Prius alarm will NOT stop!

Have you taken batteries out of both fobs and replaced them with new batteries? Rechecked and cleaned the battery connections by brushing them with a wire brush and tightness?

 

Has the alarm gone off unprovoked in any other location besides being parked at home?
Or maybe more simply does this happen everywhere?

Surprised the dealership had no suggestions. Even if that suggestion turned out to be, the whole system is shot.

Sorry I can't be of more help. Good Luck tracking down and solving the problem

 

I had a VW Rabbit with annoying electrical problems. Took a year to chase down the random starting problem. Turned out to be a burnt fusible link along the side of the hood. You know, a 99 cent fix. Check and clean all your fuses?

 

welcome! which battery was replaced, hybrid or 12 volt?

 

lock and unlock the drivers door with the metal key a few times, it might reset the system.(worked on an old ford I had)..might try cycling the car on and off a few times with the fob in the dash...

 

And have you checked the state of health of the 12 V battery as well as the connections of the negative to the car body? All clean and tight?

 

Has a phone company installed a new cell tower, upgraded an existing cell tower to 4G or increased the power output of an existing cell tower nearby where you live three months ago?

 

Well that's why I asked.
And that's huge.

Obviously something in your area is now intermittently triggering your alarm.
I suppose it could be a cell tower or who knows?
I wonder if your system could be reprogrammed to accept a different frequency or code?

Curious however, because I can't really remember reading a thread where somebody had a "rogue" signal triggering their alarm system. BUT that does seem to be what is happening in your case.

I'd call the dealership and present this specific theory. See if they have any ideas as to how to possibly counter this reality.

 

When you called the dealership did you tell them you thought that perhaps a rogue signal from an outside source was setting off your alarm?

Because if not, then hooking it up to the dealership diagnostic tools is just going to reveal that the system is actually working. There's nothing wrong with it, it's just picking up a signal from around your home.

To be honest if that's the case I'm not sure what could be done. But as you say there are other Prius around and they aren't manifesting the same symptoms. Which would lead me to believe perhaps a code or frequency change might fix the problem. I know from threads where people have lost their fobs and replaced with new, that the system can be reprogrammed to accept a new signal. I don't know if the system can be reprogrammed to accept a new signal from an old or original fob.

Good Luck.

 

I found this on disabling the alarm system

Thank you for your patience and waiting. I think we can do this one of two ways. One is through the Dealer and involves using the Techstream scantool. There are several features that can be customized to prevent the noise aspect. One will deactivate the horn from being sounded to warn that the car is being broken into. The lights will still flash but no horn.



The second method involves disconnecting the hood pin switch. It is connected to the hood latch and is a 2 pin (wire) connector that when disconnected lets the body computer 'think' that the hood is open thus the alarm will not activate in preparation for security. You will have to remove the plastic cover and access the hood latch and disconnect it.

if this only happens where you live then its either cats jumping on the car or someone has the other fob pressing the panic button to screw with you.......or you live on radioactive waste..... good luck

 

I had this problem too. What I ended up doing was to replace the micro switches on the key fob circuit board. First it was the alarm button, then the lock button, and finally the unlock button. They just failed over time. I felt comfortable enough to desolder/solder new button switch. That fixed the problem.

 

Yeah, your FOB's may be worn. What's odd though is you said you took the batteries out, and it still went off. Well, hop you got that resolved. Good luck.

 

Hey I saw that you commented regarding this issue is a few posts. I am trying to jump start my 2007 prius and the alarm goes off when the car starts. Do you have any suggestion to deactivate the alarm or get my car to start?

 

i would start by fully charging the battery, or replacing it