I'm looking to get a used 10 g37x, and was curious from all the threads I've read about the trans problems ,have they finally fixed the lag/hesitation with any new updates?

 

There is no "fix". There are updates that help the "issue". I'll honestly say that during the colder months, my trans shifts a lot better than the warmer months. With that said, this is the exact reason why I'm changing all the fluids and installing a Stillen trans cooler I picked up for a slick deal over black Friday. Should help keep the fluid a bit cooler during the summer months.

Will report back how the fluid change feels. After that, I'll be getting a tune to further help the transmission lag issue.

 

I've been fairly happy with my trans since the TSB, ECU reset, cleaning the throttle bodies and,installing a grounding kit. That said I'm looking for a tune to get me th wrest of way and am trying to decide whether to go with an etune or to drive to CT for a dyno tune.
Looking forward to feedback on the Stillen trans cooler, if that seems to help I'll go that route as well.

 

I have a used 2011, and have experienced throttle lag in just one place during my driving- The right turn onto a major road. I slow down, glide through the right turn with no throttle, and when I get on the throttle again there's no response and just sat there for maybe 1 to 2 seconds (gives me a "WTF" feeling every single time) and THEN it kicks me in the rump with this rough downshift.

The car is a lease return, and I guess the lease owner wasn't bugged enough to get this issue fixed. Now I'm kind of wondering whether I should fix it or not............... It just happens over and over again on the same turn (though infrequent and kind of random) that it annoys me...

I'm going to a dealer to get a repair on an unrelated problem, and now I'm trying to make up my mind whether to fix or not fix.

Edit: Just saw that I'm not supposed to call this a "fix"... Substitute the word "fix" with "update"

 

Get it! The difference it made on my car was worth paying for. It was done under warranty, but I would have paid for it. I did not like what the update to DS mode though.

 

Thanks for getting back to me. What happened to your DS mode?

 

Yeah curious what happened to your DS Mode?

 

DS no longer drops into a lower gear when braking as easily as it did or does it hold the lower gear as long as it did before. DS was neutered by the update IMO.

 

In DS mode i really have to be braking hard for it to downshift

 

On second thought... I think I'll just live with that lag. I use DS quite a bit in heavy freeway traffic and it sounds like the reprogram would take away part of the engine braking. I have a bad right ankle, and heavy traffic can literally be a pain without engine braking.

 

I have a 2012 G 37 sedan and had issues with huge lags when accelerating especially from 60 mph.
I had the tsb done and most of the lag is gone. It is like a different car.

 

I'll add my two cents here.

I've owned the G37S for about 4 months coming out of a G35 coupe 6MT. The throttle was, needless to say, frustrating beyond belief. Downshifts were jerky, it never felt like it was in the right gear, and throttle response felt completely disconnected. Finally took it into the dealership this morning and told them what was going on (did not mention the TSB). I had a few other things for them to take care of under warranty, so I grabbed a Q70 as a loaner and went to work. I stopped back in tonight to pick it up, and (I know this is getting cliche) it feels like a COMPLETELY different car. I cannot believe how great it drives now - not a subtle change by any means. Shifts are smoother, downshifts no longer make you wonder if you're going to hit the guy in front of you, and the throttle response feels like they connected a throttle cable. I am completely blown away at how much of an improvement this makes. Why this wasn't the program from the factory is beyond me. For those wondering, my work order states "CK rough on downshift: reprogrammed TCM and ECM" If you haven't had this done, I cannot imagine why you wouldn't want to. Again, this isn't so much of an improvement as it is a complete overhaul of the throttle and transmission. It makes a huge difference.

As a side note, I did not enjoy the Q70. It felt extremely heavy, and handled poorly. Acceleration was fine, but beyond that it is a huge downgrade (with some more cool features) from my newly revived G37S.

 

Does the vehicle need to be of certain age or under warranty to get the TCM reprogrammed and/or is there a fee for this? If have an '09 g37x. I'm definitely experiencing the rough down shifts and would like to get it fixed as I've wondered if I might rear-end someone as you noted. Thanks

 

I'm not certain if there is a model year restriction on it. Even if you're not under warranty, I can't imagine it would be more than $100 to flash it out of warranty anyway. Personally, I'd pay $1000 for it if I had to. The car went from frustrating to drive to very impressive. I've had a permasmile the last couple days. Again, I came from a G35 coupe 6MT, so being happy with an auto says quite a bit.

 

So last month I went to the dealership complaing about some transsmion issues like harsh downshifting and lag. When got the car back the paper work reads ITB10-075A COMPLETE. I have a g37x coupe 2009 that I just bought 2 months ago so I don't know what have been done previously. Also, I read most of the comments here so I know that the ITB10-075A is one of the earliest correction was made by infinite and there is a newer one IT12-027D. The reason why I'm saying that is After the update, the harsh downshifting still exists and couple of days ago and noticed harsh up shifting as well (it is like the car shakes a little when up shifts) which is so annoying. I really don't know what to do I love the car but the transsmion keeps freakin me out what I need to know is does applying ITB10-075A means that the newer ones doesn't apply to my car or should try another dealer?