Welcome to the Cadillac V-Series Forums!

Alarm goes off for no reason.

FLYARMY

Seasoned Member
Joined
Apr 21, 2022
Messages
855
Location
Montauk Point, Long Island, NY
V-Series Cadillac(s)?
2022 CT5-V Blackwing
Its 12:58 am and my 5BW alarm suddenly goes off. I jumped out of bed and look down on the car from my bedroom window. I go and check my security cameras and the car alarm is activated for no reason whatsoever. Anyone else have this happen to them ?
 
Glad I’m not the only one.

It’s happened to my car now 4 times in the last two months. Twice while in the locked garage.

The message I am getting is ‘door/trunk/gate open’ even thought the car is locked and everything is closed.

Coincidentally this only happened after my subscription to OnStar renewed.
 
This is probably not it, but just food for thought and/or an amusing anecdote. I guess it depends on how easily amused you are. ;)

So, a long time ago as a wee tot, I had a BMW E38 7 series, which was IIRC the first car that I ever owned with a factory alarm system. It was parked, locked, in my carport. Every-so-often, the alarm would go off. I'd run outside to confront the thief, but no one was ever there. No kids, pets, etc. either. It became fairly frequent.

Then I found a pattern. It only happened when I was making a snack, and often briefly microwaving a small item (like softening a small pat of butter). Further testing showed that it was leakage from the microwave, apparently on the same frequency as the "panic" button on the remote. A new microwave oven fixed the BMW.

So, if it happens to you guys on a pattern, it could be something else (including a neighbor) that is sending out a signal.

I also had this happen to a Porsche 911 I once owned, it thought the radio was being stolen and would set off the alarm. I solved that one by selling the car. :boogie Stupid German electronics.
 
20240621_081359.jpg


I have sat in the car with this and it doesn't recognize the key. Figure every little thing helps.
 
I do, and even bring it with me when traveling.

With regard to traveling... Toyota does something that I wish other manufacturers would do. They have a simple button press sequence (press and hold Lock, then press Unlock twice while Lock still held, look for fob to flash four times) that disables the key, no need for Faraday pouch. Wish others would figure this out. (If they have, I haven't noticed.)
 
With regard to traveling... Toyota does something that I wish other manufacturers would do. They have a simple button press sequence (press and hold Lock, then press Unlock twice while Lock still held, look for fob to flash four times) that disables the key, no need for Faraday pouch. Wish others would figure this out. (If they have, I haven't noticed.)
That sounds like it only disables "your own" key fob. Thieves are scanning the frequency spectrum until the signal is found.
 
Glad I’m not the only one.

It’s happened to my car now 4 times in the last two months. Twice while in the locked garage.

The message I am getting is ‘door/trunk/gate open’ even thought the car is locked and everything is closed.

Coincidentally this only happened after my subscription to OnStar renewed.
Today I saw the same notification on my phone app. When the alarm went off, I was about to run out of the house in my underwear with my Sig 9mm ! I hope this does not become a common occurrence.
 
That sounds like it only disables "your own" key fob. Thieves are scanning the frequency spectrum until the signal is found.
Yes, and? Similarly, a Faraday pouch only "disables" the key that's in it. I'm not following your comment. What other key fob would you want to disable?
 
Today I saw the same notification on my phone app. When the alarm went off, I was about to run out of the house in my underwear with my Sig 9mm ! I hope this does not become a common occurrence.
You can switch it up so it doesn’t get boring. One day the Sig, the next the 12ga, 300BLK SBR, MP5, etc.
 
I keep my key and the spare (wife's) in their own faraday pouches. As I understand it, a relay attack has to find one of the keys otherwise it is not going to work.
 
Yes, and? Similarly, a Faraday pouch only "disables" the key that's in it. I'm not following your comment. What other key fob would you want to disable?
The point I was getting at....is they don't even need your key fob to steal your car. They are able to scan the spectrum and start your car and drive away with your key fob on the kitchen table.
 
I may have found one reason why the alarm went off. I left my driver and pax windows down about 3 inches, last night. I don't know if it triggered some interior sensor.
 
The point I was getting at....is they don't even need your key fob to steal your car. They are able to scan the spectrum and start your car and drive away with your key fob on the kitchen table.
Pretty sure they need to read your fob, first. That's why the criminals come near to your door (to find the signal from the key).
 
The point I was getting at....is they don't even need your key fob to steal your car. They are able to scan the spectrum and start your car and drive away with your key fob on the kitchen table.

If that's the case then I give up. But that's not my understanding (I could very well be wrong).
 
IMHO, it's a relay attack. That's why they have such large antenna's and get close to the front room/kitchen/garage where the key fob might be sitting.

They can also directly attack the CANbus in modern cars... the more computers there are...


 

Win 2 Supercharged Cadillacs!

Win both supercharged Cadillac Vs!

Supporting Vendors

Exhibitions of Speed

Signature Wheels

Taput Tunning LLC

V-Series Marketplace

Advertise with the Cadillac V-Net!

Torque Shop

Our Partners

Back
Top Bottom