I was able to get the liftgate open by releasing it through the small access hole on the inside and using a pair of needle nose pliers. I do not hear anything from the liftgate when the power locks are activated but all other doors work fine. I pulled the connector off the actuator motor and don't measure any voltage on the plug at all, even when someone is activating the power locks.
There is nothing listed in the fuse panel for power locks at all, and all fuses look ok. The iod fuse was corroded but I replaced it. Any ideas?

 

Welcome to DF
If you don't have power at the actuator, then you may have an open circuit.

 

 

Ok, let's see how complicated we can make this. In the diagram above is the switch that you push in the liftgate to open the liftgate. It sends a signal to the Body Control Module that you want the liftgate open. The BCM checks to make sure the doors have been unlocked and then sends power down the wire in the first diagram to the latch release solinoid. So when you check for power at the solinoid, there won't be any. Unless you are pushing on the button on the hatch or your key fob. You pretty much need a scan tool to see if the BCM is seeing the switch input but I guess I've seen enough of the hatch switches corroded that I would feel pretty good about replacing it. Hope this somewhat helps.

 

Thanks for the replies and the diagram, I do have to correct what I wrote earlier. I now realize that the bcm controls everything and that there are 2 actuators, one to unlock and one to release. I now see 5V to one of the actuators (apparently I was not getting the meter probe to make contact earlier) but no activity when the lock switch is activated. Could that be because the liftgate is open when I am checking? I will have to do some checking with the liftgate closed.

If the problem was the release switch above the license plate, shouldnt I still hear the actuator try to unlock? Hopefully I will have a chance to check it out further this weekend. I am starting to suspect the locking actuator is faulty. Unfortunately the key lock is not working either.

 

As far as I know, there is no lock actuator. Everything is built into the latch. The ajar switch, the release actuator and the cinching mechanism if you have power liftgate. The rod from the lock cylinder goes to the latch. When you squeeze the switch in the licence bar, the actuator should release the latch even if it is open. The 5v you are seeing is probably the door ajar switch wire.



LIFTGATE AJAR SWITCH (POWER RELEASE) - BLACK 4 WAY

CAVITY 1 Z78 20BK/OR-GROUND, CAVITY 2 G78 20VT/OR-LIFTGATE AJAR SWITCH SENSE, CAVITY 3 P31 20TN/YL-LIFTGATE RELEASE DRIVER, CAVITY 4 Z231 20BK/YL-GROUND

 

Ok, that makes sense because I couldn't figure out where the ajar switch was. I removed the 3 screws and took the whole assembly out of the liftgate, it sure looked like 2 separate actuators but I must be mistaken. So I likely won't hear anything when the power lock switch is activated, it just lets the bcm know that it is ok to enable the release switch? It does not have power liftgate for the record.

Thanks for your info Tizzy1, it has cleared up a lot and your diagnosis of a corroded switch makes more sense now. The van hasn't been home much so hopefully Sunday I will get back at it.

 

just like to ask what is the probable problem if your rear door is open and the indicator light in the panel is not lighting up. When I press the release latch it is not opening either. I can only open the door using the key. Is there a fuse for this actuator or door sensing mechanism? Hope to hear from you soon.

 

What year you dealing with? If it is '01-'07, the above information should be pretty accurate. The door ajar switch and the release motor are in the first wiring diagram and both are supplied what they need from the BCM. They both are supplied power and ground at the latch itself so maybe it is all corroded and not getting a good ground.

 

mine is '06. I'll take a look on the grounding this weekend. And if the grounding is good. Do I need to check also the voltage for terminal 1 and 2 & 3 and 4?