Seems my front diff switch is is dying as well. Took it out and sometimes it would test fine and sometimes not. This thread has saved me a ton of time wild goose chasing my 4wd issue. Thanks a ton.

 

My wife has an 02 4runner and we're having the same problems, but our system doesn't look like everyone else's here.... so a little fyi for those with something similar to what we have:

our actuator on the transfer case has a flat 6 connector. the two pins closest to the motor on the actuator are what you have to apply 12v power to to manually switch it in and out of 4wd.

for the life of me i could not locate the sensor on the front axle. The dealer has a really poor schematic that seems to indicate that there is one on the front, but again, I'm no slouch and I couldn't find it. maybe it is located within the actuator?

We have two sensors on top of the transfer case that you can access from the left side of the truck and two on the back, on the actuator.

It appears that one of them has gone bad -- the one towards the front of the truck. The dealer just charged me $95 for it.
unbelievable.

I'll report back if it fixes our problem.

 

Doug,
I hope you're still around and being a savior to most 4runner owners...just that my questions are still in limbo and would still really appreciate some pictures...thanks!

 

Pretty sure these are the ones;

 

thanks a lot Godzilla, are the circled parts the units to replace?

 

Not everyone's 4runner had that same faulty front diff switch. (although it is a prime suspect) Best to test yours first before potentially replacing a good switch and still having the same problem. I nearly did...but mine was working fine on the continuity test.

 

How come my connector is 2 rows of 3 - not flat 6?

Anyone got any info on refitting the 'gear/solonoid' inside the actuator itself?
Mine fell out when I opened the actuator to test the terminals - the 4 out of 6 wires that run from the connector.

Ash.

 

Are 84222-12010 and 84222-35070 good part numbers for a 2000 Limited as well? My light just started flashing today and the 4X4 is acting up. I think the sensor is the problem. Thanks

 

Great post - should be Stickied - I printed hard copies already!

 

maybe you have to grease your 4x4 parts? I had that happen to me so I went and got it greased...the "clunk" became a little 'ol klink' barely noticeable anymore. Feel free to correct me if i'm wrong guys.

 

Everything is greased up. The "clunk" that one gets in the drive train does get eliminated by regular greasing.

 

Well, it worked -- 4wd works just fine now, finally!

A word of advice -- don't just start replacing sensors because some people's are bad. they're a simple test. you pull them out, and check for resistance between the two pins in the switch, with the ball end out and pushed in.

the rear switches are a quick, easy pull and check. a 22mm socket on a ratchet, with the ratchet positioned above the drive shaft makes pulling them easy.

edit:
regarding the connector on the transfer case actuator, ours is an 02 with a flat 6, the older ones seem to be a 6-pin, but with 3 on 3.

 

What do you mean by "regular greasing"?

 

prolly once a season especially if you go to the snow or 4 wheeling, some thing like that I suppose.

 

Everyone can view the 4WD system photos in a group album I created on my Photobucket account at this address;

http://photobucket.com/toyota_4runner

 

thanks 99sc4runner,

Emailed you a couple of weeks back - glad you're still around. Thanks for the doc's.
Could you please forward the rest of the 2-4 selector system manual pages if you have them.
I have these, but for the 'flat 6' connector type. My 4runner needs your '2 rows of 3' info.

I am trying to piece together how the actuator rotor aligns in each mode - mine popped out during t/shooting and I have no idea what angle it goes back in at.

Much appreciate

FWIW I have the 'flat6' version in pdf of the 2-4 selector info if anyone needs it.

ASh.

PS. this is what the rotor looks like that is driven by the electric motor (the black plastic part of the actuator) and in turn, moves the shaft to give 2wd, H4F or H4L

 

I replaced both switch. The light still flashing.
After ran for a while, I shift the gear, go up and down the hill and run for about 2 week. Suddenly, the flash was gone without my notice. And I feel that the truck is in 2wd mode now.
I am will not touch the 4wd button for now and just leave it alone. Because I am not sure the 4WD is fixed or not.

 

is it normal for the 4WD to disengage with a clunk? or is it supposed to be subtle? Any ideas of why there is even a clunk? cause mine does this......

 

Hey, I registered on here for the sole purpose of saying thank you. My 99 Limited was experiencing the same thing, stuck in 4wd with light flashing. Replaced both sensors and it works perfectly now. For me it was the front switch, part 8422-35070. I too was told that a motor was dead and it was going to be 2 grand to fix, which for a college student is pretty much a shot to the...some place you wouldnt want to get shot...Anyway, thanks all for the info these sites are really invaluable. If anyone has any questions about this whatsoever don't hesitate to PM me.

Take care,
Colton

 

I have a 2000 runner. I replaced my old engine with a used engine at Toyota Stealership, when I get it back, the front diff will not engage, no 4WD light comes on.
4WD worked fine before I had work done to the engine. Is it possible that they forgot to connect my acuators?