I wanted to follow up to let everyone know the outcome of my investigation into my door lock not working. To be a bit more clear, it was both my driver's door and my rear cargo door that were intermittently not working. The cargo door was a serious problem because there is no key hole or interior knob to manually lock it so with the door lock not working it was left unsecured.
I was able to fix the door locks in my 2007 (4.3) but I am fairly certain this information will apply to the 4.2 generation as well which seem to have this problem much more frequently than the 4.3s. I ran into a number of threads where the locks stopped working on the 4.2 generation vehicles but I couldn't find any info on this problem on a 4.3 like mine. Perhaps it's simply because they are a bit newer and the actuators simply haven't gone bad yet in most.
The problem is the door lock actuator (power door lock motor). One is located in each door and is connected to the door locks. When voltage is applied in one direction the actuator moves in one direction and when the voltage polarity is reversed the actuator moves the lock into the other position. This is how the doors lock and unlock.
The link referenced in my previous post is from an owner of a 4.2 who shows a step by step set of instructions for replacing the actuator module with a new one. Unfortunately, I called Toyota and the door lock actuator for a 4.3 is a bit more than for the 4.2; Toyota wanted $317 for one actuator module. I called junk yards and none had what I needed in stock not to mention a used actuator would likely have the same wear and tear that mine have so they would likely go out in a short time.
I decided to disassemble the actuator module itself to see if I could fix it rather than replace it. Upon inspection I found that the small motor that drives the gears that create the locking and unlocking motion wouldn't move when voltage was applied directly to it. I kept voltage applied and spun the motor shaft slightly and it began to work. I retested this and it the motor would not work frequently when I applied power.
I decided to take apart the motor. Once the motor was apart I found that the copper contacts on the commutator (spinning shaft inside) were seriously charred. What should be a clean, shiny set of copper contacts was covered in black marks from wear over time. I cleaned the contacts with really fine sand paper and then finished it with steel wool and it brought the contacts back to a bright and shiny copper and they looked like new. Also ran a Q-tip over the brushes (little blocks that supply power to the commutator contacts). I then reassembled the motor, put it back in the actuator module and tested it. Sure enough it worked perfectly.
I reinstalled the actuator module in the door and reassembled the door and put the panel back on. I then tested the door locks and they work just like new. Since this was a success I did the same thing to the rear cargo door actuator and it works like a charm also now.
The bottom line here is that if you are mechanically inclined you should be able to fix your power door locks for free rather than $300+ each for the 4.3 and $100+ for the 4.2 generation. The hardest part of all of this is getting to the actuator and taking it out of the door (which isn't really all that hard) and then it's just a few more minutes to open up the actuator itself to pull out the motor, open it up, clean it, and reassemble it.
Now for a few photos with a brief step by step.
Much of this is covered in the link to the 4.2 thread in my previous post. The steps are very similar for removing the actuator in the 4.2 and the 4.3.
First you need to remove the door panel. This can be done by simply prying it away from the door. It is only held on by plastic clips and 3 screws. Pry off the plastic cover on the door pull (handle). Under it there are 2 of the 3 screws. Then pry off the small plastic plate under the door opening lever. This is just snapped in and out with care. Once it's out you can see the third of the three screws. Now that those are removed you just pry the door panel away from the door. I found it easiest to start from the bottom middle as it's easier to grab there. One it's off you can unplug the power door lock/power window switch and any other switches that might be holding the panel to the door. You will also need to remove the two cables (one for locking and one for opening the door) from the interior door lever/lock mechanism. Just rotate the cables to the slots and lift the ball out of the hole and they will come out. Then you're left with this:
Next you will have to pull back the plastic film that covers the back half of the door. It's just held on by a reusable, sticky adhesive. Careful not to stretch or tear the plastic.
You have done this to expose this hole so you can access the actuator.
If you look inside you can see the actuator bolted in place. It looks like this:
First you need to unplug the plug that goes into the actuator in the circular hole in the door. Then you need to disconnect the locking rod from the door handle. You will rotate the yellow clasp up and to the door panel side of the door (inside side). This is the clasp still attached to the locking rod:
The following is the yellow plastic clasp rotated off of the locking rod. Once the clasp is off of the rod the rod will slide out of the hole it is slid into. It won't slide easily, it snaps into the hole so you will need to use a bit of pressure. If pulling isn't enough, there's a plastic cap on the edge of the door above the door latch that can be removed and then you can push the locking rod out of the hole with a screw driver while pulling it from the other direction. What ever it takes to snap it out of that hole. Once it's out, you lift it up and it will slide out of the hole it rests in at the actuator.
Now that the locking rod is removed you can go to the edge of the door where the door latch is. There are 3 torx bolts that hold this latch into place against the door. Unscrew and remove these 3 bolts.
Once that is done you can remove the actuator module. It may be necessary to unbolt one 10mm bolt to loosen the bottom of the window track so it can be swung out of the way to allow the actuator to pass it and come out of the hole.
Once the actuator is out you need to remove the only 3 phillips screws from the exterior of it. Then pry the two halves of the plastic case apart by unclipping the clips around it one by one while prying the case apart all the way around. You will also need to use a razor blade to cut along the seam where some foam rubber is on the exterior of the door latch mechanism so the two halves will be able to separate. Then you slide the latch mechanism (metal latch part) out of the actuator housing (plastic part).
BE VERY CAREFUL WHEN SEPARATING THE TWO HALVES OF THE PLASTIC CASE!
There are a few levers, gears, and springs inside that can just pop out if you aren't careful and then you have to spend an hour trying to figure out how they were in there like I had to do on the rear cargo door actuator which is a little different than the driver's door actuator which I did first.
Once it's apart it will look like this:
Now you need to remove the motor. It just lifts right out along with the gear that's attached to it's shaft. There are two little metal contacts that stick into the bottom of the motor, that's how it gets power. Just lift it right out of it's place and it will be disconnected from these connectors. You can now slide the gear off of the shaft of the motor.
You might be thinking that you can just buy a new little motor from Toyota but I called and they don't sell the little motor, just an entire new actuator module. I also called a local electronics place and they were unable to help with a replacement motor. The numbers on the motor are pretty useless for cross referencing the motor and finding a replacement. No biggie, you can just fix it for free in lest time than it takes to get to the dealer and back anyway.
Here's the motor taken apart:
To get to this point you need to pry out two little metal tabs that are part of the motor case that are bent in to hold the plastic cap on the end of the motor. I had to gently clamp the motor in a bench vise and then I used a small flat bladed screw driver to bend the tabs out. Once they are both out, the cap will slid off and the three parts will just come apart. You should be careful when sliding the end that goes into the plastic cap out as there are electric contacts called brushes in there that are delicate.
You can see the brushes below. They are the little blocks on the end of the metal spring arms which press them against the copper contacts on the commutator (shaft of the motor). As I said earlier, you can wipe these off with a Q-tip to get any corrosion or dust off of the face of them that touches the motor's copper contacts.
Here's a shot of the copper contacts after they have been cleaned. I didn't get a shot of them when they were dirty but just picture them black and covered in corrosion. Nasty.
I took off the little, tiny washer on the copper contact side of the shaft in order to clean the contacts easier but if you choose to take it off, be careful not to lose it.
Now that you've just fixed the root of the problem of your door locks not working, you can put it all back together. I didn't take photos of this process and won't do a step by step on the assembly because if you were mechanically inclined enough to successfully get this far, you will have no problem putting things back the way you found them. Just reverse the order of all of the above. I will mention though that I had to use a screw driver and a hammer to bend the tabs back in on the metal casing of the motor to hold it all together again.
I hope this is useful to some of you as a free alternative to replacing the entire actuator. It would have been easier to replace the actuator but at $317 each, I opted for the extra few steps it took to fix the motor since I had two actuators out.