I have over 600 miles on the ITB12-027 update and this morning I had two instances where I experienced lag in "D" mode.

First occured about 5-10 minutes after I started it this morning. Temperature was about 45F outside. I was making a right turn onto a two lane road. First turned into the right lane, then moved to the left and hit the gas....then nothing, then rev/shift, then accerleration. Duration of lag is not as long as it was before, but noticable.

Second occurance while merging onto the highway. I had to slow down for someone who refused to let me in and slide in between him and the car behind (before running out of road). After lifting off the throttle and getting back on it to merge the car paused again, rev/shifted, then accelerated hard. Again not as bad as it used to be but still annoying and made me doubt if I would make it.

 

Malu: I have over 250 miles since the Reflash was done. I sense a little lag now and then as well (especially when still cold) ..... It's still better than what I had before the Reflash as All of You know from my persistent complaints. Afterall, even though the 7AT is only 2 years Old (in the 2010s), with 7 gears, it will always have a little lag -gear hunting going on. But it is signifcantly improved. Throttle response is ALMOST as good as the 2007 G35X I had (5AT).....And yes, a little better mileage- I see that too...

Without Regurgitating old comments, I have associates with Lincoln MKS' with 6 or 7 gear Auto Trannies....they have lots of lag and quikiness/ abrupts shifts in certain driving situations. In fact, one friend has had them reset the ECM/or ECU (different car makers call it different names), on a number of occassions (not Reflash it with new software changes - just Reset it). The car performs better from the get go, then reverts to old behavior. I am Quietly Confident that won't occur here based on the actual Software changes which eveidently has chnaged throttle response and shift points. Isn't great to drive COMPUTERS....Who knows next car could be a MUSCLE ONE..

 

I think that with the bulletin update applied, the car is probably hitting the performance limits of the 7AT design. With a 5AT, there is a much higher probability that when you hit the gas, you're already in the 'correct' gear. I think with the 7AT, when you get the lag, it's when you're hitting the gas when the transmission is in a semi-shifting mode due to coasting. It has unlock the torque converter since you're coasting, and is waiting for the car to slow down to down shift. When you surprise it by hitting the gas it has to re-engage/relock the torque converter and force the downshift and then rev up the engine.

If the car was more aggressive with unlocking the torque converter and holding the existing gear while coasting, you'd see higher RPM's and probably worse gas mileage, but faster response.

I'm not making excuses for Infiniti - I think the design can continue to use some refinement. But nominally after having the update applied I can say I'm 97% satisfied. Overall, I consider the value/fun of the car to be a weighted sum of all the parts - engine, transmission, body style, handling, features, etc.

Anyway, we also have to face the fact that the G37x isn't a high performance sports car. It's a high power luxury car.

 

Thanks Malu. Spoke to dealer today. Car is still with them. They promised to look into it today. In the meanwhile, I cant complain driving the 2012. Even my 4 year old son told me (I am not making this up!) that "dad, i like your new car more than the old". His reasoning was the torque he felt in the 2-3k rpm that he did not feel before. What more can I ask for ?

 

What you need is the M3 or Cayman

 

Dus1101, You are on IT !!! The G37X is categorized as Personal Performance Sports Sedan...too many "buckets" are used today. Happy Motoring !!!

 

+1 Insightful, good viewpoint.

 

I don't mean to split hairs but I think you've got that backwards with the TC lock/unlock, unless I misunderstood you. The TC should be unlocked during shifts and while accelerating under moderate+ throttle. When you hit the gas suddenly, it should immediately unlock whether or not a downshift is called for.

 

I went in this morning to get my 09 checked out. I told them about the issues with harsh downshifting and the acceleration delay. They said they will hook it up and check if there is an update available for the ECM.

The rep said there is no update available for your car at the moment, and that the tech has noted it as normal behaviour. The rep said that next time you come in we can check again for an update, and it's all about software in these cars.

So maybe the ECMs are different from MY09 to MY10-12 cuz the computer didn't show any updates. I hope they do come out with an update for the 09s, we have suffered the longest!

 

Yes I think you're correct here - I didn't describe my thoughts very well in that post . Assuming I'm cruising along, the TC should be locked up. If I then hit the break, followed by the gas to accelerate, I 'want' the TC to be unlocked to get the engine torque to the wheels with maximum power as the expense of efficiency. Consider however, if the ECU/TCU has decided to keep the TC locked after hitting the brake. Now I hit the gas, and the computer sees the state is currently TC locked, low engine RPM, higher gear than required for acceleration -> now is the computer has to unlock the TC and downshift. This may cause the lag??

Fast forward to the update - if the ECU/TCU considers unlocking the TC earlier and downshifting faster after initial braking, the lag would be reduced. However, if you still happen to hit the gas in the initial 'decision' state you would still get some lag (but reduced).

Does that make sense or am I out to lunch here?

 

Its correct, and what I find interesting is that all 3 of the Nissan products Ive driven seem to have a little time where the transmissions "think" about what to do.

Best seen in my Frontier....if Im cruising along on the highway at 60 mph then hit the gas, the RPMs go up about 500, then come back down, THEN the truck will downshift if you have enough throttle open.

The G does this now, after the update. I think what we are seeing is its thinking less....possibly because its been programmed now to require less throttle input before it will actually downshift. This *may* result in worse MPG, since we're going to be at lower gears, higher RPMs than normal. But it DOES translate into better, more correct performance.

 

Yes this seems to be exactly what I observe in certain situations with the G after the update. Maybe it has the advantage of spooling up the TC a bit before shifting and causing more of an 'oomph' and boost when the downshift does happen.

 

Here's the website that I'm checking on daily (if you didn't see it listed before) Just click you Year and model (don't add any info to the bottom two boxes) and it'll show current TSBs for our car w/ the latest one being on top of the list. Lets hope the TSB shows up soon for us sorryas$ 09 owners
Infiniti Publications

 

Ok I don't mean to sound like an idiot but after putting about 500 miles on the car since last week, today I felt lag in dofferent cercomstances. First when I came to a red light, right before I can come to a complete stop, the light turned green, I let go of the brake and pressed gas and that's where I felt about a 1-1.5 second of lag and then the car took off like a rocket.
Another time in the same street when I was making a right turn, I was coming to a slower speed from 45mph to about 10mph and made the turn whiling going 10mph and then I pressed the gas and felt the lag yet again. Both occasions in less than 15 minutes. I'll drive a little more and see if it happens again or just one time mistake.

 

Had new TSB done today, while car in the shop, had a 2012 loaner (first time, previous had 2010 or 2011 loaners). The 2012 was very responsive. When I asked the dealer if the flash will make my 2011 drive like a 2012 the response was...Infiniti will not state that after reprogramming your car, it will drive like a 2012..... Driving my car back home with the TSB, better than before but far short of the 2012. This suggests aside from programming changes, there were likely hardware changes in the 2012 absent in older models. Will give it some more run time, but bottom line, while this TSB is an improvement, the software alone does not account for the initial 7AT design flaws.