Traction Control, Sticky gas pedal, Ice mode???
 

So, I have been meaning to read a couple of those brake threads but just have been really slammed with work lately. One thing I keep picking out from random threads is the word 'ice-mode' and how people are getting this condition particularly when upgrading brakes.

Now, I haven't upgraded my brakes yet, but I have experienced quite an awkward sensation a few times since I have owned the Z.

Where to begin....

The first time I experienced this was when taking a long sweeping turn aggressively (with traction control on) and upon letting go of the gas the car just seemed to coast and hold my mph...almost like it went into a cruise control mode and kept me on this perfect line where it knows just how far I can take the car without losing traction...I remember thinking to myself "WOW What was that? Some kind of active traction control system like in Formula 1"

This sensation of the gas pedal having a mind of its own has happened maybe 4-5 more times in the last year but almost under similar conditions. Until about 3 days ago. It was a gorgeous night and we were tuning my friends MR2 Turbo with my car, a supra, rs4, and m3. So we are all kind of taking turns doing some baseline pulls with him where suddenly after one of my pulls I downshifted into 2nd after leaving the highway and my car just held this low mph and wouldn't stop. This was, mind you, in a straight line...

I knew it was the same sensation I've had before, just never having felt it in a straight line kind-of threw me for a loop. What happen next, really had me wondering whats going on...

I put it in neutral and coast the last 50 yards or so to the stop light and as I begin coming to a stop, my car decided to just keep the revs at 2k. I looked down thinking my carpet or something was hitting the pedal but nothing! So I have make sure my foot was on the brake and it just continued to keep the rpm at 2k...It did this for about 5-6 seconds when I simply blipped the throttle and it settled down to idle and then it never happened again.

Sorry this had to be so long and hopefully I'm explaining my self clearly but has anyone else experienced this and/or is this ice-mode that you guys are talking about specifically where the car feels as if its holding a light throttle whether in turns or not??

Thanks!

No one?

You sure you didn't buy a Toyota on accident?

I recall someone had a problem with the srm and the car revved about 4k when he was coming to a stop. Nissan looked at it and fixed it.

toyota lol, believe me the thought crossed my mind.

Danny
I had the exact same symptoms in second gear but the only difference was that I had the traction control off everytime it happened!
On all 3 occurences, the revs keept the car pushing in coners... Not a good feeling coming in the corner's apex... So far it never happened in a straight line.
I had the same reaction as you did (looking underneath the floor mat etc) but could,nt find any objects in the way.
Anybody else having this issue?
Phil

I think this happened to TheWeatherman (someone correct me if I'm wrong)... turned out to be a faulty SRM sensor or something.

Interesting, I had the same thing in second gear on an exit ramp with a slight downgrade. The engine did not seem to slow the car down. Happened maybe 2 or 3 times in the 10 months I had the car. Thought maybe it was the downgrade on the ramp but I drive the same ramps all the time and just did not feel right.

Ya I want to make a correction and say this has happened to me with and without TC on. But always with SRM on. So when it happen for the first time going in a straight line it REALLY freaked me out. Not to mention when I came to a complete stop and it blipped the throttle and kept it at 2k for 3-4 seconds.

Same thing tho, this happens rarely and maybe 5-6 times in the last year...

not trying to jack this thread but DannyGT have you had any problems with your GTM oil cooler? wat are your avg temps in NJ?

No thankfully not. Had it for something close to 8-9months now and its working perfectly...Even on the hottest days so far at highway speeds it will consistantly stay around 185-200...and in traffice never go about 220-230.

Its great! Alot better than running 260+ under normal spirited driving before I got the cooler.

My lines are working. I know some had received bad lines and I think thats all it was, bad lines. Sam is actually sending me new one's, just because. I told him to send it to me when I receive my SC kit.

Ya it has happened to me a few times, first time it really took me by suprise, mines a 7AT btw

thanks for the reply...i think ill just go with this setup. Defiinitely cant beat the price. appreciate it:tiphat:

You'll have to have the dealer look at it. The accelerator pedal may need to be recalibrated or worst case replaced. In these fly-by-wire systems the pedal sends a voltage to the ECU, and the ECU has to "learn" what the correct voltages are for the pedal up position as they can vary slightly between pedal units. The SRM is another possibility, but given the description from all your events I think the former is more likely.

Chris,
Went to the dealer with this issue... out of luck with that one. The head service guy looked at me like if I was coming from Mars... They said that my foot must have been touching the pedal of something was in the way :icon14:
May need to go somewhere else on this one. Since there is no TSB on that matter, does anyone got it fixed by a dealer?

I can point you to the chapter in the service manual that describes the procedure. It can be performed by anyone that has a Consult III, which is basically Nissan/Infiniti dealers. It is really sad that 90% of the Nissan mechanics have no clue about the detail of how the electronics work in this car.

If your dealer isn't responsive just call Nissan Consumer Affairs and tell them that your vehicle is accelerating by itself. You will get their attention I promise!

Chris,
Going back to the dealer next week on this one. I'll keep you informed on the results... I hope not to have to rise this issue to a higher level since it looks like a "normal" maintenance/troubleshooting issue.
Phil

It's a rare occurrence, which is probably why the dealer is a little clueless. The pedals get calibrated to the car at the factory, and usually that is that. But it is possible that the original calibration wasn't perfect or something else changed causing a slight differential.

I guess I will call my dealer up tomorrow. I have a fairly good relationship with them so hopefully I can get some answers. I still dont know what to think...I can see it being the SRM or the Pedal calibration but I think I'm leaning more towards something to do with SRM. Then again, when it rev'd to 2k for a few seconds while my foot was on the brake and the stick in neutral I dont know what the heck to think...LOL

If it only revs for a few seconds, then it is SRM. SRM doesn't care if you are braking, and it is active in neutral (can detect neutral gate position). SRM shuts down after about 3 seconds after you leave a gear.

If it revs for longer periods of time, especially while stationary (SRM is disabled while stationary) then it is a pedal problem.

Well that confuses me even more, LOL...

The very last time it happened on a straight away, I came to a complete stop and my foot was on the brake and it still managed to keep an extremely precise hold on 2k for, I dont know, maybe 3-4 seconds. (with it in neutral) I didnt wait long enough and just blipped the trottle to see if it would get out of that mode and sure enough after I blipped, it dropped to idle normally.

Sounds like pedal then. The pedal is sticking just every so slightly. Recalibration might work, and it can even be calibrated with a slight deadzone if required. Ultimate solution would probably be to replace the pedal unit.

Well, good news/bad news....

Bad news, it was doing it ALOT today with and without TC on for the first 15-30 minutes of my drive and randomly on sweeping turns where it would just keep the gas at a certain rpm.

Good news, I was almost kinda maybe (lol) reproduce it at will and I do think it now has something to do with the pedal. I was able to notice when it would particularly hang at a rpm, shift it into neutral and then blip the throttle enough to get it to stick. At the moment, I was like "AHA!" So I'm going to get deep in there tomorrow morning and see if there is anything that obvious and physical that might be causing this. If not, its going straight to the dealer and I'll request a new assembly.

Also, I want to point out that it never accelerates further than where it gets stuck. Example; if I'm taking a turn and the rpms go from 5k to 3k as im slowing down, it might get stuck at 3k and simply hold that rpm until im complete with the turn. Its still a very wierd sensation and its a bit scary but I never feel that its going to race through the gear and kill me either.

Danny, what you're describing is not ice mode. Ice mode is something that is happening to some guys who have upgraded their brakes with BBKs. What happens is that the larger brakes have so much bite that it confuses the ABS into thinking that the brakes are locking up. So then the ABS releases the brakes! Bullitt5897 got the Alliance BBK, and a few weeks ago he asked if I'd meet up with him to do some side by side 60-0 brake tests and make a vid. I said sure. So we taped off a 100-ft. distance. My car was able to stop in 64 feet. His car would go into ice mode -- the ABS would ease off and allow his car to continue forward, not clamping down again until he was well past 100 feet. So oddly enough, upgrading our brakes on this car may actually backfire! Bullitt's plan right now is to swap out the brake pads to a less aggressive compound to see if that helps by dialing down the strength of the initial bite.

You can read more about it here: http://www.the370z.com/brakes-suspen...tml#post481605

Just to be sure... please tell us if you are doing right hand or left hand turns when this happens... and how much fuel is in the tank when it happens... 1/4? 1/2?

try to make it happen with a full tank in a left hand turn... if you do that, we can rule out fuel starvation... but,

it almost sounds like fuel starvation given you are talking about the throttle cutting out on you... please describe it some more... is it a hard cut off at a very specific RPM - every time... or is it a loss of throttle and you just *happen* to be at a lower rpm, like 2,000?

RE the braking issue... which I don't think is what you're having, but I'll respond to this

My temp solution is to continue firming up the suspension... don't know if this will work yet... but after talking this through with a nissan test engineer that has 1,000s of hours tracking 370z's, I'm pretty certain the root cause is differential wheel spin rates... ie one wheel picks up off the ground (or just slightly) and spins at a different rate, freaking out the computer and putting it into a safe mode / ice mode braking condition... there might be an RPM cut-off that engages with this ice-mode, haven't confirmed... in any event, a very stiff suspension should minimize the wheel lift... obviously not a solution for everyone... the alternative right now is as chris says go with gentler brakes that are less likely to slow down any given wheel abruptly or perhaps find a different abs computer... no real good solutions just yet

Trav, its not a cut off...

I dont want to say it accelerates because that makes it sound close to what the current issue is with some Toyota's. More like, when it happens, it HOLDS the rpm and throttle at that position for a few. It feels as if its driving itself for a few seconds while you pull off the throttle. Imagine you pulling off the throttle while your going around a bend and something gets caught in the pedal and you continue at that position instead of the car gradually slowing down.

The thing is, I have been able to sort-of replicate this while going straight and coming to complete stops and having the throttle peg'd at 2-4k rpms. I'm really leaning towards a pedal calibration.

Danny, I'm at a loss... I'm pretty sure that's never happened to me. Your theory about pedal calibration is as good as anything I might come up with.

Anyone know if Nissan is using the same pedal assembly that Toyota has been using? Not trying to be cute, here... who makes our pedal assembly?

Danny if it is happening at 2K-4K then calibration isn't going to fix it, that only fixes the off idle position.

There is either something causing the pedal to physically bind and stick in a position or there is something wrong with the resistive strip. The inside of the pedal isn't all that unlike the fuel sender, if contaminates get on the surfaces it may misbehave. But other than checking for binding issues don't take your pedal apart, just get it replaced.

Danny,
I had it again today, but this time is was between two boulevard stops. Fuel tank was full and engine at normal temp.
Did try to reproduce the isse without any luck. On Friday, the dealer told me that if they can't reproduce the issue, he doughts they can do anything :icon14:
Leaving the car at the dealer on May 6th (the whole day this time).

i only expereience this when my engine is cold and at start up. the rpm rises and stays around 2k but thats expected. sometimes when i start it up and dont let it warm up and put it in gear and slowly let go of the clutch, the RPM rises and accelerates the car on its own for about 5 secs or so.

normal right?!?!

Yup. On a cold start the car can pretty easily go on it's own since the revs are high.

I did get my car detailed on Friday and I have been driving it alot since the weather has been great the last couple of days. Hasnt done it again...Hhhmmmmmm

Maybe your sticky pedal was ... well, sticky?

Sticky pedal - Nissan Canada answer
 

So I got the car back for the dealer today.

Since they weren’t able to reproduce the “sticky pedal” symptoms, they decided to contact Nissan Technical support.

They were told that was a “normal” situation!!! :confused:

Told them that I never saw a car that maintains RPMs level when you remove your foot from the accelerator…

May have to contact Nissan Customer if this problem reoccurs.

In the interim, I’ve disconnected the battery to reset everything (hoping it may help…)

if you keep the battery disconnected, that will definitely solve the problem
- Nissan Customer Support

Lol. Toyota Customers Affairs also said that!!!

DannyGT...

Did you ever get this issue resolved?

One day, a couple of months ago, my engine started slowly climbing when I put it in neutral. Sometimes blipping the gas pedal would bring it back down to the proper idle, sometimes I had to physically pull the pedal forward by putting my foot behind it. I let it get to 6K before stopping it once just to see how far it would climb.

I drove it straight to the dealership and, of course, it had stopped doing it once I arrived. But, it didn't happen again until last Monday when it started happening constantly. That time, I was able to get it down to the dealership while it was still doing it.

The service manager and a technician were both able to reproduce it. They wrote it up and told me the first available service slot was on Saturday.

On Saturday, they told me they checked the throttle bodies, reset the idle, but couldn't really do anything until they called Nissan tech support. I was rather irritated (and expressed it to them) with the service people for not doing that ahead of time. The guy just started getting an attitude and basically said they couldn't call Nissan until they looked at the car. Whatever.

Today, they called and said no one at Nissan has ever heard of the problem and my only option is to call Nissan Consumer Affairs. ...which I planned on doing anyway because I really do not like the dealership.

No never got it resolved. I can still reproduce it with TC on and taking a turn in a mild-manner and getting off the gas...boom the car just decides to hold that RPM and finish the rest of the turn for me, LOL. Its really not funny, but I still think it could be suspension throwing off how the traction control is trying to apply power to tires that may be slipping. I dont know what to think really.

Its only happened in a straight line/coming to a stop twice which tells me - sticky pedal...But as I said above with how I can reproduce it on turns, tells me...traction control??

Good luck with Nissan customers affairs... Can't wait to ear their answer on this matter!
I've been told that if they can't find any data in the ECU and the fact that I can't reproduce the problem, they can't do anything.