That sounds right. If you use a screw driver in place of the door striker and close the latch yourself does it open from the handle inside and outside each time correctly and lock and unlock correctly?
Checking it that way, I noticed that when I pull the inside handle and then use the screw driver to engage the locking mechanism, the mechanism doesn't work. It moves freely but doesn't engage, so fully opens again. The inside lock/unlock switch is at this point stiff and doesn't move much.
As soon as I lift the handle on the outside of the door, there is a noticeable clicking sound and everything is back to normal. The lock mechanism gets engaged with the screw driver and the lock/unlock switch can move again.
Also, going back to the start, if after I pull the inside handle I can get the lock/unlock switch back into the lock position, then the door mechanism does engage (the above happens when its in the unlock position).
use the screw driver to fully latch the door latch, then open the inside handle. It should release itself. Latch it, then use the outside hand, should release. Latch it then lock the door, then try both handles, nothing should release. Unlock it and try the inside, then lock/unlock and try the outside. Try it all the ways till you find what sequence causes the problem. Possible you have a bad door latch, but need to confirm.
So I went through that sequence of locking and testing the inside and outside handles and it boils down to when the inside handle is pulled, irregardless of whether the door is locked or unlocked or the door latch is activated or not, the door latch malfunctions. This then gets reset once the outside door handle is pulled.
When the door has the switch in the locked position and the inside handle is pulled, as expected the door latch doesn't disengage but the second symptom appears - the door lock/unlock switch stiffens up and no longer works (this happens each time the inside door handle is pulled). The switch returns to normal after the outside door handle is pulled.
When the door has the switch in the unlocked position and the inside handle is pulled, the door latch does disengage but cannot be reengaged with the screw driver. And as above the lock/unlock switch looses its ability to move. As soon as the outside door handle is pulled, the whole system is reset and works as it is supposed to (until the next time the inside door handle is used).
Is there something that would cause this behavior that I can fix rather than shelling out for a full lock assembly?
I'm not sure, all the switches for door lock are inside the door lock actuator. But it sounds like this is a problem with the latch itself and not the lock actuator. Maybe. If you take the lock actuator out of the latch and function it (obviously make sure it's in unlock position) does it behave normally as far as latching and resetting itself to latch again?
So I took the door actuator off and reassembled the rest of the lock assembly and the same issue, with the latch malfunctioning when the inside door handle is pulled, occurs. So it looks like I do have a fault in the latch itself.
Has anyone ever tried to repair the latch mechanism itself? Are they repairable?
The broader question, for everyone else, is does that mean the door actuator I got on eBay for $17 does actually work in the Celicas? I guess someone else will have to try, since I disassembled mine one.
I dunno. You seem pretty legit, I can just send it if you pay shipping and if it turns out it's not the latch just send it back to me. If it does fix it then pay me $35? I'm keeping the DLA to rebuild to sell or for a spare.
Thank you TRD01GT for your excellent post showing how to remove and rebuild or replace the motor. I am working on a 2001 Celica GTS which has a defective driver's side door lock, and reading your post and viewing your photos has been invaluable. Thanks also to all the others who have contributed to this.
My front RH door actuator will unlock every time, but will only lock about half way. You can give the manual knob a little push and it locks. I took the latch unit off the car and it doesn't seem too hard to cycle the lock/ unlock. There is a spring in the mechanism that seems to be functioning correctly, but maybe not?
I split open the electric actuator and cleaned the motor brushes. I'm trying to figure out how it works to lock. The lever arm is forced up by the cam, but I don't see where there is anything to force the lever to return down when the cam is reversed.
Also, whats up with the online aftermarket parts? None of the replacement latch assy pictures they show look like what is on my car.