No rear hatch functions

Not sure if anyone can help me out or has any ideas. I recently had the back hatch open to install a switch install mod that allows access to the window up/down and door latch from the inside rear of the vehicle. Somehow I lost all function in the rear hatch. The only thing that works is the window up/down with the key. So no rear hatch lock/unlock sound, no hatch release, no wiper function, defrost function or window control from the front counsel. I initially thought it was the rear ECM and replaced it. Didn’t fix the problem. Anyone have any ideas before I dish out $160/hr to Toyota.

 

There's a bit of an information gap between "had the back hatch open to install a switch" and "lost all function in the rear hatch". What all did you do, which may pinpoint where the problem came from?

 

Undo what you did and it may work again.

 

Any advice you get on this forum will cost you $120/hr. That's the "friends & family" discount we offer! Cash up front first, sir.

 

A toyota dealer may simply undo what you did to return hatch functionality. You’d want to be very clear in asking them if they are going to remove the module you installed, or try to make it work.

Best you can do in a situation like this is spend some time trying to diagnose it yourself. Did you let out any of the magic smoke when you were in the process of installing the module? Have you verified that you reconnected anything you disconnected as prt of the install?

Start with checking all the fuses that might be involved with the circuits for the wiper , glass defroster and the lock. These might be in the fusebox under the hood or inside, so check both.

 

Yeah, I unhooked everything with no luck. No smoke that I noticed. I will revisit the fuse situation. Is it enough to just visually inspect them or should I do a continuity test. Everything is connected but I could probably unhook and reconnect to make sure everything is secure. After I disconnect the battery to do any work I sometimes run into a situation where the back window will only go down with the key. Function seems to come back after a few hours …. weird. Just don’t want to get stuck in a situation where my window gets stuck in the down position.

 

Reverse what ever you did.

 

Every fuse you want to verify needs checked with an ohmmeter. Also, did you disconnect the battery for 30 minutes after all work was completed?

 

If the fuses are good, then somewhere back there is a broken wire or a loose connector.

 

The windows can sometimes lose their auto up/down memory when the battery is disconnected for awhile. Usually, they can be opened and closed manually (by holding the button down or up) and they will eventually relearn.


As far as the loss of function, your best bet is to take a very close look at everything you did and you might find a bad connection somewhere.

 

I bet that’s it!!!! It needs to reinitialize. I just made the connection that this happened to me when I disconnected my battery before doing some interior work recently. It was disconnected for an entire day a few different times). When I reconnected it, each time the rear hatch door lock did not unlock and the rear window did not work. By chance I figured out that I had to start the engine and put it park-drive-park, then shut it off. I did that two or three separate times. Then it started working. Not sure which of those actions did the resetting, but I think at least two start cycles were necessary to get everything working.

 

I’ve disconnected the work that I did and tested all the wires. I’m going to go through the fuses with a multimeter tomorrow and try to reinitialize function after disconnecting for 30min. Thank you for everyone’s input, I’ll let you know what happens.

 

I assume this is the mod involving splicing into gray wire #24 from the door ECU and wiring a switch to ground to activate those functions?

Other than what's listed in above posts:

1- I would check to make sure you didn't cut all the way through the gray wire at the ECU, especially if you used a tap.

2 - Make sure you actually spliced into the correct wire because obviously if you are in the wrong (+) wire and you then routed that to ground you probably just toasted your door ECU, maybe a fuse popped to save it, but likely not given the proximity of the splice to the ECU. (Edit on re-reading, I see you replaced the ECU so probably this isn't the issue)

 

I'm still stuck at what mod is this to open and close from inside? I though we had a switch below the gear lever that closes and opens the window.

 

It's a mod to add a switch in the rear hatch area to unlock and open the hatch gate, as well as open and close the rear window, from the inside of the truck, or with a remote.

 

https://www.4runners.com/threads/ultimate-camping-mod-rear-window-up-down-4th-and-5th-gen.6424/

 

good news... kinda. I checked all the fuses associated with the related functions and found them all to be good. I checked all the wire continuity of the wires I tapped and everything checked out. (all modifications are currently disconnected) Reconnected the battery and tried to see if I could reinitialize the window function by turning car on and cycling through park -> drive. Did this process a couple times then rolled all windows down individually and back up ending with the back door window and it worked!! Not sure what that I really changed anything other than disconnecting and reconnecting some wire harness connections to check continuity. So, I now have back window function and rear wiper, and rear defrost. Unfortunately, I still have no locking mechanism sound from the back door and the hatch release doesn't function (I did also check the switch function, and it works fine) When I turn the key in the back door I hear all the other doors unlock but not the back door. Not really sure what to check next. Is there a way to check that latch/locking mechanism?

 

Have you tried putting it back original to see if it works again like that to trouble shoot? If it does then you have found the problem. My rear wiper quit suddenly and I couldn't understand what happened. Started to check fuses and I checked window switch and it was barely down but not noticeable. Your add on might be affecting the window safety system that goes back down that keeps kids from being caught in window going up. I used in channel vent visors and you have to up and down them so they will up with the added resistance. They do that I guess instead of halfway down only rear windows like the olden days. If you did one thing and it creates problems, undo it to correct and trouble shoot. Check fuses after that and be careful of aftermarket electronics. I want a Lite Bright wiring kit so I can run high, low beams and fog at same time, but I worry about creating problems with some improvements.

 

Yeah will definitely be more careful moving forward. I completely dismantled the switch install so everything is back to original. Also checked all wires and fuses for continuity and everything checked out. I was able to borrow a cable from a friend and connect to techstream to see if I had any error codes that might help. No codes but in the active mode the computer doesn't recognize when the hatch switch is pressed. Checked switch function with a voltmeter and it functions when I test it at the ECU-B. Makes me wonder if its a communication issue between the ECU-B and the main ECU. I have already replaced the ECU-B so that shouldn't be the problem. At any rate I think this is getting beyond my ability to troubleshoot.

 

You might reflash the ECU by disconnecting the negative cable for a minute and see if it affects reset.

 

Just an update regarding this issue. It turns out that I bent some pins when I disconnected and reconnected the wiring harness to the back control module. Brought it into a local shop and the tech was able to bend the pins back into position and everything works now works again. Thank you everyone for your input. I also wired up my interior switches and everything is working great!