Question - on the 2001 - 2002 4x4 4runners, with electronic actuators and push button 4x4 on the fly - is the front driveshaft always locked and spinning even when in 2wd? I have verified front wheels are not spinning - so front differential is not engaged - nor does it engage with push button either.

I am having the flashing 4x4 lights and no engagement in 4x4 Hi or Low - without manually jumping, with a "U" shaped wire, the forward most transfer case actuator ball-sensor harness - by doing this, I can get 4x4 engaged, with lights flashing - and I can switch to 4x4 Low with differential locked, and all lights will go solid. Once going back to 2wd - the lights remain flashing.

I already removed and cleaned the cover contacts for the center differential actuator, ordered and installed a refurbished $350 4x4 computer module, installed new AISIN front differential actuator, changed both differential and transfer case fluids, and both transfer case actuator sensors are new OEM Toyota.

I believe I have narrowed it down to a wiring issue OR a mechanical differential actuator rod/fork issue I believe - to further diagnose wiring, I need to rule out mechanical - I do know also, that when I remove the harness pigtail for the rear transfer case actuator sensor, the flashing lights stop - so maybe even adding a washer to that sensor will fix it, as someone else did on Yotatech.

Question is - on the 2001 - 2002 4x4 4runners with electronic actuators and push button 4x4 on the fly :

IS the front driveshaft always locked and spinning even when in 2wd?

No, in 2WD, the front driveshaft should spin freely by hand (disconnected at the diff end and the transfer case end). It might spin slowly when driving at speed due to viscous drag in the front diff, but it is not directly linked to road or driveline speed otherwise.

It sounds like your transfer case actuator is not making it all the way to 2WD and that's why the 4WD ECU keeps the lights blinking.

-Charlie

Ok, that is what I thought - heard a few people say it was normal for 2001-2002 shift on the fly 4runner 4x4's - but made no sense to me as the Tacoma's front that year spin freely. I manually activated the transfer case actuator both ways and can never get it to unlock that front driveshaft.

Anyone have a good shop that rebuilds transfer cases???

Those people may be confusing the multi-mode transfer case for a full-time transfer case (like you have in the GX, or V8 4th gen 4runner, Land Cruiser, etc.).

-Charlie

That's exactly what I thought - thank you for helping me confirm!

Can confirm what Charlie said. When I greased my joint fittings on the front shaft last year I remember turning it by hand. So nice & easy.

I drove through water once and it rusted the lines on the transfer case for the acuator. I ended up just getting a used transfercase from a junk yard for like $300 cause that was the easiest. both front acuator and transfer case acuator should move when shifting to awd/4wd


have a friend under the car near the transfer case acuator and see if thats at least moving. if not then its not getting the command or its not being sent.

Mine would move but since it was rusted it didnt know when to stop and got all confused.

So, that gear does come out, rather easy - the housing can then be removed, and the rod can be pulled in and out.

I have fixed her, this posting explained what I found to be essentially true :

4wd not engaging in my 2001 4runner

There are some differences in what I did, but she is now fixed - I do still have to turn the wheel and move in D or R to get from 4wd to 2wd, but it's fixed.

DO NOT BE AFRAID to take the gear out of the housing, it is a serviceable actuator, like the 2000 and older models, just has the rod metal gear attached to the plastic actuator gear wheel via a metal tab and spring roll - it does com apart and is fairly easy to put back together - pull it all out, re-clock, move rod in/out where neeeded, and bam.

Even on a j-shift you often have to be moving or change the loading on the drivetrain to go in/out of 4WD. It could just be the front diff actuator being loaded a bit to keep it from sliding.

Use it more and it will get better - Just go in and out of 4WD every time you drive it on a straight section of road until its working quickly and reliably. After that, use it at least monthly (owners manual requirement).

-Charlie

I try and go in and out of 4x4 at least a few times a month. This seems to keep the sensors free and working properly. I’ve noticed if I don’t, it will take a few tries to get it in 4wd. I replaced a few of the pressure sensors on top of the transfer case and this helped a lot.

Living in a subdivision that has all dirt/gravel roads is really handy for that. I drive a few miles in 4WD once a month like clockwork. A little 4LO, a little 4HI, shifting through the gears in both, keeps the truck happy.

Come winter, if I encounter snow/ice the truck shifts happily in/out of 4WD as needed. It's like, when I shift it into 4WD, I am going into "double gravity" mode. It just grabs the ground, and away I go!

The Toyo AT3 tires seem to help a lot, too. I ran into a rainstorm the other day on the way home from a Dr. appointment. I mean a RAIN storm. It was pouring down like mad. I slowed down to about 45, and had no trouble staying in what little bit of road I could see. Come time to slow down for a 90* turn, and the truck had no problems at at all. I think the ABS system was working at it's peak

Have a great day, gang!
Pat☺