Thread: Alarm system keep going off intermittently

... throughout the day and NIGHT. I’m taking the car to the dealer today and hope they can find out what’s going on because this is frustrating.

Anyone else come across this issue?

I am actually on vacation the past two weeks and got a call from my neighbor telling me my Venza's alarm has been going off a few times the past couple weeks, they checked it out and nothing they can tell is causing it, I guess Ill find out when I get back home next week.

I'm new to the forum and have a similar issue. have an '09 4cyl AWD bought used and have had the alarm go off intermittantly on several occasions (horn blasts that last about 5 min or so, then goes off and on about every 1/2 hour or so). there is nothing "obvious" causing this to happen and leads me to believe that the system is too sensitive. I'm bringing to the dealer next week to investiagte and will let you know what they discover...although I'm not confident they will figure it out either.

WOW - I am glad to learn that other Venza's alarms are "sounding off" too. My Venza "sounded off" 7 times in the middle of the night (3:00am - 6:30am). It happened with and without the doors being locked, no one or anything by the car. I was so embarrassed and so tired!

First it happened a couple of months ago, took it to the dealer and they said that they could not replicate it - and sent it home without doing anything. And It went off twice during Sunday School. So everyone at church knows the sound of my Venza. I took it back to the dealer and insisted that they fix it because something was malfunctioning whether they could "replicate" it or not. I will find out tomorrow what (if anything) they did to fix it.

the other day my keys were all smooshy in my pocket with other crap and i accidentally held the horn button down somehow while sitting.

sat there cursing the idiot that parked in the complex and let their car alarm go off for 10 minutes.

before i realized it was my car.

Has anyone who took their's to a dealer for this issue had any resolution? my '09 V6 AWD has been doing this periodically for a few months now - every few weeks or so the alarm will start going off without reason, intermittently for a few hours, then be OK for several weeks.

Does the car record an error code when this happens?

I'm having this issue as well (2009 V6 AWD). I'm about to take it to the dealer as it is getting worse. I've heard that there might be a pressure sensor that is tripped when there are substantial temperature changes when the car is locked up tight. Has anyone else heard this. Also, I'm reading here and in other forums that there IS a sensitivity switch and other posts say there is NOT. Which is it? Can anything be done?

TSB-0208-10 resolves this issue. this TSB has been posted.

Is that the TSB for the same issue in Highlanders?
Post a link please - I looked for it without success last summer.

My dealer replaced the alarm switch located under the hood (which I believe is the Highlander issue). Then the alarm would sound if the door was left open more than 30 seconds or so. That was the dealer's fault: factory configures two settings for the alarm, one that arms it when doors are left open and one that only arms it when all doors are closed and locked. They left it in the former mode after resetting at the visit to replace the hood switch. No reference to the "armed when doors left open" mode in the manual, and only one tech at the dealer knew about it when I brought back again.

That was last fall and it's been fine since.

jdc: never heard of the alarm switch being activated by changes to interior pressure - it has been mentioned that the hood switch is susceptible to moisture penetration that causes it to short under varying weather conditions.

I just checked - the TSB is related to only the Venza. However, I have read other forums where this is a known issue with some highlanders.