take the switch and unbolt it from the passenger's side of the engine compartment just forward of the shock tower. Just let it sit somewhere so it doesn't get caught up in anything moving. If there is a light under the hood of your car, remove the bulb.
Let me know how you make out.

take the remote apart and take the battery and get it matched and replace it you can do this at walmart or a battery store.. youalso need to check the fuses because if the trunkdoesnt open and the fuel door does . there on the same fuse and it could be a more serious problem .. try cleaning out the lock cylinder on the trunk it is exposed so it will get dust and dirt and water in it..