Anti-theft alarm goes off randomly

[JayMac]

Twice in the last 24 hours, my car alarm started going off when it was parked in the garage, with the car doors unlocked. It has an advanced keyless entry system, and the doors do not lock automatically unless I press the driver side door request switch, which I do not do when I park in the garage. But even if I had inadvertently locked the doors, I see no reason why the alarm would go off 12 hours later with the car sitting unattended in my own empty garage.

The car is a new 2015 CX-5 Touring, which I've only had for about two weeks. Not surprisingly, the dealer service rep had no answer as to what would cause such a thing. So far I have come up with one internet hit that speaks of a similar issue, possibly being the result of wire corrosion at the front right door pillar, which then triggers the alarm. But this cause seems unlikely to me being the car is only two weeks old.

Just thought I'd post this issue to see if anyone else had any familiarity with it.

 

[GP 2004]

How much did the alarm cost? I thought that my GT had an alarm, because the "!" button on the fob would flash the lights and sound the horn, but when I added a remote start I found out that it did not come with an alarm.

 

[JayMac]

Interesting question. All that shows up on the windshield sticker is "anti-theft engine immobilizer", listed under "standard equipment". The only "optional equipment" on the whole car is the crystal white pearl paint.

However, my understanding is that the engine immobilizer only immobilizes the engine from starting when it doesn't recognize the proper key, and that it does not sound off an alarm horn. The owners manual lists the "theft-deterrent system" as a device on "some" cars. I was thinking I have this because of the alarm horn going off, but the owners manual also says that if you have the "theft-deterrent system" there would be a sticker in the glove compartment indicating so. No such sticker was in my glove compartment.

So I may have to go back to the dealer and try to figure out what I actually have installed on this vehicle.

 

[thedaddyb]

Easy way to check is to roll down the driver window and then lock the doors. Give it about 30 seconds to a minute for the factory system to fully arm itself and then reach in and open the door. Make sure the key is not too close to the vehicle. The horn will sound if you have the factory "active" alarm.

They all come standard with the "passive" alarm which is the immobilizer chip integrated into the key.

 

[thedaddyb]

Easy way to check is to roll down the driver window and then lock the doors. Give it about 30 seconds to a minute for the factory system to fully arm itself and then reach in and open the door. Make sure the key is not too close to the vehicle. The horn will sound if you have the factory "active" alarm.

They all come standard with the "passive" alarm which is the immobilizer chip integrated into the key.

As for it to go off randomly without a real trigger, there might be something defective in the car. Either the alarm system or one of the door, hatch, or hood triggers is sending a false positive.