I have been having the same bad shift issues. I felt the shifts being too jurky and I went to the dealer. instead of fixing the problem the idiots told me they updated the ecu and after that my car feels a lot slower. I went back and he said it was from japan and he cant do anything about it.the rentals i drove never had that problem.

 

Gevo1: I was very pissed that the the Dealer, who has been terrific until this occurred, reflashed the ECM. The Service Manager listened to my complaints and ordered the new ECM WITHOUT application of the TSB 08-017 (update to ECU) for a surging and touchy throttle issues.

The jerky shifts you mention seemed to come from the Valve Body in the tranny. That was replaced a few months ago after I complained of the harsh 3rd gear shifts. The Dealer ordered it and replaced it under warranty without question and Their prompting. Pepe infiniti, White Plains, NY

 

Thanks a lot man, I got an appointment for wednsday and Ill be sure to tell em about it. Thanks again

 

Gevo1: What happened at the dealer?

 

Sorry I forgot to post back. I left them a bunch of things to do and after two days all they did was fix that crack we get on the left side of the cluster. Everything else they just wrote that the computer showed no problems. I even told them that I dont care what your comp. says, reprogram my ecu back and fix my tranny. So then I left a bad report and I want to go back and really talk to all of them this time. Its just that Ive been to busy lately. But atleast I mest of their loaner realy well and gave it bak on dead empty lol.

 

I just bought a used 07 G35 sedan and I am having that same jerky transmission feeling. Also, when I first start the car, and shift from P to Drive, it gives a hard throw feeling before I release the brake. I told the infiniti dealership about the problem, and they have stated that the transmission fluid is thick when cold and will shift hard early. However, I never had this problem with my cheaper Altima and Honda Element. Is resetting the ECU as simple as unhooking the negative connection on the battery?

 

I have changed my driving style (aggressive to soft) since (june 08) I brought my g and I was getting those jerky shifts. I resetted the ECU last week and everything is very smooth now, even my friend who drives it sometime notices a big difference.

 

I hooked my battery back up, and I think the ECU is resetted because the car does drive alot smoother. I dont know if its my imagination or what. My radio did not lose the presets, but my mileage and MPG was all reset. I left the battery unhooked for 8 hours. I hope it was enough time.

 

I don’t think this tread is getting anywhere, not because of lack of suggestions, but because there are just too many variables to provide consistent input describing the issue. As all of you know, there are many different ways to shift the car and in addition, various driving styles, road/traffic conditions and even model year of the car with or without TSB fix, etc. All these conditions need to be described if you want to ask if others if they are experiencing the same issues.

To the OP … the best way to resolve this is to take a comparable car out for a test drive with a tech or the service advisor and see if it behaves the same way as your car does. If not, then you may have the evidence you need for warranty work. I am still not sure what mode you are shifting in, D, DS, or M when the issue shows up. Can you recreate the problem whenever you want?

I do not have a 2008 so I can’t really say how they are supposed to shift. But I can say that in my 2007 driving in D mode and in all conditions, the car shifted very smoothly with no jerking between upshifts and downshifts. Very much like the sport-luxury car you have. The transmission tries to get into the high gears as soon as possible (too soon IMHO) under no load conditions.

Things change when you go into DS mode. Again, in DS mode, the car can behave as if it were in D mode at one end of the scale. At the other end of the scale, it can behave like a race car and will even hold shifts until redline. It all depends on the input conditions provided to the TCM.

When you first flip the lever from D to DS mode, the car will drive the same until the TCM thinks you want to drive aggressively. This can be triggered by sudden braking, hard cornering, and heavy acceleration. Once this occurs, upshifts occur at high RPMs (again, even up to redline) and downshifts occur much earlier in the RPM range giving the jerky feeling. To confuse things even more, I’ve noticed that the TCM “resets” after coming to a complete stop. Then after accelerating away slowly, it will revert back to feeling like you are in D mode again until it once again senses “aggressive” inputs. So if you floor it on acceleration instead, it will stay in aggressive DS mode. I personally like to drive somewhere in between the two ranges so I shift manually most of the time.

Anyway, the point of all this is to help understand the transmission logic and hopefully the OP can use this info to see if he can recreate his “problem”.

Sorry so long … I got carried away.

 

That was a great description of the driving modes. Spot on the way my 07 G35X seems to perform. My ECU was "replaced" after the dealer applied the 08-017 TSB which could not be reversed. I did NOT ask for or request that TSB reflash application to be done. Anyway, the cars is performing ALMOST like old. There is a slight hesitation and rough idle at cold engine start up. Going tomorrow to my Dealer to have the 07-045a (issued 4/27/09) applied that addresses this issue. It's Machines controlling Man - sounds like BACK TO TERMINATOR......LOL. My first car, a Chevy Malibu - with a 350 V-8, didn't have "TSBs"...