4WD not working but both actuators run?

The 4WD on my 2015 Tacoma will not engage. The green light is flashing when I turn the knob.

The rear actuator has been verified to work (I took the cover off and could see it moved the gear properly)

I can hear the front actuator motor running when the knob is turned as well. So that motor is getting power and doesn't need to be soldered like many others that had this issue.

What else can I look at?

 

Did you check if the Transfer Case and/or the ADD are locking in (jack up the front end and try to spin the front wheels/driveshaft)?

 

I'm having same problem, changed front actuator 3 months ago and problem stopped. About 2 weeks ago light started blinking again so I changed the rear actuator. As soon as I unbolted actuator rod popped out a bit. Now light stays blinking as soon as I start truck. Transfer case is my next guess.

 

Did you time the actuator correctly?

 

I never opened up plastic cover, just triangular plate to remove gear in order to get rod in

 

Still the rod in the transfer case has to match the position the actuator is in when the actuator gear is installed.

 

No, I did not know I had to time the actuator. Truck is currently in 2hi. How do I time that to actuator?

 

With the transfer case in 2H (shift rod fully in) the contacts on the gear should line up with the 2H position.
The first picture shows where it is in 2H on a known good truck, the 2nd shows where the contacts are in each position.
Note there is a couple degrees rotation of spring tension with the actuator bolted up.

 

Looks like both actuators were bad, I measured the sense wire at the 4wd ECU and it was not changing for the transfer actuator. Changed that out then the front still wouldn't lock so I changed the front actuator as well and now wheels lock and I have a solid 4wd light but no actual 4wd.

Solid light, locked front wheels, no 4WD. Thinking the transfer actuator shaft is timed wrong maybe? Is it possible to be timed wrong but the sensor show its ok?

 

When my 4wd stopped working in my 09, it was the front add actuator. It was pretty expensive to get replaced, but the cvs were slinging grease so it was time anyway

 

Both actuators have been replaced and the front locks.

 

I suppose it's possible but unlikely for the 4wd ECU to be satisfied if that were the case due to how the detection switches work.

Does it go into 2wd and the lights go out?

 

Yes the lights go out.

Is it at all possible for the actuator shaft to be too far in when installed? Or install it with the gear not meshing?
Only thing I can think of. It will go into both 4H and 4L but the front wheels don't have power.

I left the shaft in the the transfer case and just installed the actuator by removing the gear through the little triangular access panel on it. Of course replacing said gear on install.

 

It can't be timed wrong and still satisfy the 4wd ECU because the shift shaft in the transfer case has to physically move out far enough to depress the 4wd and Low range detection switches for the lights to go solid.

So the truck does go into mechanical low range?

Did you jack up the front to see if it's the ADD or the Transfer Case that's not engaged?

 

It says it's in mechanical low range, but doesn't function as such.

The front is definitely functioning, with the 4wd switch set to 4H the front wheels are locked.

How would I check if the transfer case is not engaged? Do I need all four wheels off the ground or is there a better way?

 

You should be able to tell if it's in low range or not by driving it.

Just jack up one front wheel with it in 4wd and try to turn it, if your able to turn it see if the front driveshaft is turning with it or not.
If it is then the transfer case is not engaged, if it isn't then the ADD is not locked.

 

Alright I'll check that out tomorrow thanks. The front is definitely locking. Guess the t-case isn't engaging.

I jacked up the front to check the front wheels but didn't think to check the front shaft.

 

So this linked thread has a lot of good pictures of the internals of the tcase. I'm not sure if it will be helpful, but might point you in the right direction if you start digging into the tcase.

https://www.tacomaworld.com/threads...s-for-fj-case-for-manual-transmission.714337/

 

And here is the thread that will likely be the most help.

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

 

Thanks, jacked up the front and the t case shaft would not move with the front wheels.

When the actuator is installed the shaft should be all the way in correct? For 2wd. I believe mine was, looking through the triangular access panel when it is in 2wd it is one spline away from the edge of the shaft.

I took the small gear out that connects to the rack of the actuator and pulled the rack OUT two splines in hope of forcing 4wd at least for the plowing season and now it works, but I'm dubious of the reliability. It will do everything, 2h, 4h,4l. Could the shaft have actually been too far into the case?


P.S Using a big magnet to remove that gear worked perfectly, no messing with pliers and risking damage.