Anti-Theft System Constantly Going Off

I have a 2005 DC SR5 2 wheel drive with 120k miles. Recently, the anti-theft system has been going off every time I unlock the truck and open the door. I somehow get it to turn off by turning the ignition to the ON position and pressing the red button by my left knee on the lower trim panel. I have read this could somehow be caused by replacing the battery, which I have recently done. Can someone please provide me with some information on how to possibly reset the anti-theft control module, or any other advice? Thanks in advance.

 

See if the piddif here helps you out: https://www.tundras.com/threads/need-help-disabling-automatic-door-locks.33158/#post-1931311

 

Thanks for the reply; I had seen this one when I searched the forum, but I have a different problem. Any time I lock my truck...for any amount of time, and then unlock it, as soon as I open the door to get in the alarm goes off. Horns blazing, lights flashing, won't crank, etc. I am hoping to find some way to either reset the alarm, or completely disable it. Thanks again!

 

My 2006 was doing the same thing. It sounds like you have the dealer add on system. Do you have a horn on the drivers side fender near the battery?

I had a sensor going bad and mine would intermittently trip the security system when the keyless entry was used to unlock the doors. I had a local shop pull all that crap off mine. Majority of double cabs only came with keyless entry.

 

That is really interesting you mention the horn. Both of my horns are in front; however, one is near the battery, but not on the fender. Both in front of the radiator toward the center. The reason I say that is interesting is I have only owned the truck for a few months, but have had to replace the horns (both low and high tone) TWICE. Horn was blowing a fuse every time I tried to honk.....ended up taking it to the dealer and they diagnosed bad horns. I bought the truck from Lexus of New Orleans and they gave me brand new toyota horns when I bought it because it was a safety issue. What are the chances of both horns going bad......?

 

Alright so you’ve for sure got the port/dealer security system. Same setup I had.

It’s worth noting though when I disconnected my horns while trouble shooting the truck never tripped the security system again. Mine those was getting to the point where I couldn’t reset it with the red button on the dash.

I’m curious now, let’s try disconnecting your horns and see if it trips the security system when the keyless entry is used. It was probably a coincidence on mine but who knows lol

I stumbled across this while I was trouble shooting mine

 

@Snakeman can you confirm if your vehicle has one of those piece of shit KARR systems installed on it? Sometimes these got ported in for an exorbitant amount of money, the installs were hackish as hell, and caused a wild array of issues.

https://www.tundras.com/threads/what-is-it.47271/
https://www.tundras.com/threads/alarm-keys-transponder-etc-questions.80991/
https://www.tundras.com/threads/new-tundra-owner-unknown-switch.34928/
https://www.tundras.com/threads/2022-tundra.76839/page-548#post-2436247

 

PS - @Snakeman because I'm 90% positive you probably have the KARR system, especially if you live out west where they seem to be really prevalent dealer add-ons in all makes/models of cars, I'm going to drop the manual for the 4040a unit here which will help reverse the install.

Many users have found that simply unplugging the main brain, a black box with a footprint of two credit cards, side-by-side, fixes any nuisance behavior without killing your ability to start the car. You may also find a small blue KARR box which is the shock/vibration sensor used to sense impacts. Unplugging that module may actually fix your problem, when vibration sensors go bad, they'll trip the alarm brain regularly.