Does ATRAC/ABS work in reverse?

[4boer2]

When I say reverse I mean when the gear selector is in "R."

Here is the story: I was backing down the boat launch ramp with my foot on the brake, gently rolling down. There was a dead fish on the ramp, but instead of just rolling over it, it got caught under my front right tire. I dragged the fish for about 20 feet before I stopped to launch the boat. The front right tire did not turn once the fish was under it, it just skidded the rest of the way down. Nothing beeped and no "Toyota Dubstep" (that's what I call the sound that the abs/dac/atrac makes). The other three wheels were spinning, center diff unlocked, and in 4HI (normal for a Limited).

Point of the story: Should the system have been working or does it disengage when in reverse?

 

[4boer2]

 

[settytb]

I'm not sure if ABS works under a certain mph. If you are inching down the ramp I don't think it would do anything. I've gone backwards quickly and hit the brakes in snow and I think it came on...trying to remember...(hasn't snowed in a while). But the hill control only works in drive or lower gears i know in neutral and reverse it doesn't. I know that much for sure. But again i think if you were just going really slowly abs doesn't do anything. Just my 2 cents.


BTW that fish is kinda gross...smeared all over the ramp. Yuck.

 

[4boer2]

It smelled worse than it even looks. Thanks for your opinion. I didn't have a problem with it not kicking in, it would just be nice to know it it will/ should or not during the snowy months.

Edit: yes, DAC and HAC need to be in a forward gear in order to work. DAC also need to be in 4LO.

 

[medicrn]

Think I understand your question but I am not a mechanic type guy, but i do know how to drive to one

first, having been stuck in the snow in NJ the atrac does work in reverse and i think abs does as well but i can not recall if abs beeps ever.

now here's where i say sorry and i am new to the forum, but didn't Atrac in your situation do what it is supposed to do without center locked?
my limited understanding is when one wheel slips it stops slipping and transfers torque to other wheels.
I think that 4HI is normal because it is a V8 not because of the trim being the limited model.

 

[4boer2]

I think that 4HI is normal because it is a V8 not because of the trim being the limited model.

Interesting, I never though about it that way before.

For clarification: In my case, A-Trac should not have operated because I was not in 4LO. The only system that beeps at you is VSC, which would have been active because the center diff was unlocked, and that probably should not have engaged because I was not going sideways. So that leaves us with a simplified question: Does ABS and child systems function while in reverse?

Thank you guys for your answers and sorry if anyone is confused.

P.S. If anyone needs an excuse to "test," here it is :biggrin2:

 

[JB.]

ABS and DAC both work in reverse on my '05.

I don't specifically recall about atrac in reverse, but I'd be willing to risk a large sum on a bet that it would.

 

[medicrn]

Interesting, I never though about it that way before.

For clarification: In my case, A-Trac should not have operated because I was not in 4LO. The only system that beeps at you is VSC, which would have been active because the center diff was unlocked, and that probably should not have engaged because I was not going sideways. So that leaves us with a simplified question: Does ABS and child systems function while in reverse?

Thank you guys for your answers and sorry if anyone is confused.

P.S. If anyone needs an excuse to "test," here it is :biggrin2:

Ok, to start I should mention that I am bored. Also I couldn't find a fish or a boat ramp.*Or a trailered boat for that matter!

I do have a long driveway that is wet on one side from it raining earlier so some standing water and leaves.*

So I jammed a wedge of ice from the cooler under the pass side front tire and put a rag on top of the tire to see if it moved.

Also I have an 05 V6 so not full time 4wd. Put it in 4HI center diff unlocked.

Backing up w foot on break abs or atrac would not engage. Rag never fell off tire. Abs light did not go on, throttle did not bog down and break pedal did not vibrate.*

When I gunned it throttle bogged down a sec and then ice wedge and rag became projectiles! Went to top of hill and gunned it then slammed on breaks at puddle w ice and leaves and abs did engage.*

My conclusion is abs and atrac does work in reverse. DAC only works in 4LO. I also think atrac or any traction control does nothing when pushing break pedal.

Does your trailer have a brake controller? I wonder if that matters or the weight of the trailer.
If I wasn't in nj you could lend me your boat and a trailer and a fish and I could try again!

 

[4boer2]

Wow thank you very much!

In conclusion: Due to searching on the FJ forum, medicrn's test, and JB.'s input, it is confirmed that ABS does work in reverse. So does ATRAC, a child system of ABS, as long as you don't apply the brake your self because that is a manual overide in a sense.

So why did my fish and medicrn's ice and rag not set the system off? Probably the system did not care because either it thinks 75% of traction is good enough or, as settytb suggested, we were going too slow. The world will never know.


lol

The trailer has surge brakes btw, so it works by momentum, no electrical input from the truck.