Braking problem - malfunctioning ABS

alan93rsa

What you are describing is exactly what happened to me at Putnam Park in the S2000.

At Mid-Ohio with the 370 I ran the stock pads with Motul RBF 600. No brake fade but the laps were limited due oil temps issues.

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JeepTodd

I have seen some weird brake problems, very similar to what yo are seeing, that are from a tiny air bubble in the ABS system itself. I am told you have to bleed the brakes with the ABS cycled open. The ABS cycle is different for every car. The easist way is to have a dealership computer cycle it. Otherwise there should be some sequence of things you can do to cycle it open.

ChrisSlicks

Thanks guys.

I'm taking it to the dealer in the morning, see if they can cycle the ABS controller and pop that bubble outta there.

ChrisSlicks

I took it to the dealer this morning but the technician was unable to reproduce the problem, which isn't altogether surprising. He's going to talk to Nissan engineering to get their opinion but somehow I think I'm going to end up on my own.

I'm going to bleed the brakes with the car running and see where that gets me. I'm going with the ATE Blue fluid for now.

wstar

Without a computer hooked up that can talk to the ABS controller, you won't be able to properly bleed an air bubble out of the ABS. There are tools available that can do it for most cars, it's kinda like hooking up an OBD-II code reader (same socket), but the tool talks via CAN to the ABS computer and can instruct the ABS to purge itself, etc. This tool: Actron® does it for ~1996-2005 domestics, but probably doesn't cover our car. Or you can just have the dealer do it.

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ChrisSlicks

Yeah, I was afraid of that. Unfortunately I think I'm going to have a hard time convincing them to bleed the brakes even if I offer to pay for it. They're acting all suspicious now, the service writer walked around the whole car checking it out, looking for what I don't know ... signs of abuse maybe? I drive my car hard but I don't abuse it.

cossie1600

Ice mode, happens to the C6 a lot too

RCZ

Yeah this happened to all of us who track the car hard, even with upgraded rotors and pads I remember someone went into ice mode.

I think Travis no longer goes into ice mode...because he has AP Racing 6pots....

simple fix i guess haha

davidyan

As the temperature of the fluid increases, the pressure will increase while applying the brake. (although it will not always translate to higher braking power)

One possibility, is that the hot fluid and high pressure is triggering your emergency brake assist system. Maybe a little far fetched but wanted to throw it out. Most brake assist systems trigger based on the speed at which you hit the brake but could it also be somehow linked indirectly to brake fluid pressure? Also, the ABS sensor also detects brake pressure which could be thrown off by the high temp.

travisjb

As RCZ mentions, with my AP Racing BBK I am not getting any of this... and I definitely had it before - I remember 'icing' my way towards a wall at Phoenix Intl Raceway !!! not something that is easy to forget... can someone verify where they abs sensors are located ? I suspect with the stock setup there is heat being transferred to the sensors which is throwing off the ABS computer... with my setup, heat is dissipated much more efficiently... yes $$ to upgrade... but sh1t- why take chances on brakes! here's a thread on the apr kit AP Racing Big Brake Kit Installed!

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2009 370Z #104
*For Sale*

import111

I still not only have not had this issue...but quite the opposite. The hotter my brakes get the better they stop me. Other people have ridden in my car and driven it and they agree that the stock brakes on my 370Z are insane and stop hard as hell.

travisjb

they are good brakes, until they overheat. come on up for the september nasa event at PIR and i'll show you exactly how it works

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2009 370Z #104
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bullitt5897

I have experienced the "Ice Mode" before too... Its a creepy feeling especially on the street when you need to drop 30+mph to make the turn LOL. I learned to let off and re-engage the brakes and it goes away. But dont worry I will have Alliance 8 Pots 15" 2 piece rotors real soon! I cant wait for the slam your face into the windshield braking... The sport brakes are good but these Alliance brakes are going to be the Sh1ts! I will post up pics and reviews when they are finished and come in. I am starting with 8 piston front and after those are done they are going to make my 6 piston rears!!!

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Shop Cars: 2013 318whp Nismo VspecII 370z *SOLD*, 2009 1000hp+ 93oct 4.0L TT 370z Fast Intentions STAGE 4 #054

boosted180

has anyone measured any temps to see at what point this happens? i'm going to an auto-x this sunday and will try to get some readings. but at a typical auto-x, the brake temps may not go up enough to cause the problem. will see.....

travisjb

I'm going to revive this old thread... new information

So, despite adding a massive AP Racing BBK and taking hundreds of pounds of my car, I'm still getting the icing issue on occasion. Happened to me today at Firebird Intl Raceway. I was going towards a carousel and braking hard to get set up at the correct speed and on the right line. I had just passed another car and had to make a big transition that upset the car's balance... then bam - icing set in and I began a slow terrible grinding towards the outer part of the track and straight-line braked (but not nearly as fast as I would have liked!)... nearly ended up 4x4'ing. It was total ABS lock up, but as has been previously described it was v inefficient with slow pulsing like riding on ice.

It didn't happen for the rest of the day.

It was NOT an overheat issue b/c it was early during a session.

As it turns out, there was a fellow at the track today who happens to be a test driver for a certain car mfgr that we know and love. Please don't ask me to elaborate. He says that the 370z and the 350z before it have had this issue. What happens has nothing to do with overheating. The ABS computer is kicking in icing mode when it senses any one wheel turning at a substantially different rate than the others. Confirmed it is a different mode than normal ABS when limits are exceeded.

We discussed potential solutions. His belief is that there is NOTHING that can be done except to get an increasingly stiff suspension that is less likely to result in 1-wheel up or other conditions that allow wheels to spin at differing rates.

Not sure where to go from here, but figured I'd share these thoughts.

So, anyone else have 'ice mode' recently? Anyone thinking about how to fix?

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2009 370Z #104
*For Sale*