Engine shutting down while off road

plenty of dealer techs and salespeople perform 'shakedown' runs on un-titled lot vehicles, just sayin'...

 

Odds are nearly every vehicle on the road sees abuse, no matter what. This could be techs and salesmen taking your new car for a “shakedown” drive, bad maintenance, or teenage drivers constant full throttle accelerations on a cold motor. They’re designed to handle the occasional romp, but rare incidents still occur. I’ve learned that I just have to enjoy the truck and stop worrying about everything. If it needs a new motor some day, I’ll gladly fork over the money knowing that there’s more to life than worrying.

 

This could be completely wrong, as I was duplicating in 2WD, not 4WD.


OP. This is absolutely normal, at least it is on my 2021 OR AT. What happened, from my viewing of your video is that you were in gear going forward and the truck stopped forward motion and you rolled backwards as you were in gear. Yes, I know you say you were in neutral, but from the video I can't see you moving the gear shift so fast to put the vehicle in neutral when you should have been in a "Selected" gear with the terrain you were taking on. There was enough torque converter lockup to run the engine backwards - it shut itself off (a stall). When an engine is run backwards its timing gets all goofed up and restarting is difficult. Nothing to worry about, unless you do it thousands of times.

Those with manual transmissions can see this happen more often while 4-wheeling as there is no Torque Converter to slip.

I can replicate this all day long on a steep hill just outside my shop. The dash indications are different if you are in reverse and the vehicle changes to moving forward versus in a forward gear and abruptly changing directions to the rear.

There is mention in another post this simply can't happen as the "Hill Assist" keeps you from rolling backwards - the Hill Assist feature is deactivated while in 4-LO, maybe 4-HI as well. Even in 2WD with Hill Assist I have had the engine stall when rolling backwards with enough distance - this one is a bit scary. Page 318 in my 2021 Owner's manual.

 

Not often but a handful of times it’s happened to me like maybe 3 or 4 times. Happens when you’re in higher gear and you roll back. Recently happened to me when I was going up a big rock and couldn’t get over it so the momentum of me not going up forced me back and engine shut off.

 

People have that issue with the third gens.. I posted mine in other thread which you can find here:

https://www.tacomaworld.com/threads/gen3-issues-with-oiling-steep-incline.827976/#post-29680905

 

I’ve had this happen once when the front end was downslope at a very steep angle. Turn the engine off and if possible roll back to level ground. This was a while ago, and the truck has been fine since.

 

Yeah manual truck does it as well with the clutch disengaged, don't know if it does the same or ignore low oil in 4HI/2HI, but 4LO has a lot of traction control that aggressively ramps down engine output if all the tires spin out.

I haven't tested it by just letting the truck idle out on 40°+ incline, to test if it shuts down on no oil pressure, or if it is 4LO traction system, in conjunction with going beyond 35° over correcting, and potentially thinking you are flipping over that it shut down the engine, or a combination of the above.

Don't know how much of either fail safe modes applies over what, but they do exist.

 

It won’t hold it permanently. It holds for a few seconds and stops.

 

I was stuck on a dune Saturday at a >30º angle, engine running, for about 10 minutes getting winch hooked up & recovering up the hill (I slid to side and had a bit of a drop off behind so backing down was not an option). No issues with engine smoking, sounding bad, warning about oil, and certainly never shut off. I did get a "high transmission temp" warning when done, but a short drive in gentle conditions turned it off fast.