a-trac 101 (2 Viewers)

[Karate Chopped]

CDL does not automatically engage in ATRAC model years. Is your truck 2000+?

There is a light for second start on the dash. If you have the power button engaged, the first push of 2nd start disengages Pwr, then push it again to get 2nd start. It does not lock, and resets if you shut off the truck.

Mine is a 2004. I didn't think the first time I used low range it automatically came on, so it might need some investigation.

I also think I might have forgotten to plug the Pwr/2nd start button back in because I swear pushing the PWr button used to make a light on the dash come on.

(Or maybe my dash lighta have stopped?!)

I've had plenty of good opportunity to test out my new driving skills this weekend. Anything hard and rocky seems to be relatively easy to navigate. I did some thick muddy stuff as well but managed to get 4 wheels spinning. A track didn't help me there, but plus side I got to practice all the different winching configurations!

I'm now thinking technical rocky terrain is low and slow, while muddy is a bit faster and straight lines with momentum.

 

[Bisho]

Power button will turn on ECT PWR green light on the dash, if it works. That button does latch and stay on. My light was out for a while and recently decided to come back on.

 

[OEMGUY0720]

Mine is a 2004. I didn't think the first time I used low range it automatically came on, so it might need some investigation.

I also think I might have forgotten to plug the Pwr/2nd start button back in because I swear pushing the PWr button used to make a light on the dash come on.

(Or maybe my dash lighta have stopped?!)

I've had plenty of good opportunity to test out my new driving skills this weekend. Anything hard and rocky seems to be relatively easy to navigate. I did some thick muddy stuff as well but managed to get 4 wheels spinning. A track didn't help me there, but plus side I got to practice all the different winching configurations!

I'm now thinking technical rocky terrain is low and slow, while muddy is a bit faster and straight lines with momentum.

Yes, like loose sand, mud is more often full send style (use momentum to your advantage) combined with good mud tires. and yes low and slow on rocks surfaces. Our LCs/LXs aren’t good for both because of its weight.

 

[Karate Chopped]

Yes, like loose sand, mud is more often full send style (use momentum to your advantage) combined with good mud tires. and yes low and slow on rocks surfaces. Our LCs/LXs aren’t good for both because of its weight.

My heavy footed friend with a Jeep wanted to show off about how he can easily pass through the mud. So after successfully clearing it, decides to turn back around and go again to prove his new Jeep is better than my cruiser.

He promptly get belly stuck in the mud without a winch.

 

[OEMGUY0720]

My heavy footed friend with a Jeep wanted to show off about how he can easily pass through the mud. So after successfully clearing it, decides to turn back around and go again to prove his new Jeep is better than my cruiser.

He promptly get belly stuck in the mud without a winch.

Priceless. Lol

 

[Live to Ski]

kinda related: Per "overlanding/off-roading" youtube gurus (smarter than me), I engage cd as soon as I hit the dirt, even a dirt county road. The rational is that when you need it, you need it fast (tire in side ditch, or...(look up overland lady Alaska lc 100 roll)).

That's not my story and i'm not sticking to it

 

[Escape Artist]

Been trying to figure out puzzling situation with ATRAC. My car is triple locked, and I never see the ATRAC light illuminate when crossing over deeper ditches diagonally, and two tires are in the air at the same time. The lockers just carry the vehicle through the obstacle. However, there’s one particular very steep hill on this trail that is full of loose fist size rocks. Even with all three lockers engaged when the four tires start to spin a little bit at low rpm and low range, the ATRAC light illuminates. I keep asking myself how the system might know that all tires are spinning since they’re all rotating at exactly the same speed? It only does it if all four tires are spinning in an obstacle like that, but it does not illuminate the light on the dash when I am one or two wheels in the air. I’m thinking there’s some algorithm with the steering angle sensor and the ABS sensors and some kind of accelerometer that’s outside the parameters because of the lockers? I’ve been trying to figure this out for a few months and the only time I can replicate is when I can get into a situation where all four tires don’t have traction at low rpm up a 25 degree, hill, or better. Thoughts? I want to go back to that hill and run some more tests, using second gear start, or left foot braking or rear, locker, and center diff lock and then may be front and rear lockers with no center diff lock. Try to see what specific combinations create more or less ATRAC activation.

 

[OEMGUY0720]

Even with all three lockers engaged when the four tires start to spin a little bit at low rpm and low range, the ATRAC light illuminates. I keep asking myself how the system might know that all tires are spinning since they’re all rotating at exactly the same speed? It only does it if all four tires are spinning in an obstacle like that, but it does not illuminate the light on the dash when I am one or two wheels in the air.

The algorithm of any Traction Control computer (Toyota, Land Rover, Nissan, etc) is very basic: ratio of wheel spin of the Passenger Side vs. Driver Side wheels. If both are spinning (L&R wheels), computer sees at as okay both are moving at the same ratio, so no need to pulse-break one side. If one side is spinning more than the other, that’s programming condition #1 and that is to pulse-brake the one that is spinning so the one that is grabbing (stuck) will get the torque hence move the vehicle forward.

If all 4 wheels are spinning, it means all 4 wheels aren’t getting traction (frequently observed in muddy or very loose sand terrain).

When the ATRAC lights up on your dash as the 4 wheels were spinning, did you hear the ABS pulse-braking? If not, that’s the best indicator that ATRAC sees it, but not engaging. My guess is: probably it’s because your axles are lock (diff lock) and it’s sensing in respect to 4L mode and the axles to be 1:1 ratio, basically not enough to engage it.

 

[CactusHopper]

Does this article 100% apply to a 2008-2015 LX or are there nuances with the newer A-TRAC that would conflict with advice/experience in this article?

 

[Mike NXP]

Does this article 100% apply to a 2008-2015 LX or are there nuances with the newer A-TRAC that would conflict with advice/experience in this article?

Same concept, newer hardware.

 

[OEMGUY0720]

Same concept, newer hardware.

Correct on this, software is also new as the the 200 has Multi-terrain Select (MTS) wherein you can control the speed of the wheel for crawling up or down which is still tied with the atrac system.