My 2010 G37x transmision is having an issue.
It will not go over 3,500 RPMs - it will upshift and refusses to downshift.
It doesn't matter if i'm in sport mode or even try to shift it manually.
If i'm on the highway and accelerate it just stays in high gear and wont downshift if it would cause the engine to be running at over 3,500 RPMs.
Thoughts??

 

There's no SES light or AT Check light on? Usually if a car wont go over 3500 RPM it means the cars in "limp" mode where it allows you to barely drive the car so you can safely get to your destination.

 

No - No warning lights are on.

 

Make sure snow mode is not activated

otherwise its a dealer issue.

 

Snow mode is not on either...

 

3500 RPM seems high to me for limp mode.

OP, is your car more or less stock? Have you ever had a professional tune?

 

completely stock. only dealer performed maintenance.

 

There is some chatter about a valet mode which has rev limiting capabilities, but this isn't something that's built into the car stock. Tuning software can flash your car's computer and enable rev limiting via a feature they call "valet mode", but the valet mode Infiniti provides us should only prevent the trunk release from working.

I still think 3500 RPM is too high for "limp mode". I think 2500 is the max RPM in limp mode, but I could be mistaken.

 

I'm not sure how my question will help, but while in Park or Neutral, you can indeed rev past 3500? And it will/will rev to 3500 rapidly?

In limp mode, getting any kind of RPM's is very slow process, or atleast was my experience in a G35x.

 

Havent tried to rev it in park or neutral. but it gets to 3,500 fairly well - which is why i didnt think it was limp mode.
I just filled up with gas - maybe i had a bad tankful of gas??

 

It should rule out the transmission right?

 

seems to be running normally today. weird...
new tank of gas helped - maybe??
will keep an eye on it and have the dealer look at it when it goes in next time.
thanks for all your feedback. JD