2012 Tundra, Tow/Haul Mode, Cruise control

[RUSTYDAWG]

I have noticed that while towing the cruise control will shut down while climbing on rolling hills. Few percent grades or so. And certainly will not activate while climbing a grade of say 5%+. I haven't tried with tow haul mode deactivated.

Is this normal? As in a safety thing?

[StevJ]

Shuts down? So the CRUISE light on the dash goes out? That's odd.

Steve

[RUSTYDAWG]

The cruise control light stays on, but the cruise control deactivates. Its more like a gradual roll back.

[RRzxter]

I've done the opposite:
Never used CC in tow/haul mode.
I've used CC while driving through mountains and it doesn't kick off.
It will downshift like crazy to maintain speed up/down the grade, but stays on.
Going downhill, I actually had to turn it off and ride the brake.

[eclipse3g]

Most cruise controls will shut down if the speed drops by a certain amount, not sure what Toyota's setting is by my older Chevy PU this would happen to going up long grades when heavily loaded.

[Rock_Warrior]

My 2012 tundra does the same thing. When towing my trailer up a big hill and it downshifts to 3rd gear the cruise is deactivated. Light stays on but cruise goes off.

[RUSTYDAWG]

@rockwarrior
Have you spoken with anyone at Toyota about it? I am wondering if its an adjustable threshold.
It really sucks because mine will shut down on as little as a 2-3% grade. I am pulling ~7000Klbs.

[RRzxter]

When you guys are saying that it deactivates, you're talking about while in tow/haul mode, correct?

[Rock_Warrior]

I'm also towing around 7,000#. Like I said mine only does it when it has to kick all the way to 3rd gear. Downshifts to 4th and works fine. Yes I have Tow/Haul Mode on. I called 2 different dealers today just kind of asking around and one place said it was normal and the other dealer where I actually bought the truck called me back but I missed the call.

[RRzxter]

I just wanted to make sure I wasn't giving false info.
Like I said, mine stayed on and was downshifting till it sounded like it was at redline (it wasn't, just sounded like it).
I actually had to turn the CC off.
But, I wasn't towing anything and wasn't in tow/haul mode.

[sheltonlp]

Personally I do not like the idea of CC while towing. I want to feel my load so to speak...I adjust my speed according to my terrain--faster if going downhill, slower if going up. This helps MPG a little and makes it so my truck is not fighting to stay at a set speed. If someone is behind me or if I'm towing with other friends towing their rigs I adjust my driving a little but I still do not use CC.

[11Tundra]

If one watches the upper-dash INST MPG display, it's certainly obvious why it's better to not use cruise control when climbing or going into headwinds while towing. Under these conditions, the cruise control compensates immediately and radically, with no regard to load (or fuel consumption). Under normal, low-load conditions, the engine is capable of quickly dealing with speed changes, so this M.O. works great. Under heavy-load, towing conditions, however, the engine is not capable of responding quickly enough and the cruise control could care less. It forces the engine to try to regain speed immediately, at all costs--to include application of full throttle and radical downshifts by the transmission. Pretty much a lose-lose situation resulting in increased fuel consumption and increased wear & tear to the engine and transmission.

[ct03911]

I agree not using CC is the better way to run rolling hills. On the flat, sure, I've done that on a long haul.

[Rock_Warrior]

Long story short is the cruise shouldn't kick off.

[hnd2hnd]

If you have it...have you tried using the manual shift down to third and see if you can engage cruise.. I haven't tried CC while towing yet.. I have a 2010 Crewmax 4x4 5.7L.