Yes, I have read all threads about power rear window problems and nothing seemed to match mine. Any input would be appreciated.

Mine is '03 4Runner Ltd and I have had for 7 years now. About 4 months ago, I was driving down the block and noticed that my rear window was going down by itself even though I had not pressed the button. It stopped on the half way down - no matter how I tried, it would not move up or down. An hour later after running into Costco, I decided to try it using the key flop and it rolled up fine. In the second week of July this year, my rear window rolled down by itself overnight - I thought that I accidentally press the key flop without realizing it. So, I started the car and pressed the button to roll it up. When I closed the door, I saw the rear window rolling down by it self again. By then, I have tried numerous time to roll it up, it decided not to work at all - yes, I tried to reset, all-lock button, etc. I brought it to the dealer, they had diagnosed the prob and all connections were fine. The weird thing is that when they hooked the rear window power harness to their master harness, the window was working fine; reconnected the vehicle harness, it was not working - diagnostic showed that both connectors were fine. They had to contact Toyota directly but no avail. The tech decided to close the rear window and unplugged the harness so the rear window would not act on its own mind.

Have anyone run into this problem? Thank you very for all inputs.

Michael

Haven't come across this before on this board. You are unique!

The motor only moves when a contact is made, or in this case stuck, on. See the attached wiring diagram for the circuit. I'm no expert but let's diagnose alittle.
Do you recall hearing the long beep the first time it happened, as when you use the fob button?
I'd like to rule out the Back Door ECU because that would have come up as bad during the Toyota diagnosis.
I'd like to rule out the rear key hole switch because it is a 180d switch but I'm not sure.
Same for the dash switch but still not sure what kind of internal contacts are there. Someone on this board had a faulty dash switch not too long ago.
I'm thinking the key fob may be making contact and not letting go but then you would hear the long beep.

Attached Images

194 037pw.pdf (75.1 KB, 686 views)

First of all, I would like to express my appreciation for time, effort, and knowledge to help me out.

To answer Kmvreter:

- I did not hear the long beep when it first happened using the key fob.
- I did use the key hole switch to open/close the rear window but nothing happened.
- I thought the key fob got stuck too, and opened it, examined it, replaced the battery. Finally put the old key fob away, used the new/spare one came with the purchase. But it had no effect at all.
* The strangest thing I forgot to mention was that when I was out and in the car, I locked all doors using the 'lock all' button on door panel and the key fob--> all locks automatically popped right out open. It does not matter how much I locked all, they popped right out just like fire cracker popping.
* I knew that the Toyota dealer Tech was just a mechanic - so I asked my co-worker who was an electrical engineer to check the wiring. He was knowledgeable about car wiring as well. But... he suspected the faulty lying on the wiring harness on rear window which contradicted to the dealer tech's diagnostic.
* At first, the Toyota tech thought it was the malfunctioned ECU. He ordered a new one; replaced it. Nothing changed - they had to put the old one back in. I had to argued with them so I would not be charged for it.

Currently, they disconnect the harness so the rear window will not act on its own mind and so does the rear wiper.

-Michael

Sorry to dig up an old thread, but this is THE exact problem I am having with my 2004 4runner and I was wondering if you replaced the entire back door harness. I finally must face my problem and fix it because it drained my battery. I had taken out the back door fuse, so that the back window no longer works, but all the passenger doors are constantly unlocking and slowly draining the battery.

2 months ago I traced the power from the fuse panel back to the back door ECU and everything checked out, but the rear window still never worked. I finally jiggled the back door harness where it connects to the ECU and the window miraculously worked. If i remember correctly I actually traced it to the yellow wire in the harness. I was hoping for warmer weather before I tackle the issue once and for all, but winter doesn't want to give up in Northern Wisconsin!

My 3 options are to 1) take it in and have the dealer ream me to fix it 2) just buy a new back door harness for $157 and hope that fixes the problem or 3) try to adjust the pin connectors thinking that they got opened up slightly causing a weak connection.

I had this problem and it turned out to be my battery..... Window would go down on its own at random times and at times the rear wiper would run on it's own as well.... Replacing my battery fixed it..... Not sure why but it worked but am thinking it must be something to do with the control logic when the battery voltage falls below a certain value....

Bob J, I never considered the battery as being a possibility. This is a new to me 4Runner and I am embarrassed to say I never looked at the age of the battery. I assumed too much when I purchased it from my Toyota dealer.

The "0" and "March" are rubbed off on the batter, so would that mean it is from March 2000?! That seems hard to believe. I just fully charged the battery and have access to a load tester, so I will be testing the charging system and battery this afternoon and report back.

Well, it isn't the battery. The "0" must mean 2010 not 2000. battery and charging system did fine on the load test. When I get the chance I am going to go over the back door harness real good and maybe try to take the one wire out of the adapter and try replacing/repairing it's connector.

Hi mracko,

I brought mine to to the a couple dealers and they could not find the problem. Some said it was the module control ($300); some said it was the sensor ($20), not including the labor. Finally, I made a deal with one dealer near my workplace that if they found the problem, I would agree to anything they charged; if not they would not get a dime. They held my car for a week, of course they gave me a loaner and finally found the problem - they replaced the actuator, believed to be by the driver side door. The problem was gone for good. The actuator controls the on/off door locks as well as the windows.

Hope this will help.
Michael

Hi Michael,

That information helps a lot! t gives me more information of what could be the problem. Sorry to hear you had to go through all that to get it fixed. It seems like it is one of those problems you can throw a bunch of electrical components at and hope it fixes it. I am hoping to stay away from that method of repairing, especially given the price of each component. I You never mentioned it in your original post, but did your door locks every automatically unlock too? Mine, at times, constantly unlock. it will go in spurts. It won't do it for a bit and then all of a sudden it will do rapid bursts of unlocking.

I originally thought the two problems might not be connected, but after reading what your problem turned out to be, they must be connected. It almost seems like a safety feature; when power is lost the doors unlock and the window opens. I'll have to research the actuator in the driver's door and try to diagnose the wiring.

Thanks again for that information.

Hi Mracko,

The door automatically unlocked at time and it would finally go in to burst, indeed - you were correct as I forgot to mention in my original post. After the actuator was replaced, the problems were gone for good. The actuator costs somewhere around 10-20. Hopefully you can diagnose your problem sooner.

Michael

PS. sorry as I did not check my email regularly to see your question.