06 Tacoma stuck in 4wd

i too have also done this as well. It worked for me for about a month, then it started acting up again. I ended up bringing my truck to the dealership and telling them the situation and they had me swap out the old actuator with a new one. I just took it home and installed it myself and havent had an issue since then.

 

thank you I see,

 

So last night we went ahead and pulled the front diff actuator thinking it could be the problem and hoping it'll be the fix.
it ended up being in pretty good condition. clean no dirt the prongs were in great condition touching each other and tested the actuator and it was working fine. so we went ahead and sled the sliding sleeve located inside of the front differential from 4wd to 2wd manually and lined up the fork into its place and put back on the actuator and connected the vacuum line and the plug.
After that my 4wd indicator light on the gauge went from slowly blinking to quickly blinking with 4lo light blinking together simultaneously.
Then went ahead and put it in reverse and drive going back and forth straight with the switch on 2wd position to see if it was in 2wd which it was. then turned it to 4hi position and 4lo position and went forward and reverse with no luck of it engaging or disengaging to 4wd. so now its "stuck" in 2wd drive and wont engage back to 4wd.

What would be the reason for that? would it be because we manually put it back into 2wd and the transfer case is in 4wd still ?
so we think its the transfer case actuator. we pulled the black cap off not the whole actuator itself from the transfer case and found no motor and had a little water in it from condensation build up were thinking since were in northern California with snow and very low temp for this time of year, then replaced it back.

So before tearing into anything else wanted any help or advice on taking the actuator off the transfer case , the location of the motor/components of the actuator or should we even try messing with the transfer case at all ? read a lot of threads and post saying it wasn't a good idea to tear into it or it was difficult.
Is there are any links or advice , diagrams ,schematics etc. on the transfer case actuator itself?
or if anyone has ran in to this problem ?

 

so your front diff actuator was working fine while it was apart.
then you manually put it in 2wd and put everything back together, then the lights on the dash started acting up. have you thought about maybe going to a toyota dealership and have them hook it up to the diagnostics machine? just to see if it throws a code or not.

 

Could be your 4wd ECU is acting up. I've attached a complete file for the 4wd system.

 

i have not yet tooken it to a dealership. trying to pinpoint and trouble shoot before i go back into town which is 2 hours away.

 

thank you !!! for the help and diagram i will be checking that out today as well

 

No problem. The 4wd ECU is tucked in behind and to the right of your glove box. I'd probably start by confirming you are getting the correct ground signals in connector B for the H2 position if that is what you are currently stuck in. Can also confirm if the ADD and transfer shift motor are getting power when trying to engage H4 etc. All of it can be checked at the ECU since all of the relevant wires go there.

 

awesome !! i was reading a few threads about that but had no clue what the TL1 TL2 TL3 meant but with the 4wd system wire diagram i see what they were talking about now. if theres any more advice or info you could give me id truly appreciate it.

would you happen to know if we were to pull the diff front actuator back off and slide the sleeve back to 4wd drive . and put back the actuator on the front diff would it go back where i started withit being back in 4wd and stuck there?

 

Do you know anyone else with a Tacoma nearby 05-09? The fastest check would just be to try out a different ECU which is literally as easy as plugging in two connectors. The ECU itself is about as big as a mid sized book and can be swapped out in a few minutes.

 

There really isnt anyone near by with a 06-09 tacoma that be great if there was

 

Hmm, if it's going into 4Low that rules out your Transfercase actuator. must be your Front diff actuator or the signal going to it (wiring, ecu etc). I believe there is a way to manually shift it, i'll try to find the post.

 

Well if your up for some testing here is where you should have ground going to the ECU from the limit switches for each state:

H2





H4



L4


As @Pabloeeto said it could just be wiring... as simple as a limit switch not sending the correct signal and now the ECU doesn't know what to do.

 

it did go into 4 lo when it was stuck in 4hi with my original problem of being stuck in 4hi but it did go in 4 lo at that time. we pulled the front diff actuator and open it up and everything was in good condition. and we did manually moved the sliding sleeve in the front diff from 4wd to 2wd. and it flashing with 4lo icon quickly.
thank you

 

i am up for testing forsure just would like a how to to go about testing.

 

If it was me I'd probably test both motors by applying power and ground and make sure they are shifting properly. If that checked out good then I'd test those ground signals I listed above with a multimeter. If the motors operated fine and all the correct signals were going to the ECU then I'd be looking to replace the ECU.

If the motors didn't move when powered then you either have a bad connection or a faulty motor.

If not all of the ground signals were present you would either have a faulty limit switch, wiring or know that the shifter was not making it all the way to it's destination for some reason. Depending on which ground signal is either not present when it should be or present when it shouldn't be would narrow down your search.

This file gives a bit of a breakdown of the sequence of events when you are shifting.

 

This might will be helpful if you want to test your actual 4WD switch and the shift actuator.

 

Thank you again!! we'll be testing all of this today and will let you guys know whats going on or what we think is going on. any more advice or help will be great if you can

 

You're welcome. After reading everything that you've experienced it sounds like your ADD may be stuck in the locked position, but that is just a guess. It wouldn't really explain the 4lo light blinking though. Good luck!

 

so i ended up bringing it to a shop and low and behold it was he front diff actuator which we figured it could and would of been cost me about 700 with part and installation
the motor on it worked great !! but the worm gears inside was doing a full 360 when switching from 2wd to 4wd 4hi 4lo. which i was told it should of only been going/spining like a 180 either to 2wd or 180 in the other direction to 4wd.

but now after two weeks my check engine light is on?
trying to get to the bottom of it tonight.

thank you everyone for the help and the late update.