High Speed Off Road Brake "Failures" - aka Ice Mode

Headlines sell newspapers. I don't know if "failure" is the right term to use, but that's exactly what it feels like when it happens. I hit the brake pedal and it starts to brake for a split second, then changes its mind and braking power almost completely disappears - I go sailing into whatever obstacle I was trying to avoid. Tears and swearing ensue.

It's happened so frequently now that I've lost all confidence in the ability to brake and won't run shelf roads (a cliff on one side) at any kind of high speed. On unknown roads I pray a lot for no washouts.


I'm not talking about ABS engaging and making the pedal pulse. You can still stop pretty fine when this happens. You can also back off the pedal a hair and re-apply pressure to just barely keep it out of ABS. (for Alex or whoever when they read this, yes I've been capable of threshold braking for many years and can make a car dance around a race track. This isn't that.)

In this Ice Mode, the pedal goes stiff and does not vibrate like in ABS. You cannot back off the pedal and re-apply pressure - the pedal is 'dead' for several seconds and no amount of pumping will unfuck you from whatever you're about to hit. It makes you feel like a helpless passenger.


If you've experienced this "failure" you know exactly how it feels. If you haven't experienced it, it's kind of hard to believe until the rug has been pulled out from under you.

I believe this only impacts 3rd Gen Tundras. Ours is a 2014 and we have the issue. I was in a 2017 or 2018 the other night and experienced it. I've spoken to three others who have done it and they are 2015 and 2016.

I've been in @zackbremer 2nd Gen Tundra that is setup almost exactly the same as ours as far as weight and equipment - RTT and rack, Fridge, MT2 suspension, 37" Toyo RT. We ran the same stretch of trail in each other's trucks and my first comment when he braked was, 'wow, you can really stop hard!' I then proceeded to almost kill him in our truck when I tried to stop and overshot the turn at high speed into potential oncoming traffic. We got lucky.

Here is an unrelated video of us blowing a turn on Mojave Road where @osidepunker was right behind us and made the turn. I began to brake and it went to Ice Mode. I backed off and pumped, continuing to steer thinking I could grab some traction by backing off and re-applying. No love, just understeer and no brakes - smashed right over the berm.

https://youtu.be/mRPARO4eFKA


Here is some conversation about the topic as observed on race tracks in cars.

http://www.sccaforums.com/forums/aft/392890


My question is this:

If this has happened to you, what year or gen is your Tundra?

What kind of situation was it? (type of dirt, bumpy or smooth, turning or straight, aftermarket suspension, tires, brakes, etc.)

Have you been able to do anything about it? (pull ABS fuse, program with techstream, change brake compounds, etc.)

Tagging in some more folks who have either experienced this or I've talked to about it. @olsin6 @boardude @TRON @dragos28 @roypark @papasmurf @Spolar

 

Something similar happened to me while off-roading and coming across a turn that was sharper than I realized.

I was probably going about 40-50 over a mix or dirt and rocks. I don’t remember if I was in 4wd or not.

Hasn’t happened since

 

never had this issue, we run similar as well. And im in a 07... not sure whats going on but id deff discuss with a Toyota tech with techstream and have them disable that shit if possible. Sounds like disaster waiting to happen

 

Thanks man! I don’t know if 4WD is relevant or not, as I’ve had it happen in both 2 and 4. But good to kind of keep track. I’d be interested if you can make it happen again.

Good thought. I’ll have it checked out.

This is what makes me think the abs code changed between 2nd and 3rd gens. I don’t know of a 2nd gen that has done this.

 

Nope - drive better

 

This happened to me in a brand new 2016 Tacoma service loaner, and I had also read about similar issues in second gen Tacomas over at TW. Unsure what is the actual culprit, but I know that sinking feeling of a dead pedal that takes a few seconds to come back.

 

Or drink more.

Interesting. I’m not surprised it’s more than one platform. I know several cats that have done it too.

 

I had the inverse.

Accelerating and Hit two humps crossing an intersection and went limp, then truck powered up after.....

 

You do know why they don’t send donkeys to college, right?












Nobody likes a smart ass

 

That sounds like traction control kicking in under acceleration. The bumps caused the truck to go light and allow the tires to slip so the traction control pulled power to prevent them from continuing to spin.

 

So this is probably useless. On my 16 I had digressive valved shocks, Bilstein 6112/5160, and it did it. Scary. My 2018, and 2012 with progressive valved shocks, Fox, did/do not.

 

@KevinK I think this happened to me the other night, north of Florence, on that dirt road that goes back to AZ79. I thought this guy's explanation was pretty spot on to what I was doing at the time.

I wonder if the solution is a computer tweak, replace master cyl., or different brake pads/better driving..

 

Any information at his point is helpful. I do know that we’ve seen it on both progressive and digressive valves trucks, but still this goes in the data dump of my mind.

I knew you were on here somewhere and couldn’t remember your username to tag you in the OP talking about that night.

I ended up jumping the railroad tracks way faster than I had before and ran up the 20’ high berm with the whoop in the middle of it. I had wanted to turn left before the tracks and was in a similar situation to what you quoted.

Perhaps it has something to do with steering input combined with the braking and loose terrain?

 

I’ve had it happen in work trucks f150’s raptor and Tahoe’s. Not in the tundra, it’s mine I gotta pay for it.
Watching the video, I think it has to do with the bumps while braking. Abs doesn’t know what’s going on. Old broncos at work, no abs. Great in the dirt. Old 85 toy 4x4, 87 hardbody, (mine) no abs never issues in dirt.

 

Actually no, I don’t think steering input is terribly relevant. Possibly somewhat, but one of the first times it happened was on a straight trail approaching a washout.

Which we promptly launched into and out of at 45 mph instead of 15.

 

Yeah I’m strongly considering a hard switch on the ABS system to kill it offroad. Something that resets with the ignition cycle so the ABS works every time you turn the truck on, but can be killed with a button push.

 

That would be nice. Let us know if you figure that one out. I think you just pushed the abs computer shit beyond what it’s parameters could figure out and it shut down.

 

Some very interesting theories and possible causes in this Lotus thread.

http://www.lotustalk.com/forums/f100/ice-mode-track-solved-36810/#/topics/36810?page=1

I’m leaning steadily closer to the thought that ABS just can’t keep up when one or more tires are in the air and the surface is too slick.

 

I'd be really interested in having the ability to disable ABS for off road. Several of us have trac. control disable harnesses installed. I haven't experienced this issue but will keep an eye out for it this weekend.

 

That was me, but it wasn’t at speed. It was only noticeable when it was a long rolling stop. I haven’t noticed what @KevinK is talking about in my current Tundra, but did in my 2012. It turned out to be dissentagrated bearings in the front

 

Interesting topic. I've never heard of this til now. For what it's worth, I have a '15, but it's never happened to me. I've only gone off-road a few times here in Texas, but I was going slow in 4hi on relatively easy, flat trails. Given your description, sounds like this happens in 4hi at speed? But if your hypothesis is correct that a slick surface and having a tire in the air contributes, then maybe it could happen in 4lo under the right conditions?

 

I’m not sure Kevin knows what slow means

 

WTH! You havent even pulled the fuse yet to test it out and you're already "strongly considering a hard switch on the ABS system"

Look man, you're overthinking this whole thing. Yes, I have had it happen to me on my truck. Only a couple times on VERY loose surface. Not deep sand, but loose sand over hard pack. The bottom line is that you have to maintain wheel spin. If you lock up your wheels, it can happen. So I think you just need to:

I think your bald tires are exacerbating the problem. Put some good tires on and bet you it brakes better

 

Leave anything out?????

 

We talk about pulling the ABS fuse all the time, but no one I know has actually done it. From what I have heard, you will lose 4wd.

If you lose a speed sensor you get limp mode and no 4wd

 

Well, I smashed a speed sensor on a rock. So maybe there is a difference between shorting the signal and opening the signal.

there might be ways to hack the system like you describe. but I dont really care lol It's never been an issue for me and @KevinK can vouch for my driving.

 

Thats a great idea, ABS is stupid off road...

 

Yeah I don’t think it’s a slow speed event. It seems to happen when you’re really hauling ass and need to slow rapidly.

The first time it happened was in a straight line with almost new tires. I do think the loose sand over hardpack is the main situation. I’ve been reading how some abs systems will close the valves to rear in order to prevent additional brake pressure from going back there and causing a rear lockup. This leads to the hard pedal feel and takes several seconds to undo. It’s not like entering the pulse of abs and being able to back off and reapply immediately. The pedal is a solid brick for 5-10 seconds.

Alex can definitely wheel his rig. Seeing what he’s done in his compared to how ours responds is part of the reason I began thinking this affects 3rd gens and not 2nd as much.

 

2nd gen is superior race LOL