Slow, low RPM hill climb. WTF?

It will cut power unless you turn it off.... See this thread (good info here): https://www.tacomaworld.com/threads/3rd-gen-traction-control-modes-explained.530695/

 

Not sure this right. I’ve had traction control engaged while off roading in loose sand and rock before and that’s exactly what it did. Had to turn it off to regain power. That was in a Ford expedition though so not sure it translates.

 

beat me to it.

 

Auto guys - if you manually select a gear does it stick in that gear(like if you stick it in 2 or 3 at a stop it'll start off in 2 or 3) or is it like old school autos where if you put it in '2' it means that 2nd gear is the upper limit but it'll still drop down to first if it feels the need to?(the only automatic vehicle I've ever owned is a Range Rover Classic lol)

Anyway, this sounds an awful lot like when I try to climb a steep hill at a low speed in 2nd when I should've downshifted and it just lugs, whether we're talking about an MT or select-your-own mode in auto if it doesn't still downshift. TRAC does not cut throttle at all in 4Hi(only 2H), VSC will but if you're lugging along at 1000 RPM there's no way VSC could be kicking in, it pays more attention to sudden yaw changes and only intervenes briefly till it's helped you correct a slide(or fucked you over and left you at totally the wrong angle, but still no longer sliding).

On a steep, slippery start in 4Hi(or 4Lo with ATRAC or MTS active) TRAC's braking intervention can feel like it's cutting throttle because the ABS action can be pretty aggressive, but it's actually the brakes pulsing rapidly on some wheels, and once you've gotten going and found some traction it stops. It won't happen all the way up a hill unless it's insanely slick. It's not actually cutting throttle, but the brakes are limiting the wheelspeed for all four wheels which will feel like it's cutting throttle.

 

If you put it in 2 then it can use 1st and 2nd gear. If you put it in 4 the tranny will use 1st, 2nd, 3rd, and 4th.

 

To answer the first part, it's the second thing you said.

Selecting 4th, 3rd, 2nd, etc, limits the top gear to your selection. It still shifts normally until it reaches that gear.

 

Again, maybe in the taco, I can’t say one way or the other cause I haven’t experienced it yet, but in an Expedition it does cut power.

 

Gotcha, well then either it's an MT in the wrong gear or some other weirdness. I can't speak at all to if the auto can maybe get confused and not downshift if TRAC's busy or something? I've experienced what he's talking about a ton in the mountains on dirt or gravel roads if I'm cruising in second, slow down for some potholes on a grade and try to skip the downshift to first. I just always need to downshift to first if it's a significant uphill grade and I slow down to less than ~5-10 mph.

 

Most vehicles do cut throttle, our TRAC system does not if you're in 4H. It will if you're in 2H, though this is easily defeated with a short press on the button that shows a sliding vehicle and says 'OFF'. It will then continue brake intervention but not throttle. A long press defeats the system entirely at speeds below 35(I think, it's some speed in that neighborhood) mph

 

Sounds to me like TC is engaging. That’s when it would happen. Blasting around on loose sand, slow down for a sharp turn, then step on the accelerator to power out and - nothing. RPM’s would die down and vehicle would loose all power. System thinks you’re in a skid. Shut it off and you’re back in business.

 

Right, to add to what I said before VSC will cut throttle in a situation like you said including sudden yaw changes. If it's just a slippery slow climb the traction control system doesn't cut throttle to stop wheelspin, it does its best to transfer power around with the ABS system. VSC will momentarily cut power but I could never see it intervening the entire way up a hill while you're lugging with zero chance of the tail swinging out. VSC will kill the fun, but it won't kill your momentum. It's paying attention to sudden or abrupt changes in yaw(which is physically impossible at 1000 rpm for extended periods).

 

S1 is your friend on steep hills.

I was driving a paved road last weekend climbing up to about 10,000ft and it was more comfortable to lock it in S1 for switchback turns rather than having it lug in 2nd or dance between gears.

 

Honestly, I haven’t noticed any real difference climbing really steep hills in my ‘19 OR. But I do use it as a downhill assist sometimes.

 

Hey Guys,

It was on a gravel road.

TRD Off-Road, automatic. No traction control lights were on (nor were any others), it felt as though the engine needed to change gear, but the RPMs were so slow that it wouldn't (Sorry that's the best description).

2 adults and some gear in the truck, bumper, sliders and decked system, so heavy but not suuuuper heavy.

I wish I tried it in 4 low for a comparison, but either way this felt far from normal.

edit: I also tried S1, same result.

 

Did OP edit his post from "4th" to "4hi"? Pretty sure it was "4th " yesterday.

 

Did your elevation drastically change over the day?

 

be glad it ain't a US spec yaris

to turn off traction control, [to get up one cruddy road I drive...]
you have stop, pump the brakes and the ebrake in a specific
sequence and it is pretty comical....at least trucky (most anyway) have a button.

 

Know when to use 4-low, this was one of those times

 

If you were in fact in first gear, then yeah, you needed 4 low.
4 low is there, for that exact reason.

Only semi related, but we almost always use high range in the fields, and low range in the hills, down at the farm when taking the Ranger out. Much easier on it, if it's not struggling when crawling up steep hills. And, if you need going up, you'll be happy it's already engaged when going down!

 

No, it was 4hi.