YotaTech Forums - 1999 4Runner Limited stuck in “AWD”

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1999 4Runner Limited stuck in “AWD”

Hey guys, new to this forum but have been on many others for years. I recently purchased a 1999 Limited 4x4 with rear E locker. Since purchasing I have realized the 4Runner is stuck on 4WD with the center diff open “AWD”. The Dash light is flashing constant with no change apon moving the transfercase shifter or button on side of shifter.

I have searched multiple forums including this one, high and low trying to diag and test as much as possible before creating a thread. I have tested all vacuum lines, Voltage at VSV’s, replaced front diff switch, tested the 2 switches easiest to get at located on the transfer case actuator, and have also jumpered the switches located at the top of the transfercase with no result of any kind. I’m leaning toward the transfercase actuator motor/gears being the failure.

With that being said I can’t seam to source that actuator any where except the dealer ( for nearly 1000$ ). Does anyone know if I can take a transfer case from an SR5 that doesn’t utilize the AWD function and this actuator and replace it? If so does a module need to be swapped as well?

Any input would be amazing, sugfestions, options, things I may have missed.

Thanks for your time,

-Blake

Actual actuator failure seems to be low for these symptoms. If you follow thru this thread:

https://www.yotatech.com/forums/f2/4...er-ltd-131201/

(apologies for it being a dozen+ pages) You'll find that most of the time the dealer recommends replacing the actuator because there isn't a step-by-step repair and diagnosis for this symptom, i.e. blinking 4wd lights and failure to shift appropriately. From what I have gathered (and others before me @99SC4Runner, @TheDurk, etc) the position switches (or sensors more appropriately) are the number 1 failure point. There is 1 on the front diff, 4 on the transfer case, and 1 on the rear e-locker. You need to take each out, clean with contact cleaner, and test with a meter for continuity thru the full range with zero dead spots. Next in line is the limit switch paths in the actuator. Post #69 in my build thread has some pictures (https://www.yotatech.com/forums/f200...11/index2.html) Finally is the actuator itself. You are talking about a nearly 20 year old electrical component so it's possible it could fail, but unlikely.

When I was at my wits end with my issue, I checked with some eBay sellers for a whole used transfer case. They would honor the actuator's functionality under there warranties because the actuator is an integral component even tho they typical do not warranty electrical parts.

Quote:

Originally Posted by fierohink (Post 52396204)

awesome, thank you! I will continue to test switches and verify. As for the 4 located on the transfer case... is it just the 4 on the driver side? Two at the actuator easiest to get at and then the 2 up above them closer to the drivetrain tunnel? I read somewhere on here that there is another switch/sensor mounted on the top of the tcase they were only able to get to by lowering the trans/tcase?

Quote:

Originally Posted by fierohink (Post 52396204)

Next in line is the limit switch paths in the actuator. Post #69 in my build thread has some pictures (https://www.yotatech.com/forums/f200...11/index2.html) Finally is the actuator itself. You are talking about a nearly 20 year old electrical component so it's possible it could fail .

Were you able to just clean the contacts, remove the old hardened grease and get your original actuator to function? I pull the 3 10mm bolts out yesterday and removed the cover exposing the gear and contacts. I also found the horribly dried out yellow grease. When I went to re assemble it was tough getting the shaft to align and slide back into place. The splines on the end of the shaft connected to the contact gear didn’t want to seat. I noticed the female splined part located in the actuator was loose to move free side to side and this got me wondering if there was damage or a break inside. Do you know if that female spline is supposed to be loosely moving like that? To the point of having to align it to be able to slide the shaft on contact gear up into place.

When I took the 3 10mm bolts off for the cover, I didn't take anything else out, just the cover with the 3 brass contact pins. Then with some really fine emery cloth I shined up the contact traces. If you are too aggressive you'll wear thru the tracks and destroy any chance you had of salvaging the actuator. I can't say I played around with any other components inside once I had the cover off because I felt the tarnish was a pretty good indicator of my troubles

I’m having the same issue I changed my transfer case all the sensors on the tC and front differential and what I noticed is that I’m only getting voltage to the blue vsv so the 4wd vsv is always getting vacuum i also changed the 4wd vsv anyone can help me with this ?