Unexplained Limp Mode
 

I've done some searching and I can't find anything that might explain why my car went into limp mode the other night.

I had finished a long flight back for work and got to the car around midnight in Texas. Them temperature outside was around 55F when I started the car. I drove about 18 miles in 6th gear at an average of 2650rpm (65mph). I turn off the highway and begin my back roads trip to the house when I'm startled to have no power.

At first I thought it was VDC pulling power but I wasn't even getting on the car, so I tried to accelerate normally and BAM, no power. Looked at the tach and it would hit 3500rpm and not give me anymore. Shifted to 2nd, 3rd, 4th and tested the gears, couldn't get past 3500rpm. Turned off VDC to make sure that wasn't faulting the ECU, still could not get past 3500rpm.

I had read that high oil temps cause limp mode, but I glanced at that temp and it was reading 180. Remember, it was a cold night and I was just trying to get home to get in bed. Now, I'm kinda freaking out because I can't even find a reason WHY it would want to go into limp mode. No warning light, no code, nothing, it was frustrating. Also, I assumed (also read around here) that limp mode was capped at 5500rpm and not 3500. So this also raises my concerns as to why it would do this.

If anyone has information on why or how to possibly find a reason for this, it would be awesome. I hope this isn't a trend the car will continue to have causing major work to fix it.

Thanks

Best bet is take it to the dealer.:tup:

I already did and I got "If it doesn't have a code, we can't help you". Also the techs really don't know what can cause a limp mode. I'm really at a loss with just an explanation.

sorry to hear that! I'd closely monitor for a while. I've personally never witnessed limp mode. All and all , It is a machine and is prone to fail ; nothing is perfect. Do some searching for the service manual, it's on here somewhere. Research what it says about causes.

I'd write to Nissan corporate headquarters. .

You DID NOT hit the limp mode. As a matter of fact, your stalling had NOTHING to do with oil temp. I have seen couple of threads like this but I can't seem to locate them now. I have to manually search them page by page. Give a little time. If I recall correctly, when they shut the car off, car reset itself and everything was fine. Did your car reset itself as well? did you unplug negative battery to reset the ECU?

I did not reset the ECU, I just drove it home and parked it. 7 hours later I fired up the car and couldn't get it to replicate the error. If I did not in fact hit the limp mode, why did the car decide to hold itself to 3500rpm and reset itself?

The only other clue that could mean anything is I had just clocked 3000 exact miles on the car during the 18 mile trip. But in order for me to prove this, I'd need a poster who is close to hitting that to test the before and after response of the car while it is still running, shutting off the car would just reset it. I wonder if there is any documentation that would point to a 3000 mile point and warn you of this "inconvenience".

Having to "reset" the ECU via disconnecting/reconnecting the battery terminal is poor quality i.e. unreliable. 1st year bugs I guess...

Not 100% sure why. Happen to couple members once and never happen again.

Hitting 3000 mile has nothing to do with this.

just a long shot...but when u started on the roads leading to your home..how much fuel did u have approx?

http://www.the370z.com/engine-drivet...e-neutral.html

not quite what you've experienced but happened exactly at 3000 miles :icon14:

http://www.the370z.com/nissan-370z-g...limp-mode.html
http://www.the370z.com/engine-drivet...-gone-bad.html
JACKPOT!!!
http://www.the370z.com/nissan-370z-g...eason-all.html
As you can see, it happened to 4 out of 11,xxx 370Zs that's on the road right now. Very uncommon. Never happens again once reset. Never happened to me either. I say just drive your car normally and if it happens again, straight to the dealer.

thanks.

AK

like someone said before, could be a sensor that malfunctioned or was accidentally disconnected. things like these can confuse the heck out of the ecu. i remember once i was doing work on my old intrepid, and forgot to reconnect the camshaft position sensor, which caused the ecu to cut engine rpm at 3500

Yes....Limp mode can be caused by any number of things. It usually involves a sensor that is not outputting enough of a signal, or one that is out of range. The ECU sees this and decides it is not happy with allowing the engine to rev above XXXX RPM's with that particular sensor value where it is.

It's either a Glitch or a genuine problem. Re-boots fix the glitches..

Somebody please find my old Buick that only had an engine with 8 spark plug wires and a couple of coolant hoses outside the block and nothing remotely resembling a computer. Thank you in advance.

got a 71 c10 c/d sitting in storage. has a very similar motor ;)

Well this news is decent good news that others have seen the same problem and even mention the exact rpm (3500) that I saw. I just want to see if the there is a common cause for it that might need a recall or at least documented so it can be fixed later under warranty.

Stage 2 limp mode, otherwise known as drive it to the dealer mode. In this mode the engine power is cut by disengaging the variable valve timing, limiting fuel and air intake and limiting RPM to a low number - 3500 in our case.

Typical reasons are:
- Engine overheat past 300 degrees (not applicable here)
- Bad readings from crankshaft position sensor

It sounds like a software glitch given that there is no code thrown. Who knows, the programmer could have left some test code in there that was supposed to be removed but never was. If it never comes back I wouldn't worry about it. If it repeats try to drive to the nearest dealer without shutting off the engine.

hey dallas! just like what the other had commented i guess you need to inquire on the dealers itself ...a glitch or a manufacturing defect may cause this..not really sure coz i havent experience it in mine:driving:

I am in Chattanooga TN and just went for a coffee run in my 40th. Hit the onramp at 75MPH and my baby handled wonderfully. Tight and straight through the clover leaf.....once I exited the turn to hit the striaght line onto the highway, I had no power. I could only do roughly 40mph and had to pull over, turn her off and back on. Once back on, no issues at all. Does this "limp mode" have to do with some sort of G force during the turn or maybe a loss in oil pressure due to the turn?

Thanks for any assistance.

^ Wow this is scary. I thought this only happened to 09's? Now it's happening to 10's too? Luckily, nothing for me yet, though I only have 1300 miles on my 2010. So is the consensus that it's just a sw glitch and not really an issue since you just shut off and restart and problem is gone?

So here's a better question.... WHO has had this happen to them AGAIN, besides the first time?!?!?!?!? Because if someone has had it happen to them twice, then there's something definitely wrong.

Limp mode eh?

Toss a couple of these bad boys in your gas tank..might even give you a few extra ponies :tup:
http://www.das-original-viagra.com/i...gra-kaufen.jpg

In all seriousness though, maybe you could try disconnecting the battery for 10 mins and see if a reset helps it?

Agreed. Nissans are very reliable but they are also very glitchy. There's always these little unexplained problems that come and go that really don't add up to anything in the end. I say do the reset. If it returns push the dealer to check it thoroughly. Even if they don't find anything, cool. Better safe than sorry. At least it will be reported that it was checked for the problem. That way if something goes wrong? You got eem by the balls. Keep all your reciepts.

I had this exact same issue a couple of months ago it was in Jan, I heading home from work going up a mountain range when all of a sudden I noticed that my car lost power and would not go past the 3500RPMs, the only different from mine and the post is that I pulled over and turned off the car it was not hot all temps where good. But when I turned it back on the check engine light came on. I took it to the dealer and they replaced a censor which was faulty.

this happened to my co workers friend. She sent it back to the dealership and they could not get it fixed. They did not know what happened. So they gave her a choice. a new z or they paid her back in full. She got her money back. It sucks cuz she has had a z since it came out in the 60's.

mine did this once when i first got it. first 100 miles... thought i did something wrong turned car off turned it back on has not happened since 20k+ miles

what sensor was it?

The story about losing power during an on-ramp turn and then having to restart the car is fuel starvation during a sweeping righthand turn. This is an issue with any model year 370Z.

Interesting... so only apparent/evident when tank is 1/4 full or so during said turn?

correct

Unless it is on a race track with race tires, in which case it will happen with 3/4 tank or more. On typical street tires 1/4 tank is the typical threshold.

Sorry to bring this back up but this is the exact issue im having right now... Has anyone figured out the cause? :/

Check your brake switch. If you have access to an area with no traffic you can test this by pulling the brake light fuse.

yeah fuel starve

ChrisSlicks, i'm struggling to cure my random limp mode problem.

Mine hasn't limited me to 3500rpm but instead the revs while in gear just take forever to climb, as in the car accelerates extremely slowly. Throttle position seems limited to 15 degrees.

My brake switches are fine and adjusted per the manual. Conditions were cool and it's definitely not VDC. No dtc or CEL.

Both cam and crank sensors fail the resistance tests from the manual. Pin 3 seems dead. Car starts and runs fine until the random limo kicks in. Idle is smooth with the occasional sag to 500rpm

I just rolled 3k yesterday and haven't had a single issue to date.

My 09 just started doing this too. However it just got tuned on the dyno and I feel the tune might be the issue. Ill be doing 55-65mph and go to pass some one with moderate acceleration, hit maybe 75 mph and it sometimes goes into limp mode. I cant rev past 2-2.5K rpm. Ill turn off my car, wait 10 sec, restart and be fine. This has happened twice now and its starting to annoy me.

Would a dirty throttle body have anything to do with this?

I know mine was giving me minor rpm issues and drops till I cleaned them. It has been a couple of weeks and she is still running like a champ.

Maybe it is sticking?

throttle bodies are often first to blame. whether it be due to sticky flap mechanisms or throttle position sensors which chuck a wonky reading.

i cant remember who it was on here that suggested out of sync throttle bodies as the issue. i've datalogged my throttle bodies and they're about as perfectly in sync as you can get them.

shfeddy - you have a supercharger kit so that adds another variable. but i think a fair few folks with tunes have experienced the random loss of accelerator response. this makes me think there might be one cell in their tuned throttle maps which the ecu doesnt like. hitting that cell would take a certain combination of inputs so it's hard to replicate. i'm still standing by my throttle tune - it's the same map that's been posted up on these forums and most folks have been troublefree so i'm ruling that out for now

I just experienced this yesterday. After pulling onto a highway, my 09 Z started to hit the rev limiter @3500 MPH. I just drove it below 3500 until I stopped at a restaurant. After leaving the restaurant, it was like noting happened. I guessed it may be software related, so I hit up the Forum, looking for answers and came across this post. I guess no one has found anything definitive as yet so I guess we just keep on having fun in our Z

This ^^^

Read page 4 from the thread i started, and an update in another thread that you will also find in page 4. Dealer cleaned throttle bodies and recalibrated them. Same issue happened to a friend of mine from this forum. Neither of us has had the problem since then :tup: