Key fob sets off alarm when locking doors

Recently when trying to lock doors using the factory key fob, the alarm goes off. It happened enough that I stopped using keyless entry and went back to the key. Replaced the battery with the same results. Does it take a special battery? Does it need reprogrammed? FCC ID BAB237131-022.

 

My 06 has strayed doing something similar. It will trip the immobilizer when you unlock it with the fob. Changed the battery and it got better but the issue is still there.

Fob might be on the way out,

 

Figures. Always something!

 

Do you have an aftermarket remote start? With my remote start, if the doors are locked before I press the 'lock' button three times to start the truck it causes the alarm to sound.

 

No remote start. Just the 2 button fob with the little red LED at the top and the Toyota logo on the bottom.

 

It's happened to me on a few occasions, when it's happened I noticed the little red LED on the fob was lit up after I let go of the button. Seems it somehow got stuck and activated the panic mode. After smacking the fob around a bit the light went off and I was able to turn off the panic mode by pressing the button once again. My fob case was a bit worn so I got a replacement outer case and swapped in the old guts, working good so far.

 

I’ve noticed on my 2002 whenever this same condition has happened it was because my Engine Battery was near the end of life. Kind of like an early warning system letting you know its time to replace Engine Battery. I’m on my 5th Battery and its like clock work. Truck still starts and runs, but the Alarm activates for some reason when my Engine Battery is near EOL.

 

Reviving this thread because my issue is getting worse. What are the odds my key fob is messed up? I’ve got a relative new battery, I’m gonna get it tested just in case.

Anybody know how many anti-theft sensors an 06 double cab has and where they’re at?

ive seen mention of body control module tied into the alarms?

I traced the sensor on the firewall back into the cab to a shock sensor module

 

I was thinking, leave your door open, and fob lock it. Does it do the same thing? Maybe you have a door switch going south and the alarm thinks the door is open so it says hey hey hey hold on.

 

@FrenchToasty Man it’s intermittent as hell but I like where your going with the door sensor idea. It sounds a long solid beep when you try to key fob lock it with a door open.

I’ve tried everything I can to set the alarm off and can’t make it re-do it when I want it too. It just out of the blue will decide it doesn’t like to be unlocked with the key fob and flips shit. I stood in the driveway tonight locking a d unlocking with the fob for over 30 minutes and it never did it. The dang thing may go a couple weeks and never do it. I’m at a loss on it. I may try a new fob

 

Trying to understand....it's not the piezo(chirp sound) or the Theft Deterrent Horn switch inside hood handle assemb....it's the screeching sound when key is in ignition and door open ?

 

@BubbaW, so I’m chasing the anti theft alarm and Immobilizer randomly going off . As of right now my horns are disconnected. At least this way when It decides to flip out, I’m suffering in silence lol.

That response was for @FrenchToasty, I went back and edited it to clear things up a little bit. He was dropping some trouble shooting ideas for me to try. Trying to rule out door sensors but the double cabs won’t let you lock with the fob if a door is open

 

The 2 veh horns or the actual theft deterrent horn on drivers side frame under hood
by fuse blocks ?

 

Wait? There’s a 3rd horn? Right now I’ve got the vehicle horns disconnected. The 2 out front of the radiator are what I unplugged. Wasn’t aware of the one on the frame

So far I can’t find any common link triggering it.

I wonder if this thing is just triggering the immobilizer then? Man I was sure the security system was tripped but I didn’t unplug any other horns? Lights blink, horns blow, and truck refuses to even turn over. Go through a bunch of locking and unlocking sequences while pushing that security button on the dash and it eventually starts.

well im confused as hell now, I thought it was tripping the immobilizer but I don’t have a chipped key

will unplugging the horns disable the whole system? I tried the procedure in the owners manual to trigger it and can’t make the damn thing go off?

 

According to your 2005 FSM, the Theft Deterrent Horn(TDH) is located in same area my 04 DC Theft horn is located. I had an intermittent issue where the TDH would go off on it's own. It was an intermittent Theft Deterrent Hood Lock switch. While searching that issue, went down a rabbit hole searching more on Theft Deterrent but got more to discover when time permits.

DIY: 04 DC Limited Theft Deterrent System w/Remote Keyless Entry | Toyota Tundra Forum (tundras.com)

Will take a look at mine once I know it won't bother neighbors. As for checks you attempted from owners manual, it took me a bit to learn I wasn't waiting long enough for system to arm. My Theft Deterrent indicator light is on the right side of the Center Cluster, I rolled down pass window, armed system by locking doors with remote and light became solid, about 1 minute, the light starts blinking indicating system armed. I then reached in pass window and opened door....all hell broke loose. I did the same when checking hood switch....pop the hood release by driver footwell, lock doors with remote, wait for blinking theft light meaning it's armed, try to open hood and all hell should break loose.

 

@BubbaW, you the man. I’ll check it out after work today. I double checked my build sheet about the security system. It just list the
KE Remote Keyless Entry System.

I did hit my panic button on the way out this morning to see what happened. It triggered the blinking lights but didn’t get any horn action. Maybe somebody has already pulled that horn, idk what’s going on

 

When I got my truck last January, the remote was absolutely filthy. No pandemic hysteria, just felt it needed to be cleaned. I removed the screws that hold the circuit board on to the fob body and cleaned all the 20 years of who knows what out from around the rubber button. It felt like it wanted to stick every so often, but never set off the alarm. After cleaning it, it feels/works much smoother. I was surprised it worked at all to be honest...

 

@N84434 My remote could probably use a cleaning, appreciate the suggestion

So it appears I was somewhat right about having an oem system and not so right about that part. Toyota sold an upgraded kit for double cab owners. I think my truck had keyless entry only best I can tell from the build sheet and this “upgrade” system was added later. I’d bet money it’s causing my issue

stumbled across this thread that’s a how too for the install: