Alarm sound for no reason

[Voytek]

Hi, our Interstate was parked on our driveway with locked doors. Without any reason alarm start sounding with flashing lights. we stopped it with key fob. I noticed that when I shot close driver door or sliding door alarm sound once.
Does anyone have any idea what is going on there?

[Alex AVI]

VOYTEK - I have 2018 AI built on a 2017 Sprinter and pretty sure I dont have the ATA option. I dont get any audio confirmation when locking like you do. Maybe you got aftermarket installed by dealer? Or the Sprinter they used came with the ATA option? My understanding is the ATA and security options include tow alarm and motion sensors. If that what you have, then it triggered one of those

[Voytek]

Thanks Alex Avi,
I do not think we have a security aftermarket alarm system. We bought it used... It happens today during hot day, if was loud continuous horn like sound for about 5 min then sounded off. Car was locked and during siren I did unlocked it with fob open the doors everything inside was ok, loud horn sound was coming from around rear passenger side wheel base. No idea wat was causing it... Could it be faulty propane alarm? But no LP smell... I called Airstream dealer and they said it is probably MB problem and I should call MB dealer.

[Alex AVI]

Originally Posted by Voytek

Thanks Alex Avi,
I do not think we have a security aftermarket alarm system. We bought it used... It happens today during hot day, if was loud continuous horn like sound for about 5 min then sounded off. Car was locked and during siren I did unlocked it with fob open the doors everything inside was ok, loud horn sound was coming from around rear passenger side wheel base. No idea wat was causing it... Could it be faulty propane alarm? But no LP smell... I called Airstream dealer and they said it is probably MB problem and I should call MB dealer.

VOYTEK - OK, horn vs. siren sound - that matters because if it was horn sounding, then maybe it was the propane alarm. I don't think the MB ATA (even if yours came with it) utilizes a siren. Manual states horn sounding during activation. But when I accidentally trigger my interior propane alarm (which is on that rear pass side), it was a pulsing beep, not continuous. I have not read anything pointing to an exterior propane alarm. I have never heard my propane alarm from outside, so no idea how loud it is. You can trigger the propane alarm intentionally by blocking the inside sensor and maybe that will confirm if the sound is the same in pitch/volume. Also, AFAIK the propane alarm is not reset-able by the keyfob. Grasping at straws here - the subwoofer/amp is on that same side. I dont think that a subw is capable of that high a frequency, but a malfunction can still cause some audio??? This is indeed weird situation you are into.

[Voytek]

Thanks for the input.
I was looking in the MB manual. It says that there is a ATA alarm and it is set when you lock the car with the fob. Also I did see on internet articles about the bad batteries in siren device which is installed in wheel well. I guess I will need MB dealer to look in to.