g37Frost

Hi everyone,

First post here, I'm a brand new owner of a graphite shadow 2012 G37 sedan (base) that I just about fell in love with the moment I took it on its first test drive. One owner, very well maintained, interior is immaculate even after 48,000 miles. There's one thing that concerns me though.

I've been searching the forums here and researching this 'throttle lag' that a lot of people are dealing with. My G does not manifest any such lag during normal driving conditions. However, since taking it home, I've noticed something similar when the car has been at rest overnight and I am first driving it out of the neighborhood to work in the mornings. When the car is stopped and I am turning onto a main road—the car's first real acceleration of the day—there is a distinct 1-1.5 second lag between the time I press the pedal down and the transmission engaging, resulting in a sudden lurch forward with a squeal of the tires. After the engine warms up a bit, this goes away and the car shifts normally. Leaving the engine off for 4-5 hours is not enough to bring back the lag; leaving it overnight does, though.

I spoke to a service guy at my local Nissan dealership (we don't have an Infiniti dealership within a 2-hour radius of where I live, so I haven't been able to consult with one yet), and described the issue to him. He said this is not uncommon in Gs, something to do with the transmission fluid needing a little time to circulate the system, and that I should not worry about it.

Sooooo.... do you think he's right? Or should I try to reset my ECU, or investigate a firmware update? Has anyone else encountered this?

Ricio1991

Well there is two software transmission updates, you have to make sure they both are done, helps a bit but sometimes there still lag but it does help I just got my second update after i bought my car and it helped

g37Frost

Took the car to the Infiniti dealership. They reprogrammed the ECU, and noted on my report that this was a known issue that reprogramming the ECU would fix. Fortunately the car is still under warranty so they didn't charge me for doing it.

Here is the actual language on my service report:
Problem seems to be gone now. Three mornings since getting it back from the dealer and there's been no lag at all.

Thanks for your help, Ricio.

Ricio1991

Glad it worked out and your welcome

g37Frost

UPDATE: the throttle lag has returned. It still only seems to be evident when the car has been resting overnight, at least 6-7 hours. When I want to give it a good, firm acceleration, the engine revs but no power is sent to the wheels right away. When they finally do, there is a sudden lurch forward accompanied by a peal of sound from the tires.

This morning something unusual happened: I was stopped at a 4-way and when it was my turn, I pressed on the gas... a little harder than I needed, but I wanted to see what the car would do. The engine revved, but instead of a pause-then-lurch, the car eased into the intersection and the traction control light blinked at me a couple times. It seems the TC kicked in to keep the built-up torque from spinning the wheels over the concrete (and making a lot of noise).

This problem does not manifest at all after driving for 2-3 minutes. It accelerates with gusto when asked. It's as if it's a little sleepy fresh out of the barn.

chuckie311

iTrader: (3)

try doing this

g37Frost

In case it matters to anyone, I finally found (and fixed) the problem in my G37 with the "throttle lag".

As it happens, none of the previous attempts to fix it worked. I realized that what the car was doing was slipping out of gear. As I stopped at a stop sign or wherever, it was falling into neutral, and then was a little late reengaging 1st when I stepped on the gas. When it did shift, I was already pressing down on the gas pedal so the car popped into gear and lurched forward.

Changing the transmission fluid did the trick. I had them completely replace the fluid, and the problem went away immediately. It's been four weeks now since that was done, and the problem has not reappeared. So I think it's safe to say that it's been fixed.

Hope this helps someone who might be grasping at straws trying to find a solution to this problem. I can tell you it's been a joy having a perfectly driving G.

si_driver

That is odd that they even did any updated at the dealer. I just had the car at the dealership this week about the transmission, also with a 2012. Was told there were absolutely not software updates available for the 2012. Another person on this board was told the same this week also.

But the transmission fluid change sounds interesting. I am at 51,000 right now. May consider doing it too. I don't have such a delay when the engine is cold but the car just doesn't drives as smooth as it should.

May wait until spring to do it....

Ricio1991

No problem glad it worked out!

Kb Cool

I wonder if the tranny fluid was just low? I really hate the fact the engineers failed to give our cars a dipstick!!

g37Frost

My car just turned 52,000. Changing the transmission fluid also took care of some occasional harsh thumps while the car was stopped and idling, like the gearbox was fidgeting with the gears while not moving. That went away also. The service cost about $300 at my local Nissan dealer but it was worth every cent to me.

Mogcell Pbm

Just to be clear,you guys got a transmission fluid change not a flush right? I've been told by multiple mechanics and nissan that a tranny flush can mess up the transmission. Not sure about the differences between a tranny flush and a change. Anyways is a tranny fluid change covered under warranty?

g37Frost

No, it was not covered under warranty.

I went into my Nissan dealership and asked that my transmission fluid be changed. What was on my bill was a "transmission flush" which I assumed included new fluid. I will check my bill again to make sure. What I do know is that the car is running a lot better now than before, and that was after all the 50K maintenance work that I paid in excess of $700 for at the Infiniti dealership (which obviously did not include a transmission flush).

Not that it matters, but Infiniti had my car for over a week trying to figure out what was wrong with it. (I was driving their Q50 loaner for that time... a fantastic car, by the way, but not nearly as fun to drive as the G.) One of the things they did as part of the 50K maintenance was they cleaned out the throttle bodies, which they were confident would take care of the problem. Sadly, they were wrong and the problem came back right away.

The reason I took the car to Nissan for the transmission change is the Infiniti dealership is 2 hours away, and I was hoping the problem would be discovered to be addressable by the warranty. Changing the transmission fluid was going to be my last-ditch effort before looking for a new G. I was very happy to get a smooth driving car back once that was done.

EDIT:
Here's what my service summary says:

So it would appear they put in 16 quarts of "ATF SYN" which I assume stands for synthetic transmission fluid into my car.

botlfed98

iTrader: (11)

I thought these ECUs are in a different mode under start up conditions. I know my car takes a little warming up before it gives me full power

dbeachy1

iTrader: (1)

I realize this is an old thread, but I wanted to chime in here with what happened in my case. I had the exact same symptoms mentioned earlier in the thread here, which were:

It happened twice for me a few days apart. However, I realized that both times that it happened were right after I took my car off my battery tender (a trickle charger) from being connected overnight and drove it right away. It has never done it before or since and I haven't used the battery tender before or since, so (in my case at least) perhaps the computer got confused by the abrupt drop in battery voltage (my battery tender floats at 13.5 volts) and it took a few minutes for the rolling average battery voltage to reset? i.e., perhaps the computer assumed it was still getting 13.7 volts at the transmission solonoids vs. the 12.0 volts it actually had, and so the shift times were slower than it expected. Then after a minute the rolling average came down to 12.0 volts and everything was fine.

Anyway, that's just a theory, but it did it both times I removed the battery tender and drove it right away, and it hasn't done it before or since.