FWD Gremlin

Kind of long story but I’m befuddled and wonder is anyone could offer some advice.
2011 Tacoma, 4 liter, automatic. Mileage 195K. Recently re-geared to 4.56. Did the complete break-in properly. Everything checked out fine at 600 miles. No diff fluid replacement as shop said things looked good.

Did a pretty rough off-road trip. Lots of time in 4-low and had to use the locker several times. Several very muddy puddles. Came off the trail and put it into 2-high. It came out of FWD but the green FWD icon kept flashing as if it was in 4-high but not engaged. And, if I tried putting it into 4-high or 4-low nothing happened. Figured I might have muck in a plug in the transfer. Got home, cleaned up, got underneath and everything was fine. Pulled the plugs apart and cleaned just to be sure. Also found that if I shut it off, moved the selector to 4-high, and started it, 4-high and 4-low worked fine.

Took it to Toyota (have been going to this shop for 15 years). Not the place that did the re-gear. At this point it’s about 1K past the re-gear. Figured they were going to tell me new actuator. After it had been in service the service rep brought the technician out to talk with me. Said when he got it, it exhibited all the symptoms as described. Once he put it on the lift and got the tires off the ground everything went to normal.

He opened and inspected the front diff, rear diff, and transfer. No sign of anything broken or in need of replacement. Rear diff oil was a little dark and some metal flecks. All new fluids and I went with him for the test drive. Everything worked fine. I drove it home and everything was fine.

The next day I start it up in 2-high and that damned icon was flashing me again and it wouldn’t go into FWD. After playing with it I found that if I just turn the key to “on”, don’t start it, and the icon is not flashing, I can start the truck and everything is fine. If I turn the key to “on” and the icon is flashing, and then move the shifter from Park to Reverse or Park to Neutral, the icon goes out. I can then start the truck and everything is normal.

This doesn’t happen all the time. Can go for days w/o the problem and then the gremlin comes back. I am completely befuckled. I appreciate any help.

Thank you all!

 

It’s probably an actuator issue.
See the video here to diagnose which one - https://www.tacomaworld.com/threads...or-t-case-actuator.358059/page-2#post-9684761

Then read through this link diagnose the the problem.

My first guess would be the Front Actuator. But that’s just a guess.

 

Thank you for the reply!
I went through that thread when the problem started. However, when the wheels are off the ground everything works as it should.

 

If everything works as it should. It’s almost like it isn’t sensing one of the limit switches.
Will it go into 4LO?

 

If the FWD icon is flashing when it's in 2-high it will not go into any 4-wheel state. If the icon isn't flashing in 2-high, 4-high and 4-low work fine.
Because of the way I can get the icon to stop flashing I think it has something to do with a sensor. But I am no way familiar enough with the mechanics of the truck to have any idea beyond that. But now I'm going to research Tacoma limit switches!

 

Hah!
T-SB-0066-12
April 25, 2012
Automatic Disconnecting Differential (A.D.D.) Shift
Actuator Inoperative

 

You might be able to pull the cover off of it and inspect the internal components.
It’s worth a shot always.
https://youtu.be/ZJESG91GbCQ