Hello All... 1999 Limited. Doors will unlock from both interior switches but will not lock. Any suggestions? Seen some posts from a while back but looking for more recent recommendations. Thanks much.

Door lock actuator?

Do the locks work both ways with the key switch? If they do then we can most likely rule out the ground circuit. We can check the circuit to the Body ECU, which is the most likely failure.

The locks do not work both ways from outside with the key. Only unlock also.

Silly question... Is there one door lock actuator or two? One driver, one passenger side? I'm getting the same "unlock only" behavior from each door.

I also have a similar issue, both ways. Mine will not respond if I press the unlock switch more than twice.

I picked up a spare under dash fuse panel/box thingamajigger (BCU?) that another member here suggested. But haven't tried it yet.

I also saw a mod where they change out the little motor within the actuator.

MSRP sticker said mine came with FOBs but not when I got it.

Not a silly question, but we do need to define "actuator". A door lock "actuator" is the mechanical solenoid which does the actual locking and unlocking of the door. Every door has a lock actuator, or as Toyota calls it, a door lock motor.

Now as far as what actually actuates the motors, it is done by the body ECU. There are many facets to this, but we can most likely trim it down to a few checks to find out if the Body ECU is defective or not.

The fact that both switches, and both door lock cylinders will unlock but not lock point to the Body ECU, but we should check some grounds, some connectors and such. Do you have an Electrical Wiring Diagram? If not, I'll have to get you the link, my main computer crashed so I don't have my old bookmarks.

Here's the info @DirtyDanno is asking for, though not necessarily what he needs.... do that figuring out first.

On mine it was intermittent and only the lft front and rt rear doors were affected- first it started with one, then the other. Using the key worked fine with the front door. The other two doors do what they're supposed to and always have. Sometimes the affected doors would partially lock, sometimes hitting the button a few times did it, sometimes they just twitched. When I took them out the actuators were 'working', just not doing the job. New ones solved the issue for me.
Anyway...

Post 1460- rear door, part number, where to find, how to at your own risk and discretion...
habanero's 1996 4Runner Build-Up Thread - Page 73 - YotaTech Forums
Posts 1463-1478
habanero's 1996 4Runner Build-Up Thread - Page 74 - YotaTech Forums

Post 901- pulling front door panel
habanero's 1996 4Runner Build-Up Thread - Page 46 - YotaTech Forums

My lock just started doing the same thing this morning. My alarm arms but won't lock the doors. It will unlock them though. The switches in the doors will unlock the doors but won't lock them.

I'm off to work, but clearly we need someone with the failure to take the time to do the diagnostic grunt work. I'll call in @TheDurk to supply the EWD that I no longer have. The easy knee jerk reaction is to blame the Body ECU, and with good reason, but I sure would like someone to actually check the grounds and switch circuits to be sure!

Had the same problem a couple years ago.

Relay integration box.....that's the part you guys need. There's a different split between the years than the body style split so I would get the part number from the dealer and then source it from another vehicle. Dealer price is 500 bones iirc. The relay integration is part of the internal fuse box drivers side under the steering wheel.

The reason for the all the other doors having identical problems is because all the other doors are wired under the driver side door and then the relay integration. So it's not actuators or anything else which is a good thing. Those parts can get expensive. I got my integration box for 20 bucks from a part out.

I'm happy to do so if I have them, but @baskelh does not provide his model year in his sig or ANYWHERE that I could see in his profile or build thread. It is a '99+ from the pic, but I'd rather not have to guess beyond that.

Just noticed. Have to change that in my sig. It's a 99 limited.

I have no clue whether this is good forum etiquette or not but just have to say you all rock. This is incredibly helpful and you all have my gratitude for chipping-in. I won't be able to follow-up on this for a day or two but this is a really great resource!

Here is a link to the '99 Door Lock EWD. Sorry for the upside-down pages. I'm going to work on that.

https://drive.google.com/file/d/0B1l...it?usp=sharing