Four wheel not engaging

Greetings and salutations all!
I have owned my 2011 Tacoma Sport for 5 years, just hit 105k today.

About today, I needed to use my 4x4 on a snow packed hill. I turned the switch to engage it, thr light came one-not flashing but a solid green- and the truck did not engage into four wheel drive. Before I see a technician, any advise you all could give would be greatly appreciated.
I can hear the actuator working, but it fails to engage.
Please help!

 

There are 2 actuators.
One on the Transfer Case and one on the front Differential.

First, see if you can get in to 4LO. (Even if the 4WD isn’t working)
If so, it’s probably not the Transfer Case Actuator.


To diagnose it- (Easier) You’ll need to have jack stands.
Jack the truck up with all 4 wheels off the ground.
Put the truck in Neutral and spin the front tires.
If the front driveshaft spins while turning the front wheels, the front actuator has engaged the front ADD. (Good news) It’s probably not the ADD actuator.

There are limit switches for both Transfer case and ADD.
They could be bad, more often than not it’s the internal components of the actuator(s). It’s usually not the limit switches.

If you really want to figure it out, see the link here
https://www.tacomaworld.com/threads/4wd-system-help-and-information.696298/

 

TnShooter, thank you for this information
I have access to a warm garage tomorrow morning.
I'll update if I'm able.