Warp37, You have it right on....I agree with the ECU/ throttle response, but if you go Way, Way Back on this Thread, a member described the issues in "electronic talk"...It also involves the Torque Converter which locks up way way too early. That's why you are in 5th or 6th gear on local roads at 35-40 mph. I don't know about you guys {I probably a lot older than most} but when that TC locks up for better fuel mileage, there is that slight [I]"rumble' like feeling[I].... It feels exactly like an old Auto Tranny when they introduced the 4th or Overdrive gear in cars of old...You are in too high a gear, the RPMs are low (1500 or so), and if you step on the brakes and then on the gas, what hesitation. Not be redundant, (i know I am on this thread), but this scenario varies on different days !!!

 

Writing to add to the vast information about the 7AT experiences provided by other readers, and hoping that Infiniti Corporate is among them. I have tried to catch-up on this thread, but admittedly I haven't caught-up from the last time I read through ...

My experiences and "issues" are actually a bit different from other folks here, but I also have discovered a new perspective from driving my partner's M37x for a few hundred miles.

The "lagging": Yes, I, too, experience the lagging - driving, slow down a little, then step on the gas again to experience a delay in the transmission catching the next gear. In fact one time in the middle of traffic, I experienced the "lag" for more than 3 FULL seconds (this is not an exaggeration - really!). But it is not as common for me as with other readers; it is most frequent after a good romp with the car in full manual mode, and then returning to D Mode.

Driving in DS Mode is not helpful. DS Mode is actually nearly identical to D Mode for me, except under hard braking or hard acceleration while cruising that keeps the 7AT in a much lower gear unnecessarily. In DS Mode, the 7AT also lugs around in a higher gear, and is very, very reluctant to downshifting with throttle inputs; D Mode is better. As a result, I frequently use the paddle shifters (I normally drive rather enthusiastically). The only time I have recently enjoyed DS Mode is when I had 3 passengers.

My different 7AT issues ... the 1-2 and 2-3 upshifts under moderate acceleration (shift points between 2,700 and 3,100 rpm) are ridiculously lazy, slow, and delayed - it will "shift" out of gear, but then you can see the tach needle slowly drop until the next gear is engaged - as an avid auto enthusiast who craves a quick auto gear change, and previous owner of a 2008 G35xS - it's an absolutely infuriating experience. I can avoid this by stepping on the throttle more or quickly easing into the throttle so that the 1-2 and 2-3 shift points occur at or above 3,200 rpm - but why should I have to drive quicker than I need or want to? At lighter acceleration (shift points < 2,500 rpm), the shifts are fine. It's making me hate the car and is ruining my experience. Overall, the shifts of the 7AT are not as quick as those on my 2008 G35xS, and that is a major disappointment.

I had written in a previous post that the problem with the lazy 1-2 and 2-3 shifts could be remedied by driving in DS Mode - that is no longer the case and hasn't been since about 2 weeks after getting my car back from the dealer on the last oil change (I think August 2011).

To make matters worse, I have a new problem: Now under WOT, the 7AT hangs onto 1st and 2nd gears instead of quickly shifting like it used to. Terrible. TERR-I-BLE!

I have been driving my partner's 2011 M37x for a few hundred miles now, and I am stunned by the difference in the performance of the transmission - very, very quick shifts; no lagging; no hesitation; quick to downshift under throttle - it's just ... great! I do know from some quick online research that the 7AT gear ratios in the G37 are different than those in the M37 (in the M37, 1st and 2nd are not as short, and there is a greater gap between 1st and 2nd). But I can't imagine that those differences alone can make such a difference. Based on how the M drives, and without in-depth knowledge of transmissions, I believe this could just be a difference in transmission torque converter calibration or ECU - maybe!

I don't know why the M37x 7AT is so much better ... but it is. It does demonstrate that the 7AT can be great, but I am not sure what is making them different. I am driving the M this week to avoid my G's 7AT.

@ Almatti - I can't believe after a year and a half you're still at it - good for you. The sqeaky wheel does get the oil!!

Sorry for the super-long post, but I am hoping that this information would be helpful - especially to Infiniti Corporate (we all know you're reading this anyway!).

 

I just wanted to share my experiences after test driving a new 2012 G37 Journey (no sports package). The Journey sedan I drove had the two drive modes discussed in this thread (Drive and Drive Sport). Area of test drive was in the Bay Area, California on 3 kinds of roads: Residential, commerical-main throughfare (i.e. 2-3 lanes in each direction), and freeway (4 lanes in each direction). Temperature was approximately 65 degrees.

This was my second test drive at a different dealership for the sole purpose of the automatic transmission problem that many have experienced.

Downshifts
I did not experience any hard or abrupt downshifts. I attempted to duplicate the problem by both coasting the car (no gas and no brake) and also at other times, continuous pressure on the brake pedal.

Lags
As for the lag, I could not duplicate it. On the freeway, I slowed down to 20-30 mph (no vehicles were behind me in my lane so I could safely do so). The method of slowing down was to first brake, then release the brake and coast (no gas). Then I pressed the gas. The car responded immediately and with enough power for me to make a lane change. For frame of reference, it responded instantly enough to go back to 45-50 mph. I mention the speed to give an idea of how much and hard I pressed on the gas pedal. I repeated this when I weaved in and out of traffic to get over several lanes to exit the freeway.

In residential streets, I did not experience any lag. In an attempt to get on the on ramp to the freeway, I weaved in and out of traffic (20-35 mph) to get over several lanes. This involved accelerating, passing, merging, braking, then accelerating again. Response was instant.

There was only one situation where I experenced a lag. The lag was 1 second. Situation was making a U-turn on commerical throughfare road. As I approached the intersection in the left lane, I pressed the brake pedal continously as the light was RED. But the signal light suddenly turned GREEN. Seeing this, I released the brake pedal and coasted down to 5-10 mph. I then turned left to make the u-turn. As I was coming out of the turn, I pressed on the gas to accelerate. That was when the lag occured. By lag I mean I did not feel the car respond immediately by instantly accelerating in the span of 1 second. So my foot instinctively applied more gas. The engine revved up accordingly and accelerated. The car did not jerk because I did not apply much more pressure.

I know this was not the perfect test. As for flares, I was not specifically looking for them (checking traffic and talking to sales associate). But I did the best I could and I wanted to share the results. I tried to be as objective as possible for any one interested in 2012 G37 vehicles.

If you are interested in the 2012, go and test drive it with your own driving habits. The sales associate allowed me to test drive the vehicle for half an hour.

 

Being that it's a learning transmission, is a half hour (10-15 miles?) really enough to have it adapt to your driving habits. I would think most people test driving cars drive them relatively aggressively, so it learns a more aggressive drive pattern.

See if they let you take it for an all day test drive.

 

This.

In fact even an all day test drive may not tell the story. The lag on mine didnt show up until about 1K miles on the car. The first 500 were a 90% highway trip from VA to CT, and it performed perfectly....then again, there wasnt much shifting to be done.

I *do* think, however, that its possible the tranny does start to get better again at some point. My car has 3600 miles on it, and I notice it being more predictable, especially in regards to the "slow down then try to speed up" lag. Yes I have to press the pedal more than Im used to, but lately I havent been experiencing a jolting 5th to 2nd downshift....rather its a more gradual 5, 4, 3, or if necessary a 5 to 3 downshift.

I still say most of the problems are caused by software, and hopefully Infiniti is working to remedy them. I did NOT know that the M has different gearing, but that could also explain the lack of lag......the 3.7L engine and its kind-of-lacking low end is probably messing something up with the "universal"ness of the 7AT. It works OK in the M with the same engine simply because the powerband is changed with the different gearing. It almost seems like Nissan is trying to make a square peg (7AT) fit in a square hole (M), round hole (G), and who knows what other shape holes. Im sure it saves them $$$ having one transmission across multiple vehicles, but it might take some time to get it just right where it works as well in the square hole as it does in the round hole.

 

The last four posts are really informative. Yes, LINY_ROB, I'm still AT IT !!!

I feel I'm spending a pretty penny and I want Complete Satisfaction. Not half-assed performance because Infiniti needs to meet Fleet US Gpv't mileage requirements. With 23k miles on my car, I still get the Lagging....As LINY says: TERRIBLE...

I just went o look at a Volvo S80 T6. Didn't drive it, although I did recently drive a XC70 2012 Vovo wagon from Enterprise as a loaner for another car's repairs. The Vovo was super quiet, much less hesitant, of course, not the power (non-Turbo) as the G, but a very very nice car. It's not a Performance Sport Sedan, It's a Wagon. I did not like the new S80, as far as the exterior look is concerned. Interior is terrific. The Wagon had a 6 speed Auto tranny, silky smooth..

If a test drive, a good long one of the new M37X should reveal what has been posted, I may opt to go that route: Only if I cn turn in the car without any further costs.

 

Rob, my car does the exact same thing with the 1-2 2-3 shifts. Our trannys are not borken......they aren't slipping b/c they're bad...its all the programing. You're right....give the car a bit more throttle that is needed to give a 3K rpm shift (so say 3500) and it sharpens right up. Maybe its becuase I drive like a grandma most of the time...so it has adopted to my style? I dunno...

Happy to hear I'm not alone. Now the G25 loaner I had shifting much quicker...but is tha becuase of better programing? different leanring curve (people drive harder), or the fact that the 25 has so much less torque to deal with.

I think I'm going to bring it back to make sure it has the latest flash (both tcu AND ecu).

 

I wish we could come up with a mod to reset the tranny ECU each time the engine is started.

 

Glad to know I'm not alone!! Thanks!!

FYI - the G25 has the same 7AT gearing as the M37, with the G25, G37, and M37 all sharing the same rear-end ratio, too.

I drive in a wide variety of styles each time I drive ... so my personal conclusion is that the adaptive transmission programming is not effective ... at least in the G37x.

My G37xS goes in for service tomorrow ... I have clearly delineated my problems - here's hoping for the best!

P.S. Today I spent another day with the M37x ... 7AT is still great!

 

Its gotta be a gearing thing then....the only problem with that is thats a physical mechanical thing that Infinti would probably never fix on the G37 (at least not for already-sold cars). The only other option is tuning it out with s/w.

But I have to wonder WHY the gearing difference, does it make the car that much sportier? Trying to keep the powerband towards the upper "sporty" RPMs vs lower "touring" style RPMs like the M and G25?

 

I double-checked the gearing listed in Infiniti's spec sheets for the 2012 cars and the G37's 7AT has more aggressive gearing than what is used in the G25, at least in the first 4 gears.

G37
4.923 3.193 2.042 1.411 1.000 0.862 0.771 final: 3.357

G25/M37
4.783 3.102 1.984 1.371 1.000 0.870 0.775 final: 3.357

 

Are the earlier years (10, 11) the same as the 12 G?

I know someone thought their '12 loaner G worked better, but it was so new at the time it could just be because it hasnt "adapted" yet. Also pretty sure BlackBetty mentioned there were no mechanical changes in the '12 7AT for the G, which leaves only a possible s/w update as the reason for the '12 shifting better (if it indeed does still shift better, even after adapting).

Since it seems to work OK in the M, it has to be the more aggressive gearing, probably putting the RPMs at just the right spot for the computer to be confused, or to think it needs to shift because it doesnt know its in the "more aggressive" vehicle and it SHOULDNT shift.

Do the G25 and M37 hold lower gears better? Its almost like the aggressive gearing in the G is making the car reach an RPM shift point earlier, regardless of the speed the car is at....that would explain the whole 5th gear at 35 mph thing. Lower gearing would leave the G25 and M37 in lower gears longer.

 

I just had my 12 G37xs Sedan in to the dealer to install a clear bra (I have reasons for a dealer install)…The car they gave me overnight and the full next day was an 11 x coupe with only 1800 miles on it.

Well being me I left work early to have some fun in the coupe. The car was, well…terrible.

The lag on the quick stop starts was there on almost every stop and the downshifts in DS mode stayed there overly long even on a straight line run. The car felt sluggish overall and the suspension was soft. I put 188 miles on the car and will tell you that’s not long enough to teach it….

If I test drove this loaner coupe I would not have bought the G. I only have 600 miles on my Sedan and it was great to get back into it. Let’s hope..I hope my car stays just as it is.

 

s this for the rough down shift issue? I thought there was a TSB on that a year back already?

 

Keep in mind it likely had regular gas in it, unless you filled it up. I know our trannies have issues... but the gas could be a cause.