4WD issues. Looking for some insight!

Hello all!

I am having quite the headache regarding my 2011 SR5 4wd system and I am hoping someone could help!

How this all started was I went to start my 4runner one day and upon startup when all the other dash lights came on for a second or two like normal, I noticed my 4wd indication lights did not. So, I tried to activate my 4wd and had zero luck, no lights came on my dash, nothing engaged at all, it was very odd. I have no check engine lights or had any other issues with my 4wd until that day. So I took it to Toyota for a diagnostic and this is what I was told. "4wd inop verified that transfer case does engage for 4wd function, but front differential/axle does not. Model has TSB 0066-12 stating that automatic disconnecting differential shift actuator is inoperative."

I then took my 4Runner to a friends house who had the same issue with his Tacoma and he said its likely that the actuator motor/internals are corroded, apparently that can be common. So we did some investigating by removing the actuator and looked inside and it looked brand new, absolutely perfect it looked. We also supplied power to the actuator motor with a 9.6v battery to confirm that the motor would work, it worked flawlessly. We then put everything back together and tried engaging 4wd with no luck. While my 4wd shift lever was in 4wd still we took the actuator back off, we moved the collar into 4wd in the diff ourselves and then placed the actuator back on. Upon start up of the vehicle my 4wd indication lights actually showed up but were flashing. I tried to get the 4runner to engage into 4wd with no luck. I then put the 4wd lever into 2H and tried to go back to 4H with no luck, no dash lights or anything.

It seems that my actuator is perfectly fine and works as it should when we tested it, so Im very lost with this issue. All the fuses are good as well. Toyota quoted me $1100 to replace what seems to be a perfectly fine actuator. Did they misdiagnose or are we missing something? I am hoping someone on the forums could point me in the right direction. I just cant justify $1100 bucks for something that may be just fine and will be charged for no reason. Thank you all for reading.

 

Bench testing isn’t always accurate because there’s no load on the component. It moves fine when it’s not trying to move anything, that doesn’t necessarily mean it will move fine while it is trying to move something. However, if it works on the bench but it doesn’t in the car I’d be tracking down a wiring diagram and looking into the switch/wiring. Luckily these are pretty stupid vehicles electronically so it should be a simple setup with 1 wire for 1 function. That makes it a lot easier to diagnose than if it was all through a bus.

 

Im just stumped as to why the dash light wont come on when the vehicle is started. It may be a wiring issue I am not sure.

 

Is the 4WD ECU, sending a receiving signals? Get a wiring diagram, figure out how the system works, and start checking things.

 

My 4wd lights don't come on when the ignition is first cycled. I think you're misremembering things. My Tacoma didn't, either. It's only warning lights that illuminate.

 

dang, I swore they did. Still stumped on what going on. I tried to activate the 4wd again, so the actuator motor was under load and nothing.

 

Squirrels?

 

I highly doubt it. Not many where I live. Im going to take a look at the transfer case and see if the problem presents itself.