4WD Disengaged when parked

I've used the 4WD system in my 2022 Tundra TRD Pro many times since I took delivery last June. After I drove on the beach yesterday, I experienced an odd malfunction/glitch I didn't really anticipate being mechanically possible.

I drove the truck in 4Hi with the MTS setting in "sand" mode for several miles, then parked, turned the truck off, and spent a few hours on the beach with my family. When restarting the truck, I attempted to put the truck back in the "sand" MTS setting before taking off, as this typically resets itself to either "auto" or off MTS completely after turning the truck off. During this, it said "MTS Unavailable-Transfer case in 2Hi." I confirmed the switch for 4WD was still in 4Hi (it was), and also noted the dash display still indicated the truck was in 4WD, which it was. When I went to accelerate, the back tires dug in without any movement of the front tires at all. I had to manually cycle the truck in/out of 4Hi to 2Hi a time or two before successfully getting it to actually reengage the transfer case in 4Hi, allowing me to drive off.

I guess my question is if anyone else has experienced something similar when their trucks have been shut off, and if so, how the truck is automatically changing the transfer case when the vehicle is off and the switch was left in one position? Seems more than a little odd to me, so was curious if this was a one off issue or what.

 

Is there an axle disconnect of some kind so that the front end is not spinning when in 2wd? I know that is often vacuum operated on other vehicles so maybe it disengages when the engine is off.

 

The f'd up thing about this is that the OP didn't do anything to change it, he just parked. So now the AI takes over and poof! You are stuck Jerry rigging it back to it's senses because it wants you to be in 2wd. Why can't it just return to where it was when you shut the truck down? F'n AI and it's stupid "awareness" making hell out of a simple drive to the beach. I miss the days of a manual shift 4wd for this very reason. You drove there but it won't let you leave! At least you (OP) had the good sense to cycle it and rig it back to it's senses. It really doesn't inspire trust in something being so dependent on electronics to just do nothing either. You didn't ask for 2wd so why is it "thinking" that's what you need? Fuck AI
Glad you made it off the beach OP, and hopefully your truck doesn't keep "thinking" for you and you make it home.

 

How about different senario... run to the store in heavy snow storm in 4WD, come out of store to go back home and it's put itself back in 2WD?!?!

 

If only there was some kind of system where it could be in 4wd all the time, even on dry pavement. They could call it Full-Time 4wd. I wonder if anyone has ever thought of that before?

 

nearly every vehicle i've encountered where the mode is selected digitally does this.
I actually talked to folks at Toyota about it; they explained to me that this decision was made because operators tend to forget that they're in 4WD and bind gears/blow transmissions.

 

So make it 2wd capable, like a 1st and 2nd gen Sequoia was for the last 22 years.

 

Very odd. Thanks all for your input. I'll play around and see if I can reproduce it, but I had not seen it do that before any of the previous times I'd parked it on the sand/snow in 4Hi.

 

I just had a very similar experience on the beach except I never even shut my truck off. I switched it to 4hi before entering the beach but ended up getting stuck because it never actually engaged. The indicator on the dash showed 4hi but only the back wheels were spinning. I had to shut my truck completely off and turn it back on to get the front wheels to engage.

 

@chaztizer

If the lever is in 4Hi and it disengaged you have an issue and it needs to be diagnosed.
Whether or not it is the actuator module needs to be determined.
if its intermittent this could be difficult to replicate.

 

I was unable to ever replicate this issue, but definitely had the lever in 4Hi when it disengaged. Very much agreed it represents an issue, and hopefully Toyota is able to get to the bottom of it.

I actually had this truck replaced under a lemon law case by Toyota yesterday for a different issue, so at this point it belongs to Toyota again. I’m convinced the truck was just built on a Friday afternoon.