Nissan 370Z Forum - Unexplained Limp Mode

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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

Quote:

Originally Posted by Dallas-Z (Post 249835)

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

Quote:

Originally Posted by ejrives (Post 249853)

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.

Quote:

Originally Posted by Dallas-Z (Post 249863)

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?

Quote:

Originally Posted by AK370Z (Post 249874)

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...

Quote:

Originally Posted by Dallas-Z (Post 249880)

If I did not in fact hit the limp mode, why did the car decide to hold itself to 3500rpm and reset itself?

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

Quote:

Originally Posted by Dallas-Z (Post 249880)

The only other clue that could mean anything is I had just clock 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.

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:

Quote:

Originally Posted by MyATLz (Post 132069)

I have no mods and about 3000 miles on the car. It is the sport model 6 speed manual so it has the synchro rev match.

This has happened twice at random times. Car was running fine both times. Then I pull up to a stop light after downshifting. Then I place the car in neutral and it will sit at 2000 rpms. Then it will continue to rev. In the 2nd instance it got up to 3000 rpms before I put the car in 2nd gear and left the stop light. After moving the revs go back to normal. Then it happens again at the next stop light. Finally I get to my destination and turn off the car. I start the car up again about 15 minutes later and everything is back to normal.

Any ideas, suggestions? I am guessing if it doesn't happen all the time it's not that big of a deal. And if the people at Nissan can't replicate it when I take it to the dealer they won't do anything anyways.

EDIT: I guess I should have made the title more clear. Obviously it will rev while in neutral. What I meant is that the revs stayed high and continued to get higher.

http://www.the370z.com/nissan-370z-g...limp-mode.html

Quote:

Originally Posted by DinoJ (Post 145747)

This is very strange it's never happened before and i'm worried it could be something serious.

Today I was driving for about 20 minutes casually, not speeding or anything strenuous. It started raining very heavily and I had to stop the car when I got home, get out and put some things in the boot of the car from the garage. I left the car running while I did this (maybe 3 minutes) and then I got back in and began to drive away.

As soon as I got onto the road and tried to put it into 2nd the car started jolting very hard back and forth, same with 3rd, and 4th. I realised it was happening any time I took it to around 3k RPM. Engine temp was fine, (below 220).

So I managed to get home anyway and it's sitting outside now, i'm waiting for it to stop raining before I go check it out.

Is this limp mode? or something else? I did do some strenuous driving last night for about an hour or so on the track but I didnt get limp mode, drove it home fine, it drove fine today, and the temp last night didnt go over like 225 ish.

Any ideas??

http://www.the370z.com/engine-drivet...-gone-bad.html

Quote:

Originally Posted by jacobwf (Post 97110)

I went to test drive a base with sport package last week. There was someone in front of me that test drove it also, so I dont know if that had something to do with the problem I encountered.

I turned out if the dealer parking lot and got on it a little bit in first. Thats when the problem started. As soon as i hit 2500RPM it was like i was hitting a rev limiter. So I let off and shifted into second, same thing. Came to a stop light and started to go, not to hard either. Same thing happened when i got to 2500. I shifted to second, same, and to third and was still limited. Turned onto a side street and parked. Of course the sales person I was with didnt really know what was going on or much about the car. We turned it off and back on and turned the syncro rev match on and off too and it still was limiting me to 2500RPM. We then drove back to the dealer and another sales person took the car out to test out problem. He did not encounter it. The car sat for less than 5 min between when we brought the car back and the other dealer tested that car. Im pretty sure it was sitting longer than that from the guy that test drove it before me.

Anyone else hear of or encounter anything like this?

JACKPOT!!!
http://www.the370z.com/nissan-370z-g...eason-all.html

Quote:

Originally Posted by Gestalt73 (Post 127940)

Someone a month or so ago posted something similar on their first test drive out of the dealer's lot.

2009 370Z Touring MT6 w/sport package

Engine Oil temp: 200 degrees or so
Water temp: two dots from center
No warning lights or indicators
No over rev lamp
Haven't tried pulling codes

So, here I am driving along from a cold start, engine oil and water temps slowly creeping up, and as I get on the freeway onramp, the engine cuts out at about 3500 rpm, car slows down, accelerator reengages at around 3000 rpm. Interesting...

So because it sounds familiar, I just row through the gears keeping the rpms below 3500, and it consistently cuts out above 3500 for the duration of the drive. Other than that everything else appears fine. I have somewhere to be, and it sounds familiar, so I just get to where I need to go.

Get back out to the car a few hours later. She starts right up and behaves as if nothing happened. I'm going to bring it into the dealer in a couple of days.

Without codes or ability to repeat the symptoms, it may be helpful to see who else has had this, and what the fix is.

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

Quote:

Originally Posted by Pharmacist (Post 249999)

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.

Quote:

Originally Posted by 370Zsteve (Post 250076)

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 ;)