Power lock issues

Recently purchased my truck, 03 Tacoma double cab, and am having some issues with my locks. The door switches don’t work and neither does the key. If I manually lock the doors by pressing down the lock, as soon as I close the final door they all automatically unlock. Leads me to believe all my mechanisms are functional. Why does this happen? Truck has factory /dealer installed security system. I don’t have a fob. Any ideas? I have scoured the net and forum and can’t find an answers. One thought is does the door jam switch need to be functional for this all to work?

 

Likely security system, which is mainly driven off the fob. I’d try to find out what system you have and source a new fob. Then search for the programming functions to see if you can get it working correctly. Gulf states Toyota did a lot of system installs, which is what mine has.

 

Welcome to the forum!!

I am curious why this was not noticed in your prepurchase inspection??

First the doors unlocking is a safety system did you have a key in your ignition?? To prevent locking your keys in the truck.

If the Integration relay does not see that the door jam switches are open( doors closed) it thinks the doors are open and will not lock the doors.

The key in the Door lock cylinder should always unlock the door through the physical linkage. Just in case the battery is dead or disconnected .

The wire harness into the cab on the left door does break after 20 years. Switch contacts fail or just get dirty.

Add an Alarm into the system even more things can be wrong.

Time to break out the meter.

Happy hunting.

 

So I removed the factory anti theft system just to eliminate that as an issue. No change. I also fixed the to jam switches and tested them all. All are now good. No change. Some light will stay on even with doors closed. I have tested all fuses, ohm out just about every wire I could find. I changed out the door lock switch and no change. I am starting to think that possible the interior fuse panel circuit board is shot…?

 

Where did the Door switch come from and did you test both the old and replacement switch.

I don`t have the 2003 EWD so have you checked the voltage coming to the master switch ?

That would be a starting point if not an open circuit between the Master switch and integration relay or the relay is shot though yours might be called the Body ECU.

Good luck!