Another problematic 4WD post

Hi everyone,

I've got a 2005 Tacoma TRD Offroad with 6 speed manual transmission. Since I bought it (2 years ago) I've had issues with the 4wd. At first it was difficult to get into 4HI but eventually it would engage. Now it will not engage at all. The 4wd light just flashes green. I changed the ADD actuator, but it didn't fix it. After looking at the old one, it wasn't in terrible shape(was not jammed and motor spun freely when given current). Today, I jacked up the the car on one side and turned the wheel by hand after engaging 4wd. The transfer case actuator is making noise indicating that the motor is working but the driveshaft going from the transfer case to the front differential is not moving at all when i spin the tires. Am I correct in thinking that this means that it is an issue with the transfer case actuator? The breather hose was on the actuator, but I noticed that it is very cracked where it attaches.

Appreciate any help that you can send my way.

 

https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

Thanks Dm93! I've read a lot of your post already and it's been an invaluable resource.

 

I'm going to try to check voltages at the ECU tonight. I ordered a transfer case actuator off Amazon in case I determine that is the issue. Has anybody had any luck with these aftermarket actuators?

 

They seem to be hit or miss, probably 50/50 wheather it works and lasts.

May be as simple as cleaning the limit switch contacts but checking the voltages is a good place to start.

 

Granted I have a 3rd gen but I just replaced the transfer case.
The actuator rod did not move in and out freely. Something inside the t.c. is binding or broke, preventing it from sliding smoothly.

The t.c. got stuck in 4LO. I had to manually hammer the actuator rod to get it to go to 4HI, then later 2WD.
It should move by hand.

Actuator worked fine.

 

We've seen that a couple times on 2nd gens, seemed to be caused by a cracked low range hub.

If I recall correctly one got stuck in neutral when trying to shift out of low and the other got stuck in low.

https://www.tacomaworld.com/posts/28982639

 

Gives me a place to start looking, once I open it up.
Thanks.

 

It was impressive to see you fix that on the road! James and I barely had time to go for some beer before you got it mobile again!

 

I have an OEM 2nd gen actuator that Id sell you. Unknown condition inside, but I could open it up, clean it and provide pictures.
Also, have a full transfer case.

I have both of these because I swapped my tcase for a manual shift one.

 

@fatfurious2 Thanks! I will definitely send you a DM if I end up needing it

 

So I backprobed the ECU and got these numbers. I did this before work and so I haven't had time to digest what they mean.

https://drive.google.com/file/d/1s0fvBgaASczoXSkSf0F3eUYF-dnRLr1f/view?usp=drive_link

 

Need to see if the Transfer Case is locked in, if it is then we either have a bad 4wd Detection Switch or an issue with it's circuit.

 

I don't think it is locked in because if I lift up one wheel and spin it by hand, the front driveshaft doesn't move. Is that right?

 

You want to see if you can turn the front driveshaft by hand with a front wheel off the ground, if you can't then the Transfer Case is locked in. If you can then it isn't locked in.

 

It's locked

 

Should I order 4wd detection switch? Do these need to be OEM or does anybody know where to get aftermarket ones. I see one on Amazon but don't think it's compatible with 2nd gen. Can the old one be salvaged or is this usually a replacement situation?

 

So we need to check the 4wd Detection Switch circuit, unplug the 4wd switch on the back of the Transfer Case Actuator and jump the pins with a small wire or paperclip (careful not to spread the terminals) then verify 4WD (B22) goes to 0v at the 4wd ECU.

 

So I THINK I did what you said and I still have 11.4v at B22 on the ECU. I say I think because I wasn't sure which side I should jump. I jumped the two pins on the wire. Is this right?

 

If your on the right connector (should be the one with the Red/Blue wire), looks like an awfly big wire your using.