freightdogfreddy

The 20A 4WD fuse at the fusebox is good it's one of the first things I checked. If only i could be so lucky

TheDurk

Yep. Use a test light or meter. One probe (black if meter) on the pin and the other on battery positive (clamp if test light). If it lights up or shows 12V, you have a good ground.

freightdogfreddy

Sounds easy enough. If it shows 12V, the switch on the T/C lever is working. Im 99% positive it is but I'll check. I'm tired of this 4runner been nothing but problems only 99K miles. New AC evaporator, New shocks, new brakes, new valve cover seals (they were leaking, I PAID a guy to do that, it was a big job). It still idles kinda high now this 4WD nonsense. I'm close to done with it

99SC4Runner

On the 99 t-case there are the center diff lock position switch, the neutral position switch, and the L4 position switch. They are all the same switch, and I still have a brand new Toyota switch for sale that replaces any one of those switches. I'd take each switch out one at a time and test them to rule out any connectivity issues with those switches. Then remove the switch on the front diff and test it. If you're getting your actuator to move into 4wd and back out into 2wd successfully, then I'd think your actuator is fine.

ManyMods

Wishing all veterans out there a grateful day this Memorial Day.

Well, I had to laugh as I was reading through these thousands of pages on our mutual 4wd problem. Maybe we should all wise up and start buying Fords? LOL

I have 106K on the clock and have always babied my Yota, not that I don't use it on and off in 4wd, but I have never taken it over sand and I keep it clean inside, outside and under. Anyway, the much talked about 'stuck in gear' problem hit me 10K ago and after being towed to my dealer and spending ~$1500, I had 4wd, but it seemed to be sluggish and intermittent in the speed in which it engaged. At the time I did not think much of it since I don't use 4wd that often.

Finally, like another brother's post I read earlier, just as I am getting ready to sell the 4R -- and have had two offers at $10K, the darn 4wd gets stuck and I could not go back to 2wd. This can't happen after only 10K miles. I can't go back to the dealer for restitution because it's been 4 years. No, I don't drive it much.

I tried everything I could think of to disengage it from 4wd (?), although I hear there is some voodoo sequence we can initiate that will unlock it temporarily. I also noticed that if I sat with it in neutral and rapid clicked the 4WD button it might change from its constant sequence of the typical midway flashing. My mechanic said he did some diagnostics on it the other day but I don't think he did enough so I will go back to him with much of the information you young geniuses have so generously provided.

I just hope it's not the transfer case again. Thanks, I just wanted to check in since I have been a member for quite a while. I will keep reading.

JoeRuge

I had a similar problem ( I say similar because I expect there are several things that can go wrong that creates this problem). I tried a bunch of different things - even a vacuum pump, which seemed to work.

I heard all kinds of horror stories of not being able to diagnose the exact problem and all kinds of expensive fixes. I poked around for a couple of weeks, living with driving n 4WD until I could scrape up the nerve to start taking things apart.

I finally decided to try the ADD Sensor Switch. Turns out, it was bad and 95% of the problem. Replacing that part fixed the problem. The car still balks a bit, probably from sticky, old grease, but it went in and out of 4WD with very little trouble.

Just a note; last I checked Toyota sells this part of about $75. I found the same switch at Autozone for about $20. They call it a 'back-up Light switch' (part #JA449) It was a gamble because it's not in their catalogues as a Toyota A.D.D Sensor Switch. But it fit and it worked.

pedrojr80

My issue that i have is that i can't switch it to 4wheel drive and most of you guys are lock in 4wheel drive. I got 99 4runner limited with the multi funcion transfer case and today i replace one of the switches in the transfer case and i dint had any luck. Got the switch from advance and like the previous post was mention that the switch is about $22 bucks intead of $70+ at the dealership. I had test the vss valves and both of them got the resistance that they need to have i think is like about 43ohms on each. I try with a vaccum pump to see if the front diff would work and it does i can flip the vacuum lines and i can see when it engage into 4wheel drive so im thinking that it got to be a electrical problem. And yes all the lights are blinking including the orange one in the middle

I did more troubleshooting and find out that im lock into 4wheel drive cause i can turn the front wheels and the front drive shaft turns like when its in 4wheel drive, and i had it in the lift and incan only see the read wheels turning but not the front ones. So far i have replace one of the switches in the transfer case that was bad but no luck i even switch the front diferential switch and nothing.

idlingmike

Any that worked on a 2001/2002 recall if the upper transfer case switches are the same as the lower ones? (27mm). I need to buy a sensor specific socket and I'd love not to order the wrong size


Thanks-
Mike

ManyMods

I finally got my 4Runner with the 4wd locked in over to my mechanic. He spent many hours trying to diagnose the problem. He deduced that the switches were fine and he could make the the front axle actuator function, but not in normal operation. As you can tell, I have no idea what I am talking about.

He got it out of 4WD and told me I had to take it to the Toyota dealer because they had more sophisticated diagnostic equipment -- so I did. After a number of days of varying reports from the service department they announced that after TEN HOURS of time spent diagnosing the problem they thought they had it fixed. I would have been ashamed to admit taking that long to solve the problem if I were Toyota. They replaced the front axle actuator! When I picked up the vehicle I asked them, "Didn't we think that was the problem all along?" They reduced my bill from $1400 to a thousand which I figured out was for 4 hours of time rather than 10 hours.

I did not attempt to engage the 4wd until yesterday and it goes right in and when I disengage it, it goes right out -- no blinking light. However, now the VSC-TRAC activates at the slightest loss of traction. I will call the dealer today because according to my reading that is a relatively simple 'calibration' of the deceleration and yah sensors, so maybe it won't take them 10 hours to make the adjustments. I'll let you know how that goes.

igetfortunota

Hey everyone, I am new to the forum and picked up a bit of a "beater" 2001 3rd gen. Super excited to be here, its my first toyota.

I am in the process of sorting through a few things with the truck which turn out to be really simple but I have the blinking 4WD lights.
Two sensors on actuator have continuity
Reaching top-down tonight to check the sensors at the top of the Tcase

Still need to try to jump the front actuator(and rear for that matter)

My question is: for those that have jumped the actuator, did you check for continuity beforehand? I ask this because I have none when I check SO I want to know if a dead motor(the rusted cap thing) would prevent continuity to the plug. Obviously we know the weak points of the ADD system but I am trying to avoid dropping a tcase if needed.

For reference, the cap is a rusty mess with the little screws so I am thinking once I get the screws off and check, im expecting it to be in poor shape.


Cliffs: Could a crapped actuator motor prevent continuity readings at the actuator plug?


Thanks for any insight! As soon as I have an idea, I am planning on an 01-02 specific thread to my issues to help others

Charchee

I would jump the two actuators first to try and rule them out as problems. I had a mint 01 Runner a few years ago that gave me this trouble several times. On it, I found that if I knew what mode the transfer case was in, by looking for rotation of the front drive shaft, I could crawl under, remove the plug from the front end actuator, and use a battery to jump it back to the position of the T-case. This would get everything back in sync and it would work well for a year or so. I'm not saying that's the issue with yours but it's easy to do and will also let you know that your front actuator is ok.

I'm now fighting with a 2002 with the flashing light. I have done my manual front end actuation and have not seen any result. In fact, when I jump it back to 2WD, as soon as I start the truck, it jumps back to 4WD. I have a different issue. Tested my 4WD button and it didn't give me good readings last night but this morning seems to have good continuity. I'm about to take it for a little ride and see what happens with it rolling. I fell off a tractor at work yesterday and pulled my groin so I'm going to test drive after every step to avoid having to do any extra work. This thing is killing me.

Anybody out there reading this today, I'd sure take some advice that might keep me from doing too much wrenching and twisting. I have a FSM and know how to follow it but if you have any shortcuts or likely causes, please post them. My leg and I thank you in advance!

igetfortunota

Thats super helpful, thank you.

Tonight i was only able to check engagement, front diff is engaged for sure.

I tried to check for continuity with a multimeter but a couple times i heard a noise, other times nothing on the pins...just because its so cramped. Pretty sure its good, but will jump it once i find some small gator clips.

I am now battling getting that rear add actuator motor off.. The three screws that hold it on are just horribly corroded..taking suggestions on that too.

Charchee

I checked my resistance on my TC actuator and it passed the 1-2 test but showed no resistance between either pin and body ground. Rigged me up a relay and used some of the female connectors you find on smaller car speakers to make my probe wires. The terminals fit perfectly and you can place them on two pins next to each other without interference. I set up the relay and wires for 2WD and flipped my switch. The actuator does work. You don't need to mess with the motor until you are sure it doesn't work. Those continuity tests can mislead you to to poor testing conditions over your head and around a bend like that.

I did not solve my problem yesterday. I ended up jumping everything back to 2WD and pulling the 4WD fuse. My ecm is convinced that it is in 4WD and tells all the other components to shift accordingly. I'm leaning toward one of the 4WD position switches above the TC actuator. I cleaned them up real good along with their connectors but couldn't find a test procedure.

igetfortunota

Test procedure meaning checking the switches for continuity? The two that sit right near my tc actuator are good. For the life of me i have no idea how to get to the two on the top that are between the body and housing. I was going to try from the top down but there is a solid floor there.

Great idea with the speaker wire connectors by the way.

Now the manual says apply voltage to 2 and 6 to check, these are the pins you jumped, correct?

Thanks for your inputs on this

Charchee

I believe 2 and 6 are correct for the front actuator. Reverse polarity to work it the other direction.

Do those switches have continuity when in 4WD and not when in 2? Anybody know what section of the FSM that info is in?

igetfortunota

So, it is hard to imagine the actuator it's self when it's working but with the 4WD and the 2WD sensor they have continuity when pressed in. Knowing this, I would imagine that the computer needs to see that the four-wheel-drive switch has been depressed by the rod that is with in the actuator which then sends the signal back to the ECU.

if I am thinking about it correctly, the ECU for the 4WD system probably needs to see that the further one is depressed, otherwise it automatically assumes it is in 2WD.

Charchee

I'll check the continuity on them. I'm not sure why there are two of them or which is which. One may send signal for 4Lo or Center Diff Lock but I don't know. What I really need are resistance specs for them which would tell me that the switch has failed and needs replaced. They are pretty expensive parts to just replace on a guess when they would be so easy to test on a bench. The one I pulled out the other day looked perfect and operated smoothly.

All that being said, I really just want to know exactly how the whole thing works. I have two other trucks to drive and I'm just messing with this one because in enjoy it.

igetfortunota

Both of mine at the actuator were fine as well. I doused them in contact cleaner, worked the plunger part vigorously then reinstalled. Both of the ones near actuator are 4wd position I believe(i typoed my previous post).

How would you attack the ones on the top of the case(4lo and neutral)?

Im lucky as well in that this is a winter beater toy and i dont NEED the vehicle either.

Charchee

I happen to have a parts truck in my carport right now. I pulled the engine with the harness attached and I almost cut two of the plugs on top of the transmission off. I think I can help you out. Give me a little bit and I'll see how I got to them. I did get them disconnected. Unscrewing them may be more difficult.

Charchee

I see em. I'd say do yourself a favor and pull your shifter. They are right underneath it and you should be able to get a wrench on them pretty easy. Mind you my parts truck is a 2000. It does not have push button option. Pretty sure these two sensors are going to be the same on both since they are on the transmission.