2017 tacoma 4x4 failure

I have a 2017 trd sport, recently the 4wd stopped engaging. The light just flashes on the dash. I have pulled the front differential actuator out and cleaned and checked, it is working as it should. I also pulled the transfer case actuator, and did the same. Both are functioning the way they should. Yet my problem persists. I also checked all my wiring and switch. Any help would be great thanks

 

Neutral, foot on brake, engage? Or try engaging then creep the truck forward or backward?

 

Hopefully you go in four-wheel-drive often enough as recommended to keep it from binding up.

I don’t know which one it was, I’ll leave the search up to you, but there are fuse(s) that could be affecting that as well.

also look for any harness or cable damage from rodents. There are so many wires in and underneath the truck that could’ve been affected.

 

How do you know front diff actuator, and transfer case actuator are function as they should? Once a month you suppose to run 4H on the road, up to 62 mph. In 4L find open field with grass, and drive around.

 

I use both frequently, like several times a week. And I tested both out of truck, aswell as I did a resistance test in the truck on both.

 

You ever change out transfer case geal oil, before having problems? Recommended 75w GL-4, but other people will say something else.

 

I changed my transfer case fluid at 40K miles with the expensive Toyota fluid.

https://www.expresstoyotaparts.com/...MIp6iO0ICIjQMVTw2tBh3YgihvEAQYBSABEgI-0_D_BwE

 

$81 a quart. Shhhhheeeeiiiitttttt. did they throw in a TRD can opener?

 

There are cheaper brands of transfer case gear oil. No need go expensive OEM, get Redlne from Amazon, O’Reily’s, if not, someplace local.

 

Very true. I just like to stick with OEM whenever possible. Heck, I even bought my Pro grille from my dealer in 2017.

 

Amsoil Severe Gear.

 

To clarify, there’s no speed limit in 4hi, just a max speed at which you can engage or disengage.

 

O'reilly carries full line of Redline products. Changed my trans fluid today, ended up short about half quart. Ordered MT-90 from O'reilly, picked up from store in an hour.

 

I would replace the actuator’s . They might not be fully engaging .

 

Don't just throw parts at it; find the problem.

I suspect the hubs aren't locking. That can be caused by grease that hardens over time and could be as simple as taking the hubs apart and cleaning off the old grease then re-lube them. Check the simple things 1st.

Transfer case oil should be good for 150,000+ miles. That's not your problem.

Virtually all 4X4 issues are caused by operator error. Guys either don't use 4X4 often enough and internal parts don't get properly lubricated or they use 4X4 where it should not be used and they damage internal parts.

You can get away with very limited use of 4X4 on pavement. But I strongly advise not doing so if at all possible. True 4X4 vehicles like Tacoma are designed to be used in 4x4 only in low traction situations. If used on pavement, or even off road where traction is good, it quickly causes excessive wear to internal components. They rarely catastrophically fail but wear out much sooner than they should.

 

Hubs? 3rd gen doesn’t have ‘locking’ hubs.

OP - if ADD and TC actuators are working, then maybe a position sensor (?) isn’t working. 4WD switch tells actuators to move, ECU not convinced it happened.