G37 7speed transmission reprogram
11-30-2011, 11:36 PM
#766
Registered User
Join Date: May 2010
Location: Long Island, NY
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
Had my 2010 G37xS serviced today. My dealer informed me that the most recent update for the transmission was already performed on my car in August. I still have my delayed 1-2 and 2-3 upshifts, but it is a touch better. I drove a 2011 G37x loaner - it suffered from the same issue. Getting back into my car was great as it made me realize how much better my 7AT was!
Regarding the different 7AT gearing between the G37 and the G25 and M37, and the suggestion that this could be the source of some problems - I don't think different gearing alone is going to create this problem.
Regarding the car reaching 35 mph in 5th ... this is only a function of the transmission gears and the rear-end ratio together. The M37 also reaches 35 in 5th. I think the cars are geared this way because of the 3.7's torque - it does have torque, and that's the only way cars of this weight can pull at just 1,500 rpm. I know many members believe the 3.7 does not have low-end torque, but it does ...
I think the 7AT in the G37 limits the torque in gears 1-3. I believe the torque converter is not fully locking up until 4th gear, which would explain a number of things: the resistance I feel upon take-off being the first! It would also explain the slow, delayed shifts - if the M37 7AT is locking up sooner, then its crisper and quicker shifts make sense. A supporting point is that my 3-4 upshifts are always crisp and quick (and why the M37 feels SOOOOO much torquier and is more enjoyable to drive around town).
The torque converter not fully locking up in gears 1-3 could also explain the infamous "lagging" - follow me on this: driving at 40 mph then you slow down a little (deceleration from 40-30 could result in the 7AT downshifting from 6th or 7th down to 4th), then upon accelerating again, the 7AT would try to grab 3rd and face needing the torque converter to now unlock enough to downshift from 4th to 3rd resulting in the delay or lag in, what we have mostly indicated as selecting a gear. This could also happen with deceleration to an even slower speed, as another member posted in a recent test drive.
The notion that the 7AT in the G37 is locking up sooner could also point to the 3-4 flaring, too. Two points on this: (1) My 7AT will upshift much sooner when the car is fully warmed up for a long time - it will grab 7th gear under 40 mph sometimes at 1,300 rpm - but only when really warmed-up making me believe that the torque converter lock-up correlates to temperature. The flaring we have all explained here is when the car cools down for just a bit, then upon start-up and acceleration will flare on the 3-4 upshift ... is the 3-4 upshift flare a result of the torque converter not locking-up like it normally might as a result of the decreased temperature from cool-down? Just a theory ... trying to put the pieces together ...
Lastly, I love the fact that the 7AT in the M37x will grab higher gears quicker. My G37xS holds gears way too long IMO based on throttle inputs - something I've complained about in other posts.
Regarding the different 7AT gearing between the G37 and the G25 and M37, and the suggestion that this could be the source of some problems - I don't think different gearing alone is going to create this problem.
Regarding the car reaching 35 mph in 5th ... this is only a function of the transmission gears and the rear-end ratio together. The M37 also reaches 35 in 5th. I think the cars are geared this way because of the 3.7's torque - it does have torque, and that's the only way cars of this weight can pull at just 1,500 rpm. I know many members believe the 3.7 does not have low-end torque, but it does ...
I think the 7AT in the G37 limits the torque in gears 1-3. I believe the torque converter is not fully locking up until 4th gear, which would explain a number of things: the resistance I feel upon take-off being the first! It would also explain the slow, delayed shifts - if the M37 7AT is locking up sooner, then its crisper and quicker shifts make sense. A supporting point is that my 3-4 upshifts are always crisp and quick (and why the M37 feels SOOOOO much torquier and is more enjoyable to drive around town).
The torque converter not fully locking up in gears 1-3 could also explain the infamous "lagging" - follow me on this: driving at 40 mph then you slow down a little (deceleration from 40-30 could result in the 7AT downshifting from 6th or 7th down to 4th), then upon accelerating again, the 7AT would try to grab 3rd and face needing the torque converter to now unlock enough to downshift from 4th to 3rd resulting in the delay or lag in, what we have mostly indicated as selecting a gear. This could also happen with deceleration to an even slower speed, as another member posted in a recent test drive.
The notion that the 7AT in the G37 is locking up sooner could also point to the 3-4 flaring, too. Two points on this: (1) My 7AT will upshift much sooner when the car is fully warmed up for a long time - it will grab 7th gear under 40 mph sometimes at 1,300 rpm - but only when really warmed-up making me believe that the torque converter lock-up correlates to temperature. The flaring we have all explained here is when the car cools down for just a bit, then upon start-up and acceleration will flare on the 3-4 upshift ... is the 3-4 upshift flare a result of the torque converter not locking-up like it normally might as a result of the decreased temperature from cool-down? Just a theory ... trying to put the pieces together ...
Lastly, I love the fact that the 7AT in the M37x will grab higher gears quicker. My G37xS holds gears way too long IMO based on throttle inputs - something I've complained about in other posts.
12-08-2011, 09:56 PM
#767
Registered User
Join Date: Sep 2004
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
So I'm not sure but it seems the colder weather is making my car do the herky jerky much more now than in the summer/early fall. Temps have been getting into the 30-40's in MA lately and I definitely notice the transmission jerkiness issue more.
Just curious, does anyone reset the ECU regularly? I found when I reset it I would be fine for 2-3 weeks before the transmission started "acting" up again. Probably not going to be good for MPG but at least I don't feel like I'm going to slam into someone on the highway in stop/go traffic.
Just curious, does anyone reset the ECU regularly? I found when I reset it I would be fine for 2-3 weeks before the transmission started "acting" up again. Probably not going to be good for MPG but at least I don't feel like I'm going to slam into someone on the highway in stop/go traffic.
12-12-2011, 10:52 PM
#769
Registered User
Join Date: Dec 2011
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
The reprogram worked great. I had it done to my 2009-G37x a couple of weeks ago (Nov. 2011). The sluggishness is completely gone and the shifts are much crisper. It also fixed all of the following issues (taken from the service bulletin):
ECU Reprogram (Transmission Erratic shifting and hard down shifting)/ Service Bulletin
Service Bulletin Number: 311145. Summary:Any of these incorrect gear ratio DTCs stored: P0732, P0733, P0734, P0735, P0729, and/or P1734.
and/or
A slight vehicle vibration/shutter with light acceleration at low speeds,
and/or
At times, the engine rpm goes up (about 200 to 250 rpm) during the 3rd > 4th up shift, or the 4th > 5th up shift,
and/or
Engine braking feel is more than expected with deceleration,
and/or
The 2nd > 1st down shift is harsher than expected.Service Bulletin 184968
Summary: Infiniti: affected vehicles has a harsh 4-3 downshift while coasting at 30-20mph, with closed throttle condition. Engine braking may also be felt under same driving conditions.
ECU Reprogram (Transmission Erratic shifting and hard down shifting)/ Service Bulletin
Service Bulletin Number: 311145. Summary:Any of these incorrect gear ratio DTCs stored: P0732, P0733, P0734, P0735, P0729, and/or P1734.
and/or
A slight vehicle vibration/shutter with light acceleration at low speeds,
and/or
At times, the engine rpm goes up (about 200 to 250 rpm) during the 3rd > 4th up shift, or the 4th > 5th up shift,
and/or
Engine braking feel is more than expected with deceleration,
and/or
The 2nd > 1st down shift is harsher than expected.Service Bulletin 184968
Summary: Infiniti: affected vehicles has a harsh 4-3 downshift while coasting at 30-20mph, with closed throttle condition. Engine braking may also be felt under same driving conditions.
Last edited by toddgeisler; 12-12-2011 at 10:59 PM. Reason: more info
12-12-2011, 11:02 PM
#770
is this the ITB10-075?
The reprogram worked great. I had it done to my 2009-G37x a couple of weeks ago (Nov. 2011). The sluggishness is completely gone and the shifts are much crisper. It also fixed all of the following issues (taken from the service bulletin):
ECU Reprogram (Transmission Erratic shifting and hard down shifting)/ Service Bulletin
Service Bulletin Number: 311145. Summary:Any of these incorrect gear ratio DTCs stored: P0732, P0733, P0734, P0735, P0729, and/or P1734.
and/or
A slight vehicle vibration/shutter with light acceleration at low speeds,
and/or
At times, the engine rpm goes up (about 200 to 250 rpm) during the 3rd > 4th up shift, or the 4th > 5th up shift,
and/or
Engine braking feel is more than expected with deceleration,
and/or
The 2nd > 1st down shift is harsher than expected.Service Bulletin 184968
Summary: Infiniti: affected vehicles has a harsh 4-3 downshift while coasting at 30-20mph, with closed throttle condition. Engine braking may also be felt under same driving conditions.
ECU Reprogram (Transmission Erratic shifting and hard down shifting)/ Service Bulletin
Service Bulletin Number: 311145. Summary:Any of these incorrect gear ratio DTCs stored: P0732, P0733, P0734, P0735, P0729, and/or P1734.
and/or
A slight vehicle vibration/shutter with light acceleration at low speeds,
and/or
At times, the engine rpm goes up (about 200 to 250 rpm) during the 3rd > 4th up shift, or the 4th > 5th up shift,
and/or
Engine braking feel is more than expected with deceleration,
and/or
The 2nd > 1st down shift is harsher than expected.Service Bulletin 184968
Summary: Infiniti: affected vehicles has a harsh 4-3 downshift while coasting at 30-20mph, with closed throttle condition. Engine braking may also be felt under same driving conditions.
12-13-2011, 11:44 AM
#772
Registered User
Join Date: Feb 2011
Posts: 163
Likes: 0
Received 0 Likes
on
0 Posts
It's fun to read through this after having my car for awhile now. I seriously hate the 7AT.
I've got 10,300 miles on my 2011 G now, and the transmission is still crap. I pretty much always drive it in manual mode, because the transmission is stupid and never knows what the hell it is doing. Put it in DS, and it never drives as aggressively as I'd like it to, or I'm just cruising down the freeway, and suddenly it'll downshift to 4th when I give it just a little bit of gas, then it hangs in gear forever. It's never ready to give me power I need within a second, and when I don't want it, there it is. It takes at least 3 seconds in 7th gear from the time I floor it, to the time full power is applied. Sometimes it shifts down farther than I want it to... it's hard to hit the gear you want for the power you're looking for.
The other big one that drives me nuts is the 4-3 downshift. I drive a very predictable route to work every day, and I have a corner where I am going about 25mph, and there's no reason to use the brake. I will sometimes enter this corner >25mph, and the car is in 4th gear. At turn apex, I give it gas, and the car feels like it's stalled... 2-3 seconds of no gas and it finally springs to life... you can tell it's the transmission shifting. If I'm on top of it with the paddles, I can overcome it. But it's like the transmission gets stuck in the downshift and waits to apply power until the shift is complete. It's the strangest thing.
Then there's the 2nd gear torque converter release point... the point at which the car slows enough to have to release the torque converter, but not quite enough to have to shift down into first. I will come into a slightly aggressive stop in 2nd gear, and then start to let up on the brake nearing the end of the stop, and the release of the torque converter happens too late and causes the car to jump forward slightly, creating the sensation of not braking enough (ready to hit the car in front of you), causing you to want to brake harder, making it near impossible to make a complete stop without modulation of the brake pedal in some fashion.
In Manual mode, coming to a stop is painful... You always have to change brake pressure, and downshifts are extremely noticeable when done automatically. Something that doesn't happen in regular D mode, or even DS. I find in many cases, for the smoothest stop, I just drop the car in Neutral. So, basically, I have a manual without a clutch pedal. I also wish you could get back into DS from manual mode by holding the + paddle.
Then there's the 3-4 flare, which I can often replicate by being in manual mode in 3rd, and accelerating just a little bit, then shifting to 4th... Doesn't happen too often, but it's annoying.
The 7AT is great for those times when you want to drive like grandma and get great gas mileage, or drive it like a crazy person, completely out of control. But if you want to drive mildly aggressively, there's just no middle ground in this transmission. Manual mode is the only way to go.
I will complain to Infiniti every time I take the car in... I'll probably even send a threatening letter to Inifiniti. It wouldn't be my first time having to get a manufacturer to listen to and fix a problem with a car. Honestly, to me it feels like a ton of it could be fixed through software.
I've got 10,300 miles on my 2011 G now, and the transmission is still crap. I pretty much always drive it in manual mode, because the transmission is stupid and never knows what the hell it is doing. Put it in DS, and it never drives as aggressively as I'd like it to, or I'm just cruising down the freeway, and suddenly it'll downshift to 4th when I give it just a little bit of gas, then it hangs in gear forever. It's never ready to give me power I need within a second, and when I don't want it, there it is. It takes at least 3 seconds in 7th gear from the time I floor it, to the time full power is applied. Sometimes it shifts down farther than I want it to... it's hard to hit the gear you want for the power you're looking for.
The other big one that drives me nuts is the 4-3 downshift. I drive a very predictable route to work every day, and I have a corner where I am going about 25mph, and there's no reason to use the brake. I will sometimes enter this corner >25mph, and the car is in 4th gear. At turn apex, I give it gas, and the car feels like it's stalled... 2-3 seconds of no gas and it finally springs to life... you can tell it's the transmission shifting. If I'm on top of it with the paddles, I can overcome it. But it's like the transmission gets stuck in the downshift and waits to apply power until the shift is complete. It's the strangest thing.
Then there's the 2nd gear torque converter release point... the point at which the car slows enough to have to release the torque converter, but not quite enough to have to shift down into first. I will come into a slightly aggressive stop in 2nd gear, and then start to let up on the brake nearing the end of the stop, and the release of the torque converter happens too late and causes the car to jump forward slightly, creating the sensation of not braking enough (ready to hit the car in front of you), causing you to want to brake harder, making it near impossible to make a complete stop without modulation of the brake pedal in some fashion.
In Manual mode, coming to a stop is painful... You always have to change brake pressure, and downshifts are extremely noticeable when done automatically. Something that doesn't happen in regular D mode, or even DS. I find in many cases, for the smoothest stop, I just drop the car in Neutral. So, basically, I have a manual without a clutch pedal. I also wish you could get back into DS from manual mode by holding the + paddle.
Then there's the 3-4 flare, which I can often replicate by being in manual mode in 3rd, and accelerating just a little bit, then shifting to 4th... Doesn't happen too often, but it's annoying.
The 7AT is great for those times when you want to drive like grandma and get great gas mileage, or drive it like a crazy person, completely out of control. But if you want to drive mildly aggressively, there's just no middle ground in this transmission. Manual mode is the only way to go.
I will complain to Infiniti every time I take the car in... I'll probably even send a threatening letter to Inifiniti. It wouldn't be my first time having to get a manufacturer to listen to and fix a problem with a car. Honestly, to me it feels like a ton of it could be fixed through software.
12-13-2011, 12:27 PM
#773
Agree with your post completely.
I have noticed too, usually on highway. If someone slow cuts you off and you want to go around them, so you give a lot of gas, it will downshift so much that the rpm is in the 6500+ range. Then it has to upshift again at 7600. I know this can solved by controling the gas, but ideally I would want the rpm in the 4000-5000 range.
The other issue with 6500+ rpm is that it feels like that someone just kicked you in the back.
The other issue with 6500+ rpm is that it feels like that someone just kicked you in the back.
12-13-2011, 02:37 PM
#774
Registered Member
Join Date: May 2005
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
Its been a long time since I've been on the forum. I had a 2005, 2008, and now a 2011 all G35x/G37x.
My 2008 G35X tranny was great. Not a single issue with it. I have 3000 miles on my 2011 G37x and took it for its first oil change. I asked my dealer to look at the tranny because I experience harsh downshifts from 2nd to 1st when coming to a complete stop. You can actually hear/feel the tranny "THUNK" into 1st gear and it throws you forward. My wife thought I did something and told her the car did it downshifting.
I have also noticed lag when on the highway and romping on the gas.
Anyway the dealer said they didn't find anything with the tranny and if it only did it when cold/first running I could leave the car there and they can test drive it in the morning. I told them the loaner car which had been sitting in the garage also did the exact same thing when coming to a stop light.
I never ever bothered to look into issues before getting the 2011 as my 2008 was near perfect. I guess I know better now. I'm glad I lease them because the car won't be staying after the lease is over.... in another 3 years.
I also sent an email to the service manager to let him know I looked for "tranny issues" on the net and wanted to know if the service bullitin had been applied to my car. I'll have to wait and see what he says.
My 2008 G35X tranny was great. Not a single issue with it. I have 3000 miles on my 2011 G37x and took it for its first oil change. I asked my dealer to look at the tranny because I experience harsh downshifts from 2nd to 1st when coming to a complete stop. You can actually hear/feel the tranny "THUNK" into 1st gear and it throws you forward. My wife thought I did something and told her the car did it downshifting.
I have also noticed lag when on the highway and romping on the gas.
Anyway the dealer said they didn't find anything with the tranny and if it only did it when cold/first running I could leave the car there and they can test drive it in the morning. I told them the loaner car which had been sitting in the garage also did the exact same thing when coming to a stop light.
I never ever bothered to look into issues before getting the 2011 as my 2008 was near perfect. I guess I know better now. I'm glad I lease them because the car won't be staying after the lease is over.... in another 3 years.
I also sent an email to the service manager to let him know I looked for "tranny issues" on the net and wanted to know if the service bullitin had been applied to my car. I'll have to wait and see what he says.
12-13-2011, 03:57 PM
#776
Registered User
Its been a long time since I've been on the forum. I had a 2005, 2008, and now a 2011 all G35x/G37x.
My 2008 G35X tranny was great. Not a single issue with it. I have 3000 miles on my 2011 G37x and took it for its first oil change. I asked my dealer to look at the tranny because I experience harsh downshifts from 2nd to 1st when coming to a complete stop. You can actually hear/feel the tranny "THUNK" into 1st gear and it throws you forward. My wife thought I did something and told her the car did it downshifting.
I have also noticed lag when on the highway and romping on the gas.
Anyway the dealer said they didn't find anything with the tranny and if it only did it when cold/first running I could leave the car there and they can test drive it in the morning. I told them the loaner car which had been sitting in the garage also did the exact same thing when coming to a stop light.
I never ever bothered to look into issues before getting the 2011 as my 2008 was near perfect. I guess I know better now. I'm glad I lease them because the car won't be staying after the lease is over.... in another 3 years.
I also sent an email to the service manager to let him know I looked for "tranny issues" on the net and wanted to know if the service bullitin had been applied to my car. I'll have to wait and see what he says.
My 2008 G35X tranny was great. Not a single issue with it. I have 3000 miles on my 2011 G37x and took it for its first oil change. I asked my dealer to look at the tranny because I experience harsh downshifts from 2nd to 1st when coming to a complete stop. You can actually hear/feel the tranny "THUNK" into 1st gear and it throws you forward. My wife thought I did something and told her the car did it downshifting.
I have also noticed lag when on the highway and romping on the gas.
Anyway the dealer said they didn't find anything with the tranny and if it only did it when cold/first running I could leave the car there and they can test drive it in the morning. I told them the loaner car which had been sitting in the garage also did the exact same thing when coming to a stop light.
I never ever bothered to look into issues before getting the 2011 as my 2008 was near perfect. I guess I know better now. I'm glad I lease them because the car won't be staying after the lease is over.... in another 3 years.
I also sent an email to the service manager to let him know I looked for "tranny issues" on the net and wanted to know if the service bullitin had been applied to my car. I'll have to wait and see what he says.
Lets's see how it goes with the engineer....There is no real FIX out there as far as i know..only BS. Too bad, they should have left the 5AT alone.
12-13-2011, 04:32 PM
#777
My 07 w/ 5AT was a better car to drive "mildly agressive" like member bitNine's post above detailed so well. The 5AT always seemed to be in the right gear and in the sweet spot of the torque curve. The 7AT is pretty good accelerating up through the gears but slower deceleration it starts hunting and just cruising in town at speeds from 25-40 the 7speed gets clunky at seems to be guessing incorrectly where the sweet spot should be. I agree w/ many posters that this should be a mapping fix not a mechanical issue. The trans seems solid and can shift pretty quick, it's just the extra "thinking" it's always doing that causes so much of the complaints IMO.
12-13-2011, 05:42 PM
#778
Registered User
Join Date: Jan 2011
Posts: 42
Likes: 0
Received 0 Likes
on
0 Posts
I got the exact same issues at bitNine... I also drive Manual Mode everytime and the jerkiness from downshifting automatically when coming to a stop is ridiculous. Sometimes I even hear a clunk..
I think I may start putting it into neutral too when it gets bad haha...
but is there any negative effect by switching into netural than back to ds manual mode?
I think I may start putting it into neutral too when it gets bad haha...
but is there any negative effect by switching into netural than back to ds manual mode?
12-13-2011, 11:50 PM
#779
Registered User
And I agree it can likely be fixed with software.
I wonder if this "learning" transmission/ECU is the culprit. I wish it would settle on a mode and stay there. I drive in all sorts of ways all the time, sometimes slow, sometimes full-out. I can imagine it's confused.
12-14-2011, 03:06 AM
#780
Great write-up and I have experienced most all that at one point or another.
And I agree it can likely be fixed with software.
I wonder if this "learning" transmission/ECU is the culprit. I wish it would settle on a mode and stay there. I drive in all sorts of ways all the time, sometimes slow, sometimes full-out. I can imagine it's confused.
And I agree it can likely be fixed with software.
I wonder if this "learning" transmission/ECU is the culprit. I wish it would settle on a mode and stay there. I drive in all sorts of ways all the time, sometimes slow, sometimes full-out. I can imagine it's confused.
I feel it is... it's a retarded feature...
D casual driving
DS sport driving
that's all they needed to do. I spend more time in manual than i really should.. but it's dangerous to not have the power when you need it.