4WD not engaging?

M

mtpktz.

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Well we got our first snow where I needed 4WD and I shifted in 4H to no avail.

The light doesn't come on and it certainly isn't in 4WD. Any help would be greatly appreciated. Thanks guys.
 
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What year and model are you driving? Have you ever had it in 4WD? Are you sure the light works? When you push the selector, do you hear a clicking sound coming from underneath? Need more info please.
 
Sorry, I made the post late last night and forgot the details.

It's a 96 SR5 manual with factory elocker with the 4WD shift.. Yes, I've had it in 4WD, and pretty often. It did this before last winter for a couple of weeks and then out of nowhere 4WD would engage and the light would turn on.

Thanks for any help.
 
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Could be an electronic issue such as the ECU. In other words, it is not getting the correct signal to be on, off, engage, disengage, etc...
 
I am sure there is, but as far as doing it yourself I don't know, ...., I would let the professionals check it. My 02 was acting similar and it was the ECU and actuator that needed replacing.
 
Did you try 4L? Sometimes one works and the other doesn't. If both don't work, problem is likely in the ADD system, especially on a manual. Try this: find the VSV pair (Vacuum Switching Valve) on the driver's fender wall. There are two long hoses coming up from the front diff. Label the front one with tape or something so you remember how it was. Then switch the two long hoses and see if 4WD works. Light will probably stay off. If 4WD engages, problem is in VSV or electric system from TC. If not, problem is in front diff, probably the actuator or in the vacuum system itself--leak, check valve, etc.

System is not that hard to troubleshoot if you understand how it works.
 
TheDurk said:
Did you try 4L? Sometimes one works and the other doesn't. If both don't work, problem is likely in the ADD system, especially on a manual. Try this: find the VSV pair (Vacuum Switching Valve) on the driver's fender wall. There are two long hoses coming up from the front diff. Label the front one with tape or something so you remember how it was. Then switch the two long hoses and see if 4WD works. Light will probably stay off. If 4WD engages, problem is in VSV or electric system from TC. If not, problem is in front diff, probably the actuator or in the vacuum system itself--leak, check valve, etc.

System is not that hard to troubleshoot if you understand how it works.
Click to expand...

I had the same problem, could also be a break in any one of your vacuum lines in and around the VSV or your intake manifold. I ended up replacing all my vacuum lines (very cheap and easy to do, just go to any autoparts store and buy about 15ft of the proper size hose, I can't remember exactly what size it is and just cut and replace one at a time) and whaddya know? It worked.
 
Thanks for the replies guys.

Right now we're getting hammered with snow so I can't try anything right now but I will when it clears up.

Thanks again.
 
2006 4Runner 4WD problem solved

Hey all,

I wanted to share a solution to your 4runner 4WD issues. My 06 4runner 4WD stopped engaging. I checked the fuses, actuator, etc...

The quick fix was below the glove box. There is a black plastic shield or cover. Once you unscrew the small screw in the center of that, you can pop that cover off.

There will be two small computers 1. 4wd computer and 2. Tire pressure computer.

just unhook all three connections for about 5 seconds, and then hook them back up. Test your 4WD..it may work for you..it did for me!
 
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I will definitely give that a try if I have this problem again.

UPDATE: The 4Runner seems to have magically healed itself. The 4WD decided to start working again. This has happened before where it won't work for a week or two, and then work fine.

Any idea what would cause this?
 
ckp said:
Hey all,

I wanted to share a solution to your 4runner 4WD issues. My 06 4runner 4WD stopped engaging. I checked the fuses, actuator, etc...

The quick fix was below the glove box. There is a black plastic shield or cover. Once you unscrew the small screw in the center of that, you can pop that cover off.

There will be two small computers 1. 4wd computer and 2. Tire pressure computer.

just unhook all three connections for about 5 seconds, and then hook them back up. Test your 4WD..it may work for you..it did for me!
Click to expand...

Is the 06 actuator that same as the 3rd gens?


Glad it corrected itself. I wonder if it is just sticky. I would think that a mechanical problem is more likely than a bad ECU. I guess next time it sticks, do what The Durk said to narrow the problem down.
 
2005 4wd not engaging but light goes solid

It appears that my 2005 4runner SE 4wd stopped working. When I go to 4H, the light will blink and then go solid, but the 4wd will not engage. Any suggestions????
 
Isnt his different? he has the manual shifter to engage them not the auto buttons etc. When it does that try rocking the truck back and forth a bit, it WILL lock in and you will gear it or feel it in the second shifter. Mine does that time to time and thats all it is.
 
I am experiencing some of these issues as well. Would the problems cause a C.E.L. to turn on? I notice some people pulling certain codes related to the issue. Although nothing is popping up on my dash.
 
TheDurk said:
Did you try 4L? Sometimes one works and the other doesn't. If both don't work, problem is likely in the ADD system, especially on a manual. Try this: find the VSV pair (Vacuum Switching Valve) on the driver's fender wall. There are two long hoses coming up from the front diff. Label the front one with tape or something so you remember how it was. Then switch the two long hoses and see if 4WD works. Light will probably stay off. If 4WD engages, problem is in VSV or electric system from TC. If not, problem is in front diff, probably the actuator or in the vacuum system itself--leak, check valve, etc.

System is not that hard to troubleshoot if you understand how it works.
Click to expand...

I'm having the same issue as OP. So I changed around the VSV hoses and now the 4x4 is working fine. Even the light is coming on. So now whats my next step? Or is there a next step. It's working... so it seem like the problem is solved.... maybe... Thanks.
 
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spongerx said:
I'm having the same issue as OP. So I changed around the VSV hoses and now the 4x4 is working fine. Even the light is coming on. So now whats my next step? Thanks.
Click to expand...

Next, take a test light to the plugs going to the VSVs. See if the the 12V+ signal is switching sides or not when you go from 2wd to 4wd. If it is, you need a new VSV (or, maybe you can clean and lube the old one, but unlikely). If not, then you have to check the position switches of the TC. You have J-shift, right?

That's a pain, but be happy your diff and actuator are fine.
 
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Free wheelin hubs

Hey i have a 2.8d manual 90 4runner, wanting to swap to freewheeling hub want to know how to do it and how hard is it
 
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