Hi I have a 2016 is200t. I recently purchased the car at 23000 miles. The alarm system has been randomly going off with about 5-7 beeps. I'm not sure if this is something to do with the battery maybe or a bad sensor for one of the doors maybe. Just curious if anyone else has had this problem or knows of any solutions. Thanks for the help guys

 

Welcome to the forum.

When you mentioned the beeping, are you referring to the Horn or the Chime that sounds when you Lock/Unlock your doors? If it's the Horn then it's likely the anti-theft system...if it's the Chime then it's something else.

 

It is the horn going off. I heard it go off a few times again last night and this morning and its definitely making 7 beeps when it goes off.

 

I guess the first obvious answer is that someone is messing with your car. Assuming you have ruled that out, then this leaves you an issue with the hood, doors, or trunk.
When the alarm activates, the Horn should sound approx. every half second for 57 seconds...unless something stops it.
So if you let it go on its own, you should hear the Horn go off about 114 times...which doesn't sound like the case here.
The alarm will stop when either a key is brought near the vehicle (within 1 metre of a detection switch, so either front door or trunk), you press the button on the remote, or the doors are locked.
I'm not sure how it's stopping at this point, unless it's doing it on it's own.
Also, you should see the interior lights on and all exterior lights flashing while the Horn is sounding. Your car should look like the the fourth of July.

If the car is stock with no aftermarket accessories, given the age of the vehicle (5 years) and the climate you live in (Arizona), if you have the original battery, then I would suspect that the battery is nearing the end of it's life.
Sudden voltage fluctuations could also trigger the alarm system.
Outside of that, trying to figure out which switch in the hood, doors, or trunk is setting it off is literally almost impossible.

My suggested steps:
1. Check the vehicle for any aftermarket electrical accessories
2. Have the battery tested to see what it looks like
3. Pray to whatever God you believe in

 

So I got my battery checked yesterday and I have a perfectly fine battery. Not sure what might be causing this it must be a bad sensor on a door or trunk or something. Im taking it into the dealer on Friday for service and am going to ask them to check it out.

 

Good news that the battery is ok, but bad news that there's still no solution yet.
Can you tell if it's the original battery? Some times when a cell is intermittently shorting in a battery it will test perfectly fine when the cell isn't having an issue, so unless you can test the battery when it's actually malfunctioning, it will always seem like the battery is fine.

You mentioned it beeps about 7 times...what stops it from beeping for the full 57 seconds? Are you pressing the remote button or going out to the car with the key?

 

when you say beep you mean the horn or the light chirping beep like when you lock it? I assume the latter, that's what it does if you leave the car running with the key with you, or I think if you leave something open. Also curious if you watch the dash while its beeping for warning notices.

 

He already mentioned it’s the horn.

 

It beeps 7 times and then stops by itself. I even had it do it the other day when I locked my car and started walking inside it beeped 7 times. It does it when the key is near the vehicle or even if my keys are sitting in the house.

 

A couple reasons makes me believe this is not the alarm system activating:

1. The alarm is supposed to sound for 57 seconds unless stopped...consistent 7 beeps and stopping by itself does not align to this operating parameter
2. You mentioned it goes off with the key near the car...this is not possible...once you are close enough for the car to detect the key, then the assumption is that the vehicle is not being stolen

Did you happen to see if the vehicle has any aftermarket accessories installed? That's the first thing the dealer will ask you and that they will check for
Can you record a video of it happening and post it? That's the second thing the dealer will suggest, as they will likely not find anything wrong with the vehicle unless it's actually doing it

 

Its been months and I still am having this problem at random times. I am going to take it to the dealership soon to see but i have no clue what could be causing it and I have found nobody else with the same issue. I finally got a video of my car doing it. In the video it happens 2 times back to back.

 

I watched the video, then I went to my 2014 IS250 and set off the OEM theft deterrent system.
Unless your 2016 IS200t has a completely different theft deterrent system, that is definitely not the OEM theft deterrent horn pattern.
The pattern your have is 7 quick beeps of the horn, then a pause, then another 7 beeps.
The pattern I have is a steady blow of the horn probably every 0.5 seconds non stop...doesn't stop after 7 beeps, doesn't stop after 14 beeps.
Never mind all the lights are flashing on my car too...which I didn't notice the lights on your car going off at all...of course the video angle wasn't the best to see the lights, and it was daylight out, but I'm pretty sure the lights were not flashing.

Are you sure there is no aftermarket alarm system or remote starter on the car?
I would show the dealer the video, but they are going to tell you that is not the OEM Theft Deterrent system going off.

 

Did you ever diagnosis this? Mine does the same thing and it's driving me crazy.

 

Hi I'm having the same issue and found out that its the anti-theft alarm system. Its so sensitive to the point that sometimes it makes me wonder how it is being triggered. The horn will do a fast short 7 "beep". It can happen randomly sometimes but it normally happens when you get close to the vehicle when your key fob is with you. I tried troubleshooting by pressing the button of the alarm then the symptoms stops from occurring. Eventually after a month, I notice it starts to do horn beeps again.

I think its normal, and its part of the anti theft alarm. Its just that it is programmed to be too sensitive to changes in the car and its surroundings.

 

When I read the OP, my immediate thought was the car battery.