Crawl Control Question - Lurching at Lowest Speed Setting

Hey guys! I finally installed my sliders and skids, and took my 2019 DCSB OR Automatic out yesterday to put the truck through its paces. I wanted to test out all of the various features of the 4WD system, including Crawl Control.



As many others have noticed, the Crawl Control system on the slowest setting lurches a lot. The system abruptly applies the brakes then throttle while "crawling." As you adjust to a slightly faster setting, the speed smooths out. I was using the CC on some fairly aggressive terrain, both uphill and downhill. Is the lurching on the slowest setting normal?

Under what scenario would you use the slowest speed setting of Crawl Control? Does the slowest setting perform better with extremely aggressive terrain?

Here is the terrain I was wheelin' on for reference. It was at least a 30 degree incline/decline in some areas of the trail.



In before:

• "Crawl Control is my right foot..."
• "Shoulda' got the manual trans..."
• "Just adjust the speed setting faster..."
• "Crawl Control is a gimmick..."

 

I also noticed the same when I decided to try out the crawl control while out wheeling. Interested to hear what people have to say

 

Here is a little more intel on the topic. There are not many Crawl Control demos that illustrate the lurching. But I stole this from another thread. At 0:24 you can see the operator engage Crawl Control and the truck begins lurching forward. At the steepest part of the obstacle (0:48), you can see the truck begin to smooth out and the lurching ceases. I'm not sure what speed setting the Crawl Control is in the video.

https://www.youtube.com/watch?v=XJkJ3bwoaCI&feature=youtu.be

So maybe the terrain just needs to be more aggressive for the low setting of Crawl Control to function properly?

 

I'm in for the replies as I've not been off - roading in mine yet and haven't had the opportunity to use the CC. However I noticed the terrain looks very familiar. Where are these pics taken? I live north of Austin close to Fort Worth, but we travel down that way quite a bit to mountain bike...It would be cool to have a place to play with the Taco as well!!

 

It's on Lake Travis near Lago Vista. I grew up 4 wheeling that trail, so it's my benchmark!

 

I’m guessing the speed range for the lowest crawl control is slow enough that if the terrain isn’t restrictive the brakes must be applied in order to keep it within the specified range you have it set to. That results in the on/off lurching feel that goes away when you select a higher speed setting.

 

Your truck is outrunning craw control

Speed up cc or rougher/steeper terrain

 

Is it on public land...? I probably know the answer to this already...this is Texas...(sigh!)

 

Crawl Control is just a super 4Lo

https://www.youtube.com/watch?v=19BNRvuNLWE

 

It's always been lurchy. Can see older land cruisers do the same .Wish they could smooth it out and also raise the top speed value

 

All the above

 

I'm assuming at that level of crawl control its restricting speed. For use as in going down grade and you don't want to have any speed going. But I'm sure someone with it can elaborate more

I have an MT

 

Nossir. Private land.

 

Here is another angle. You can see it begin to smooth out at the 0:50 mark.

https://www.youtube.com/watch?v=AFqfVc19PWM

 

...And here is another example. At 0:45 you can see the driver engage Crawl Control in the slowest setting. I don't know if he actually left the CC on the slowest setting the entire time. Because the truck is in the snow, there is no "lurching" like in the other videos.

https://www.youtube.com/watch?v=bAgTHP0PMF4

It seems like you should only use the slowest setting when the terrain is extremely aggressive, or the traction is really low, to avoid the lurching.

 

Here is another good video. As the truck gets into the most aggressive portion of the obstacle, it smooths out slightly. I think the lurching may just be a shortcoming of the system.

https://www.youtube.com/watch?v=pWgVxrwXXeA

 

The lowest setting is like that for very slow crawl situations. It essentially makes a fake 4.56/4.88 gear ratio. It's the ABS going bananas because the truck idles higher than you're going to give you power. Slowing the rolling idle speed to like maybe 1/2 mph vs 3. I've used it on trickier situations, best use rock gardens/mogul type. Each wheel kinda crawls. I find it works better at like the second or third notch when the abs isn't fighting the idle speed. Haven't used it since because honestly the mts set to the terrain you're on, 4lo with the rear locked, the front works like a simulated LSD adjusting with the spin and grip to each wheel. Works well surprisingly. With the auto put it in S-2, ECT on. Probs best setup to wheel on these with out having a front locker.
Also there's load on the system while going uphill hence no jerky braking

 

Slowest speed crawl is for extremely steep uphills and down. It is smooth and controlled in those conditions.

 

Agreed! I was amazed at the capability of the truck using MTS. It’s just so badass.

With the Crawl Control low speed setting, I’m really just trying to answer the question - When does Toyota recommend I use Crawl Control at the lowest speed setting?

 

Checked the Owner’s Manual too. Toyota recommends using the slowest setting only on downhill terrain. Dunno if that’s exclusive. The chart does say “typical terrains and the recommended speed modes.”