Shifting to 5th and 6th gears in Low 4 (auto)

I have just purchased a 3rd gen Taco with a V6 6A (2020) It has replaced my 09 I4 5M.
I went on my first outing pulling my 17' Bigfoot on logging roads. I found myself crawling up a steep hill and the engine was working really hard so I stopped and put it into low range. It pulled up the hill nicely but I decided to leave it in 4L as I did with my 2.7 but when I got over the hill and the washboard settled down, the transmission wouldn't let me shift into the overdrive gears.. So basically I only have a 4 speed in low range.. I am about to trade this truck in with only 1500 km and get the 6M. Does anyone have any ideas about this? Am I missing something? The truck is really nice to drive on the highway but I love my off road adventures. I mean that's why I bought the TRD Off Road.
Let me know what you think.

 

Are we playing whos the troll ?

 

4lo is for literal crawling. 4hi you can actually get up to decent speed. i dont doubt you was locked out from higher gears.

 

Just switch back to 2 high on the flats.

 

Maybe because 5th and 6th are overdrive gears and its a safety thing? They are the smallest\weakest gears?

Also, you will not be dissapointed with the 6MT.

 

Pretty common to not shift into OD in 4LO, 4Runner does the same thing.

 

ECT power is no joke my friend.

 

WE HAVE A FRIDAY THREAD!~!!!

 

Thanks to everyone for their 2bits worth.. I took the beast out for a bit of a thrashing yesterday.. We have a steep road up to the local ski hill which gains about 2500 feet in 17 Km (10 miles). I boogied up there maintaining +/- 90 Km. (55 MPH?) It was a little soft on the corners and sucked copious amounts of fuel but it felt pretty good. I then found a little off road route that took me up a steep logging road that was muddy and rough with sharp boulders (pretty rough stuff) I also crawled through 3 "deactivation ditches" (ditches dug across the road to stop vehicles going through) so it was interesting to see what the new Taco AT would do.. After a couple of Km's I decided that was enough. I did all of this in 4HI. So, I was pretty impressed with that.. I also got to check the different features the Tranny had to offer. They all work, so then I went down the hill, it was easy to go down using 4 low on the rough and 2 high on the pavement.. I was able to keep the beast less than 80 km (50 mph) going down the steep pavement stuff without the brakes, 2nd gear 5000 RPM at times (the road is really steep in places) but most of the down hill I was able to keep the speed below 80 K in 3rd. ( this is important because it is common to smell nothing but burnt brakes at the bottom of this run when there is lots of traffic.) I then ran home, hooked up the trailer and towed it up the hill too. ( I had to keep the rev's up near peak HP and torque (4-4500 RPM) with the trailer) It was good going up and down so I figured all was good and I can keep this truck with the AT.

Then I drove 50 km without the trailer on regular road and found the transmission was totally confused.. Man, one thing about the MT is it doesn't try to second guess you... Now I don't know what to think .... again.... (sigh) I can only imagine what would happen on a trip across BC when you're going up steep mountain grades one hour then the next you're going across a flat valley, or following along a lakeshore..

 

oh, one other thing... I found the truck was happy to get to 50Km (30 MPH) in low range.. That's all I need in 4 Low..