Car locks and unlocks itself

[scott1686]

On Sunday, for some reason my car kept locking and unlocking itself while it was sitting in my garage. At first it was only once every few minutes, so I basically ignored it. Later on though, it was happening every few seconds, and it was double-locking itself fast enough to cause the horn to beep. And of course by the time Game of Thrones was on, it was beeping literally every 5 seconds at some times, and then it would stop for a few minutes before picking up again. I tried plugging / unplugging the charging cable and that didn't affect anything, and I also tried taking the battery out of the fob and that also didn't change anything.

Yesterday (Monday) morning I took it into the dealer, and they kept it overnight because they said they couldn't figure it out. This morning I got a call from them basically saying that this was expected behavior and they assumed it was the theft alarm caused by unplugging the car when it's locked (I've experienced that before and this definitely was not that). I then had to explain the issue again and now they're doing more research.

Has anyone experienced this issue? If so, what was the solution?

EDIT: I forgot to mention that Monday morning when I dropped it off the issue wasn't happening anymore.

 

[JMenacker]

Happens to me sometimes when fob is in pocket and I am crouching down - pants press on fob button causing unexpected locking/unlocking of car. This happened last weekend when putting summer wheels/tires on the car and resetting TPMS.

That doesn't seem to be your case though unless you were doing squats the whole time with fob in pocket? It may be worthwhile to check voltage of the 12v battery. Perhaps low voltage can cause unexpected module behavior?

Joe M in WV

 

[scott1686]

I just heard from the dealer again and they said the only error code the car had was a low voltage reading for a fob, so it's possible that my backup fob that I never use was acting messed up. I'll replace the batteries in both fobs and then post an update if it fixes the issue in case someone else runs into this.

EDIT: As soon as I got the car back home, it started doing the locking again. I took the battery out of the backup fob that I never use and then the beeping stopped, so that was the issue.

 

[SparkE]

I recommend keeping the fobs as far away from the car as possible, to (1) not needlessly drain the batteries, (2) avoid weird behavior.

I actually have a small metal tin that I drop the fob into when I get home to block all 'radio' signals (the backup is 60-80 feet away in the master bedroom).

And (not for the Spark) *any* car you have that has the functionality of "you touch the handle with the fob in your pocket and it unlocks" - you should keep your fob(s) in metal containers (faraday cages) and/or far from the car when at home. There is a class of car thieves with "signal boosters" that allow them to 'boost' the fob signal and get access to your car.

 

[Kermit]

Not all metal tins work. We had a tin and put the keys in it with the key near the car and it still unlocked the door, we tried aluminum foil over them and that also did not work. We got some cheap pouches from Amazon and we slip our cars in them and they work great even with the fob right next to the handle the cars will not unlock (this is with our Gen 2 Volt.) "MONOJOY 2 X Car Key Signal Blocker Case" is what they were called when we purchased them. There have been reports around our town that people have had their cars broken into and the doors were still locked which is because of these signal boosters.