morrisonjd84

Walked out side to snow this morning to snow so took the 4runner to find out I have no 4wheel drive??? Inspected the vacuum lines that got to the actuator and they looked fine. Took it to the dealer and they say it's a temp sensor located on the transfer case (photo attached) they say there are not positive but pretty sure that's the problem. that's what is causing it not to go into 4wheel Drive. $240 my question is could that be the problem if not what could be the problem? The runner is a 1994 auto 3.0 with stick for the 4x4 not the button. And the light will not come on for 4x4 and it doesn't feel like it engages and front tires not spinning? What could this be.? Well the picture won't attach for some reason but it's a sensor on the side of what I believe is the transfer case looks similar to an o2 sensor with 2wires coming off it. Any ideas would be appreciated thanks

wyoming9

iTrader: (1)

Are you sure it is not a oil pressure switch??

I could not find a temperature switch in the 4x4 system??

****My bad for some strange reason it is a pressure and temperature switch no wonder it is so expensive!!!

Was that the price for the switch only or installed??

morrisonjd84

They said temp sensor was the tech name for it. Price for part was 160 part number
89429-35022

morrisonjd84

I can send you the picture via text or email if that would help I couldn't find anything like it on the 4wheel drive system either that's why I thought it was odd. Email me or number and I'll send it morrisonjd84@gmail.com

wyoming9

iTrader: (1)

Be nice to know where you are?/

Thing is with this stuff if the sensor is bad other issues could as well be unknown to the sensor is fixed.

Your picture is to big that is why it would not load.

Well two choices buy anew one or hunt for a used one!!

Could be you just have mud messing up the connection.

Give that poor 4Runner at good bath!!

morrisonjd84

Boone, NC 15degress right now

morrisonjd84

Any other ideas of why it would not be going into 4x4

Gevo

I don't think this would be a vacuum line issue.. I think this is the transfer case...

I haven't taken that apart yet on mine so I don't know how it works.. but oil pressure may def be the case if it's the same case as mine.

I don't know anything about this sensor/switch.

morrisonjd84

Yeah she does need a good bath but I don't know if that would cause it cause it has worked fine since I played in the mud. Have you ever heard of pressure temp sensor causing 4x4 issues?

Punchy

The sensor on the A340H transfercase is a overheat sensor, Shouldn't have any affect on going into 4WD.


The plug on the on the drivers side of the auto trans controls the electrical for 4WD, Changing into 4H does the following 1. Diverts the OD solenoid pressure to the transfercase section 2. sends 12v to the ECT to turn on OD, to the switch on your ADD diff (This turns the dash light on when it engages) and the two solenoids hanging on the passenger inner fender.
setting to 4L sends 12v to the lock on the transfercase planetary gear.


When you switch into 4L does it go into the lower gear ratio?
Yes?, Then the trans and transfercase is good, So then -
Sometimes the ADD actuator on the diff has a hard time sliding in cold gear oil.
There is a vacuum hose that goes from the intake manifold to the 2 solenoids on the passenger side inner fender, From there it splits into 2 hoses and goes through the compartment wall into the fender, One goes to a reservoir tank then to the ADD diff (The actuator line) and the other goes straight to the ADD diff (de-activator line).
Make sure these all flow good, no damage or leaks.


No?
Unplug the connection on the drivers side of the trans and make sure the plug and trans connections (terminals) are clean and follow the wiring over the trans feeling for wire damage (don't pull to hard as there is a harness plug connecter on top that can come apart and is a pain getting back together blindly).




If you have the A340F (manual transfercase) with the same problem then it is 90% likely ADD vacuum lines issue.

Punchy

I just looked up more info (rumors) on the transfercase temp sensor but cant get specifics but it might be a shunt off as they say, That would be scary if you in a tight spot and 4WD shuts off when in need.


I would think ether way you could pull the plug and short wiring plug, This will ether turn the dash light trans overheat on or it will allow 4H and 4L to work.

morrisonjd84

Can anyone help me find this part cheap and from a reliable source thanks guys

Gevo

Morrison, did you test it to confirm that it is not working?

I read through this thread but I didn't see that you pulled it out and tested it.. perhaps I missed it.. But I recommend to do that first. I replaced a couple of sensors as I have been rebuilding my 4runner, but I also found the old ones are all within spec. I held on to them for future use I guess.

Otherwise, your best bet is ebay.

morrisonjd84

Well it needs to be replaced anyway because one of the wires are ripped out of it I just didn'tsee how this sensor could affect 4x4 but iI've been all through the a. D. D. And haven't found a problem with vacuum although the ssolenoid closest to the windshield with the vvacuum is not sucking air. Any thoughts?

Gevo

Well, the solenoids are relatively easy to test, if you aren't able to test it with the FSM instructions, im sure we can help you there. If there is no vacuum coming TO the solenoid, that problem is further up the line. Also, the ADD takes very little suction to move, so you can actually test the engagement with your mouth.

This is what I would do. Jack the front end up, both tires in the air. Put car in 2WD, both tires now should be free of eachother. Suck on one vacuum line, then try to spin the tire if still free spinning, suck on the other vacuum line and try again. Assuming your actuator is working properly, this should be enough pressure and on suction to one of those lines you should get the axle to engage and both wheels will now be connected.

COnfirm the vacuum lines are going to the right places on the VSV's.

This test may eliminate your ADD from the list of possible suspects.

If I made a mistake here, someone please point it out, but I tested my own system exactly this way

scope103

The part number you were given IS the temperature switch. http://www.toyotapartsoverstock.com/...rm=89429-35022 Should be around $110 for the part OEM. I'm "pretty sure" a failure of that component won't keep you out of 4wd (but the indicator runs through the ECM, so it may keep you out of 4L).

So as others have said, you have to work through the ADD system to find out what's not engaging. (What do you mean when you say "I've been all through the a.D.D. And haven't found a problem"? You've got a problem (no engagement), what have you found?)

morrisonjd84

i will try Gevos advise as soon as i get home and let you know the results as for being all through the A.d.d. maybe i worded that wrong what i meant was ive been through all the vacuum lines from two connections under the hood to the tank under the fender and down to the accuator and have found no leaks or cracks or any signs of wear for that matter. i did try to engage it with my mouth but i did not have the front tires off the ground.

scope103

That's all good (I apologize if I sounded harsh). The next step could be to pull each of the vacuum lines to the A.D.D., and with someone else switching in and out of 4wd feel for vacuum. If that isn't right, work backwards to the VSVs. If it seems right, work forward to the A.D.D.

Good luck!

Stuwy123

iTrader: (1)

If you don't want to drop $240 on a new sensor, just find a wrecking yard and pull one yourself. It'll cost you maybe $15 at most.
When it gets really cold out here, the front diff takes a bit to engage the ADD front diff.
If you want to test if you have 4wd or not, find an icy patch on the grippy road or gravel. Drive the front end off the ice and onto the high grip, leaving the back tires on the ice. Put it in 4x4 and punch the gas. If it takes off nicely and smoothly, you have 4x4. If it's sit there and spins the back tires for a bit until you hit grip, then you only have 2wd.
It's a low tech method but it's easier than pulling out the floor jack and cranking up one front wheel.