teleman37

Hi, Newbie here. I have a 2000 4runner SR5 with a 5spd manual. My problem is I can't get the 4wd to engage. I have done a search and read all of the articles but I can't seem to figure this out. I took the vehicle to the dealership and told them to diagnose the problem. they said it was a transfer case switch/sensor part number 84222-35110. They didn't have one on hand and I didn't want to pay them to fix it, just diagnose. I ordered the part online and replaced it. Still no 4wd.

The front driveline locks up when placed in 4Hi but the front wheels will not turn when jacked up off the ground. I don't get the 4wd indicator light on the dash either. I'm assuming my ADD is working correctly because the front driveline locks up when placed in 4HI and turns freely when put back into 2HI?

This is my daughters vehicle and she needs 4wd. More snow headed this way this weekend too. Any help would be greatly appreciated.

teleman37

UPDATE: I switched the hoses on the VSV and now the 4wd is engaged. Do I have a bad VSV?

Charchee

First of all, I don't think any manuals had this but does your 4WD engage with a button on the side of the stick or by pulling it back? Two completely different setups. I would bet you pull it back. So this is how it works.
Pull the stick back.
Transfer case engages
ECU reads signal from the 4WD position sensor/switch in the TC and is informed that the case it turning.
ECU sends signal to VSV to lock in the front end.
Vacuum is applied to the actuator and the front end locks.
Another similar switch/sensor in the front diff sends signal back to ECU.
Only after this will the 4WD indicator light in the dash light up.
Shift to 4WD is complete.

If the transfer case sensor doesn't send it's signal, the front end will not engage and that's the end of the line. You're case will be turning along with the front diff but the axles will not turn.
If the signal does come back from the case as good and the ecu sends its signal to the VSV, and it fails to work. Same situation
If the ecu sends signal to vsv and it applies its vacuum correctly and the actuator on the diff fails. Same situation
If ecu signals, vsv sends vacuum, actuator works properly, and the sensor in the diff fails to verify the shift. You are in 4WD and don't know it as far as the dash light indication.

Now on the way out of 4WD, same rules and same players.
If you push the stick forward and the TC sensor doesn't inform the ecu that it is unlocked, then nothing downstream in the chain of communication occurs and your front end stays locked.
I think you get the point. All of the situations in reverse. Basically, every component has to signal the ecu that it has done it's thing before the next one can get permission to do it's thing.

When you swapped the vacuum lines, you put the ADD actuator in reverse. I wouldn't count on it being bad yet. You may have just worked it out of a bind. Did you swap them right back before you tested it? If you did, and the computer was still sending signal to shift, it would just jump back into 4WD and you would be in good shape. Also, testing it jacked up can give you some weird results. Sometimes it takes moving forward/backwards and turning the wheel to get it to lock. Normally not but sometimes and actually you need to roll it just a hair 99% of the time. Being jacked up can give you a false indication that something is messed up. Best way to test it is on loose gravel.

If you haven't already, put your vacuum lines back on correctly and try it out on something loose. I bet it's working again. Most of my experience troubleshooting these is on 01-02 models which don't have a VSV but have an electronic actuator in the front end. I have had an issue with mine not going into 4WD or not coming out three times on two different trucks and can normally solve it by applying voltage to the actuator in a way that would reverse it. In these cases I have plugged the connector back into the actuator and the computer would try again with success to complete the shift and problem solved.

I can get you through this issue for sure but since you aren't online right now, I just thought I'd throw you out a little info to chew on. Get back with me if you still don't have it figured out. Don't want her driving in the snow without 4WD over something little.

One more question, did the dealership tell you that the bad sensor was in the transfer case or front diff and where did you install it? There are a couple of them side by side on the transfer case and one in the front diff. The one in the front is normally the culprit but it could be one on the case. Just want to make sure you replaced the correct one.

teleman37

Wow! Thanks for all the time and effort you put into the reply. I have not switched the hoses back yet. I quit for the night. The dealership said it was the switch/sensor on the passenger side of the transfer case. I replaced it but still no go on the 4wd until I switched the hoses.

TheDurk

I have the same setup you do on a '99. You have ruled out any issues with the actuator and with the TC. The issue is between the VSV and the sending switch. First, actually check that you HAVE vacuum on one hose, and that it does not switch sides. If no vacuum, check the check valve, and all hose connections, hose condition, and the integrity of the reservoir under the fender.

To test the VSV, use a test light or meter to see if the 12V+ trigger signal is switching sides when you go from 2wd to 4wd. If it does, then VSV is the issue. If it does not, we have to move on to the 4wd relay in the passenger footwell.

Did you keep your old switch? Is it actually bad? This would be very good to know.

With all due respect to Charchee above, there are some real differences between the J-shift/vacuum system and the push-button/electronic actuator. First off, there is no ECU, just a simple relay. Second, the only thing the ADD switch does is turn on the light, so it is not the cause of most problems, other than 4wd working but no light.

Charchee

I think TheDurk is spot on. First make sure your vacuum lines are intact and not cracked around any of the points where they attach. I kind of feel like the issue may have been with the 4WD position switch in the transfer case though. They have been known to act up from time and then work for a year or more before they do it again. I bet the VSV was not triggered to switch on that particular shift.

Yea, my info wasn't perfect for his setup. I have torn apart a system like this in my parts rig but have never had to physically repair one of them. I was just trying to give him a generic description of the flow of things. Sounded like he needed some hints pretty quickly. Not too far off other than the ecu/relay discrepancy. I sure do like you guy's setups better than the electronically actuated TC's like mine. I sure did scratch my head when I completely tore down my parts truck and never found the 4WD ECU. I am enlightened.

Hey Durk, he said that the switch he replaced was on the passenger's side of the case. Is that where the 4WD position switch is located on your setup? On mine, I believe that switch is on the driver's side. Mine is electronically actuated but I have the same three switches in mine in the same locations. I have had issues with my front end not shifting on both of my electronically actuated 4Runners and both times found a bad switch on the driver's side which I replaced and fixed the problem.

Teleman, you can easily test the switch you took out with a multimeter continuity test. Don't just press in the ball at the end one time and check for continuity. Slowly push it in and then let it come back out while listening for the tone as well. Do this a bunch of times. If it's anything like mine, they will pass or fail on the first try but after working it a bunch of times, you may see that it works 90% of the time. In my book, that is a fail because you can bet that the one time you really need it bad, that will be the one in ten times that it fails.

TheDurk

I was trying to remember. Unfortunately, you can't figure the answer to that from the EPD, the EWD, or the FSM, and it has been 13 years since a mouse ate my 4wd position switch wire. I think you may be right. I'd have to go out and feel for the repair I did. That's one reason I asked to test the switch he replaced. If it turned out to be good, I was going to say it's probably the other one. We just have two, 4wd on one side and L4 on the other. The L4 just does something to the engine and permits the rear locker; it's the 4wd that triggers the ADD.I can't believe a dealer tech would say the L4 is the problem. Well, I can, but it's disappointing.

teleman37

I did a continuity test on the old switch....several times. I'm positive that the old switch is bad. I tried it like ten times...no continuity. Tested the new one before installing it and it had continuity. That switch is located on the passenger side on top of the transfer case. I have to return to work this weekend so I guess she will be driving my wifes trusty Subaru till I can get time to work on it again.

Charchee

My notes indicate that it is the forward of the two sensors on the driver's side that signals the front end lock. The two on the drivers side are easy to take out and check. Probably a 20 minute job. Maybe 10 since you already know the socket size and are familiar with the electrical connector removal. Like Durk said, there is no indication in the literature of this but I feel pretty dang confident in my notes on this. I was also under the impression that the one on the passenger side (which does seem to be bad) is for the 4LO indicator. Did they test the other two?

Durk, correct me if I'm wrong, but If he were to do a shift to 4WD to test it and the front not lock in, couldn't he do his vacuum line swap trick, lock in the front end, and then disconnect the VSV, allowing her to drive it with the front locked in full time until he had time to finish the repair?

I wouldn't recommend doing this unless it was absolutely necessary but the older Limiteds and all of the 01-02s are designed to run on dry pavement with the center diff unlocked. I don't see a real difference with this scenario.

TheDurk

Sure. I would not recommend it long-term as you have additional wear on the front d/s bearings and diff gears but no issue short-term. If the TC is in 2wd there is no binding in the drive train which would be the bigger worry.

There are only two switches on the J-shift TC, like I said. 4wd and 4L, one on each side, both up top. I'll check tomorrow which is the 4wd that controls the ADD. You can also tell by wire color, now that I think about it. If OP replaced the one with a BLUE wire, that's the 4wd switch. If it was BLUE w/RED stripe, that's the wrong one (4L).

Charchee

Only two huh? Man Durk, you and I have walked a hundred folks through these issues and I swear there's something new to learn every time. I see no reason why in the world a J-Shift with no actuator would have three switches but there is one in my carport with three of them. 2000 SR5 Auto. I mean how many different configurations did they make? What the hell is that third switch. The third switch in the electronic ones that I'm familiar with is for the center diff lock/unlock best I can tell. Could it be a neutral position indicator.

I don't know. Just thought you'd get a kick out of that.

teleman37

The SR5 in my year only have 2 seniors, one on the driver side and one on the passenger side. I removed the crossmember under the transfer case and used a jack to lower it down just enough to get my gear wrench on the sensor. I could only see 2 sensors.

TheDurk

Huh?. You got me. I do not have EWDs for 2000 and I just use my '99 as they are always identical to 1999. (Canadian 1999s because they have DRLs.) I'd love to see that EWD.to see how it changes with that extra switch..

Charchee

I don't think the FSM for the 01-02 models ever mention that switch although I know there is a switch somewhere that tells the computer that the center diff is locked. I just figure that it's the one furthest back on the transfer case since I know what the other two are for. I just can't figure what the third one is on the transfer case I pulled form that 2000 model with J-Shifter, no actuator and no center diff lock/unlock option.

teleman37

Well, I have changed the VSV out with a known working one and still no 4wd. When you engage the 4wd lever should you hear a clicking noise from the relay in the passenger kick panel? There is no noise when I engage the lever. On a side note, I did change the water pump and timing belt while I had it in the garage. One less thing to worry about lol

Charchee

I can't speak to the sound of the relay since mine doesn't use one but check for electrical signal at the vsv. You could then check for the trigger signal at the relay. I'm thinking pull the connector off the 4wd position switch on the transfer case (driver's side) and short the two pins in the connector. It should send signal to the relay to close and signal the vsv to switch. If it does, replace the position switch. I think they told you to replace the wrong switch to begin with.

TheDurk

Did you do the test I suggested in Post #5 above before swapping the VSV? Swapping parts without a fail indication makes no sense to me. Plus, I can't suggest what to do next without you having done that.

The relay makes no audible noise when you engage 4wd.

Charchee

Follow Durk's instruction first. Then short (using a piece of wire connected to each leg of the connector) the 4WD position switch connector (driver's side front switch in TC) and then check the vsv again as Durk instructed. I bet you'll see that it has switched.

When the 4WD position switch has no continuity, the relay signals the vsv to apply vacuum to one side of the actuator. When it has continuity it signals it to apply vacuum to the other side. That's why you could get it to shift the actuator by swapping the lines. I'm calling final answer on this one. I bet that switch is bad.

teleman37

Durk, I have a friend who has a 4runner and I used his VSS switch to see if that might be the problem. His 4wd works so we could rule the VSS out as the problem. Charchee, there are only two switches on my transfer case, one on the left and one on the right. The dealership said the one on the passenger side was bad. I tested it and it was. I have not tried the one on the drivers side.

TheDurk

Do you still have the old switch? If you do, can you give me the wire colors?

Well;;, I'd still prefer you tested with a light. Especially because going forward, you will have to do testing at the 4wd relay in the passenger footwell. It's bolted to the firewall, a few inches off the ground. Unbolt, and get it to where you can play with it.