Misbehaving doors locks and questions about techstream

Hello all,

I've run into a bit of an issue with my 2014 tacoma and I'd like to see if the community has an advice or answers.

About a year ago I noticed my door locks would try to unlock twice when I opened my front passenger door (double cab). Decided to do some testing and here's what I've found:

-It only happens with the front passenger door. The rear doors do not cause the locks to act up.

-it only happens with the keys in the ignition. Doesnt matter which part of the switch the key is turned to. Itll do it. With the key out it doesn't happen.

-I don't think the key fobs have anything to do with it. With the key in the ignition the truck doesn't respond to the fobs (oem fobs. not aftermarket fobs or aftermarket system)

-If I open the door and press the plunger the dome light will turn off and door ajar light in the dash also turns off. When I release the plunger the locks will try to unlock again.

-With both interior door lock switches unplugged the truck will still try to unlock

- I've owned this truck almost 6 years (2nd owner). Never had any electrical work done. Havent had water in the cab. Only thing I've noticed throughout the years is this specific door seems to be a bit stubborn to close from time to time.

So I guess my question is, will techstream show position or status of the door latches? My only theory is the door latch still shows its locked and the truck is trying to make it unlock. Kind of at a loss and don't have direct access to techstream at the moment unfortunately.

 

There is no scan tool access to the Body ECU on 2nd gens via Techstream or any other scan tool.

That being said are you positive there's not an aftermarket alarm wired in under the dash somewhere?

 

I can take another look tomorrow morning. But im 95% sure there isn't an aftermarket system on the truck unless they've hid it super well and it uses all the factory lights and horns.

 

I would for sure want to rule that out first, beyond that it's gona be checking voltages at the Body ECU which is kind of a pain due to it's location.

 

Just took a quick peak under the dash and pulled some plastics down a bit. I can follow the harness clump from the back of the switch and I dont any interruptions in the harness

 

I can see a harness through the steering column adjustment lever and it looks fine. I saw another that might been the ignition switch or the wiper stalk. Both look clean from where I can find them to the fuse box

 

So the locks cycle when the passenger door is opened or when the passenger lock button is pressed?

 

Im going to bet a tucked away "deactivated" dealer installed alarm as mine on my truck *knocks on wood* has been trouble free but does do different things than normal vs stock (IE, locks all doors if all doors are shut and truck is keyed on, unlocks all doors when truck is keyed off afte running).

Or some VERY random shorting where the wiring harness bends at the door hinge.

 

Only when the door is opened and then closed

 

Guess ill spend some time this weekend and actually pull all the covers down. Mine doesn't do any of that kinda stuff. But idk what else it could be.

I'll also look over the door harness again.I looked it over way at the beginning and didn't see anything. I just ruled it out since I can make it act up without moving the door and just pressing the door ajar plunger

 

Plastics came down this morning and unfortunately I'm not seeing any signs of an anyone being in here after if was assembled.
Unless its shoved way up behind the instrument cluster in an area I can't see very well. Did take a peak behind the cover for the door harness going to that door and didn't see anything out of place. I have the harness a pretty good pull and stretch around the entire range of motion and that changed nothing.