G37 Downshift not smooth TSB Released!

by **mkt** » Fri Jun 05, 2009 8:26 pm

Hi all,

I'm a new owner to 09 g37 automatic coupe and have a problem with transmission (not sure it it's a problem or just the way the car is designed)

During normal driving mode (D), when i let go of the gas pedal at 40mph, the car would slow down but not at constant rate. The car would first decelerate smoothly, then it feels like it's breaking on its own...decelerate smoothly again...then break on its own again. Everytime it "self break", the rmp goes from 1000 to ~1500rpm. Is this normal? I would expect when I release the gas pedal, the car would decelerate at constant speed instead of jerking several times. Is there a way to fix this issue or it's just the sporty nature of the car

Thanks in advance

by **audtatious** » Fri Jun 05, 2009 9:02 pm

Take it in for service. It should be smooth.

Welcome to NICO!

by **TommyC3** » Sat Jun 06, 2009 2:45 am

My 09 Sedan does the same thing, specifically on the 3rd to 2nd downshift.

by **audtatious** » Sat Jun 06, 2009 9:10 am

Weird.....

Maybe I just have not noticed it as I'm usually in DS mode around town.

by **G_whizz** » Sat Jun 06, 2009 2:38 pm

audtatious wrote:Take it in for service. It should be smooth.

Welcome to NICO!

Agreed. You bought a beautiful car! It should run flawlessley!

Welcome to your new home!

by **SteveTheTech** » Sat Jun 06, 2009 4:45 pm

Welcome mkt and TommyC3, congrats on the G37s. It's a great car from the limited experiences I have had driving them. It would be one of the best ways to drive to work in the morning.

Ok I think I have an idea of what you are experiencing here but it makes perfect sense. On Monday I will look into this a little more to see if there is a reprogram that addresses this.

If you let off the gas while cruising the TCM will alter the gear range to try to better assist you when you need to accelerate again. While the car is dropping gears and speed is decreasing (at whatever pace it may be) at some point the (I do not have access to the 09 service manual ATM) the Overrun Clutch Engages, providing what is typically referred to as "Engine Braking" as the car normally upshifts through third gear (known example) Engine Braking will be felt. I am not 100% clear on the upshift logic of the RE7 but I will look into this when I get back to work.

It is basic shift logic principals using an overrun clutch and I do not know if that will be something that can be adjusted. Infiniti tried to remove the hunting feeling common in other 7+ speed transmissions.

Of the members that have this model what do you think of the long term personal satisfaction from the 7AT. From the few times I have driven them the acceleration seems like something that needs some getting used to. I found myself exceeding the speed limit at an amazing pace while entranced by the 3.7 VQHRs amazing sound.

by **audtatious** » Sat Jun 06, 2009 6:46 pm

The only "issue" I have had with the tranny is when manually shifting. Downshift from 3-2 for a right-hand turn, turn at 20-ish, downshift to 1st and it stays in-between gears for about 3-5 seconds which is annoying.....RPM's are well within range and it should simply kick it down.

by **mkt** » Sat Jun 06, 2009 9:20 pm

Thanks for the reply all,

They have been helpful. I decided to take it into service on Monday. I'll keep everyone posted with the results

by **SteveTheTech** » Sun Jun 07, 2009 6:16 am

audtatious wrote:The only "issue" I have had with the tranny is when manually shifting. Downshift from 3-2 for a right-hand turn, turn at 20-ish, downshift to 1st and it stays in-between gears for about 3-5 seconds which is annoying.....RPM's are well within range and it should simply kick it down.

Huh check this out. It is supposed to hold the shift.

The operation is different on this model in comparison to older more traditional hydraulically controlled automatic transmissions. The additional electronic solenoids allow the TCM to more precisely control shift points, engine braking and advanced lock up duty cycle control. Allot of these types of things are not going anywhere and are going to be attributes of more modern transmission. Even compared to your Maxima the G uses a very different setup. The Max only had 4 linear solenoids (I think) and rudimentary oversight.

by **mkt** » Tue Jun 09, 2009 1:12 pm

Hi all

So I took my car to the dealer yesterday. They ran an engine diagnositc test and nothing appears to be wrong with the car. The not smooth down shift is just the way the car is designed. However, if you are annoyed with it, there's good news. The tech told me they just came out with a new update (June 03, 09) for the 09 G37 coupe. It's so new he didn't get a chance to read what it actually does. He's suspicious it might fix my problem so I went ahead and asked him to install the updates. After that, we took it for a test drive and the car is a lot more smooth on the downshift.

If you have a 09 g37 coupe and are having this similar problem, it's worth having the updates...will make the drive a lot smoother, that's from my experience

by **av8or** » Tue Jun 09, 2009 2:43 pm

you drive a g47 coupe?

by **abice** » Tue Jun 09, 2009 5:50 pm

I just bought my 09 G37 on June 1st Ive had it for a week now havent really noticed the down shifting problem ive been mostly in ds and doing the down shifting myself also when i felt something similar to what ur describing I just kind of ignored it I felt that the car has seven gears 330 horsepower it doesnt want to be in 3 and 4th gear going 40 miles an hour it wants to breathe and be at about 80 miles an hour in 6 and 7 gear so i just kind of ignored it but if theres a very new update for the 09 G37s with the automatic transmission MKT is it worth getting and is it under warranty and did u have to pay anything for it to be updated? please let me know MKT

by **Graflo** » Wed Jun 10, 2009 1:58 am

I have the Sedan... I wonder if I should get the same update... I noticed it but realized that it was keeping the revs up so if I wanted to goose it she was ready...begging for it.

by **mkt** » Wed Jun 10, 2009 8:24 am

Hi guys

This is all covered in the warranty. No need to pull money out of your wallet. Sorry, I didn't catch the name of the update, it was released in June 03, 09. If you have the warranty, which you should, it's definitely worth bringing it back for updates...

Hope this helps

by **TommyC3** » Wed Jun 10, 2009 3:29 pm

Thanks Mkt for the update. I'll have to ask the dealer if they have that update for the sedan.

Steve the tech, thanks for sharing the diagram. There's some good info there.

by **SteveTheTech** » Wed Jun 10, 2009 4:02 pm

There is a broad spectrum fix in the works. At this time that is all I know is it's in final testing stages. Shouldn't be too long now that there is a verified fix.

The day I see this pop up on my work computer I will post it here and let you guys know. Since it is a reflash and no parts are required to resolve this the turn around time shouldn't be more than an hour.

I really hope that anyone that has the "pre-release" version will post up when they adaptives are set (usually within 100-200 miles depending on driving pattern) as to the overall results of the software alteration.

by **abice** » Mon Jun 15, 2009 4:06 am

Mkt I went to my dealership and I just bought my car two weeks prior and asked about an update regarding the transmission in the car and the service manager told me that there was an update for the 2008 G37 but not for the 2009 G37 is this the update you were talking about? Please let me know and if you have the 2009 G37 you have to let me know more information about the update so I can go to my dealership with the exact information. Thanks mkt

by **SteveTheTech** » Fri Jun 26, 2009 3:04 am

Great news,

Infiniti released a reflash for the TCM to resolve this issue.

The applicable vehicles are as follows for ITB09-032

2009 FX 35 (S51) 2WD
2009 FX 35/50 (S51) AWD
2009 G37 Sport Sedan (V36) 2WD and AWD
2009 G37 Sport Coupe (CV36) 2WD and AWD
2009 M35 (Y50) 2WD ONLY

I hope this helps

by **Pamywyner** » Fri Jun 26, 2009 4:26 pm

Just picked up an '09 G37 X sedan today and noticed that while I was decelerating down a hill, it felt as if it was braking on it's own and the RPM's were rising as well. Sounds like this is the same issue that's being written about. Might take it in for the update. Hope this new 7 speed trans proves to be a good choice.

Love the car so far!!!!

by **G_whizz** » Fri Jun 26, 2009 4:31 pm

Ahhh...so ya picked her up eh??!!

CONGRATS!!

I would get this in there asap and get er dun..

by **SteveTheTech** » Fri Jun 26, 2009 5:43 pm

Pamywyner wrote:Just picked up an '09 G37 X sedan today and noticed that while I was decelerating down a hill, it felt as if it was braking on it's own and the RPM's were rising as well. Sounds like this is the same issue that's being written about. Might take it in for the update. Hope this new 7 speed trans proves to be a good choice.

Love the car so far!!!!

Well I am glad to hear you are happy with it so far. It really seems like this reflash will help with some of the adaptive logic settings. I noticed this a while back with one of the first RE7s equipped Gs that I had the fortune of driving, it accelerated well but it would engine brake at the wrong time.

Given the conventional overrun clutch operation in 4 speed w/ OD transmission we were all accustom to in the days of yore and attribute we all became to. I am thinking engine braking while the transmission was in first and third gear range. The RE7 operates slightly differently. If you are curious I can try to dig up some more technical information about it.

G_whizz wrote:eh??!!

Exclamation and or Question there Frenchy

by **G_whizz** » Fri Jun 26, 2009 5:49 pm

SteveTheTech wrote:

Exclamation and or Question there Frenchy

I don't know what you're talking abooot.

by **audtatious** » Fri Jun 26, 2009 6:00 pm

Quote »

The only "issue" I have had with the tranny is when manually shifting. Downshift from 3-2 for a right-hand turn, turn at 20-ish, downshift to 1st and it stays in-between gears for about 3-5 seconds which is annoying.....RPM's are well within range and it should simply kick it down.While I had my car in for service I brought up this issue with the dealership. Upon a test drive they noticed the same issue and opened a case with Infiniti on it for corp to figure out a fix. IF they come out with a TSB to fix my particular issue I'm supposed to get a call back to have it fixed.

audtatious

Posts: 28405

Joined: Sun Oct 27, 2002 5:31 pm

Car: 2008 G37s Coupe - 2007 G35s Sedan

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Re: FN-QR (audtatious)

by SteveTheTech » Sun Jun 28, 2009 9:07 am

audtatious wrote:IF they come out with a TSB to fix my particular issue I'm supposed to get a call back to have it fixed.

So the know you know about this information before they do is that what you are eluding to or was that sarcasm.

Since your car and the 09 have different transmissions and only the RE7R07a is addressed in this bulletin. I had spent some time researching your complaint and I have some very interesting information regarding the 07-08 RE5R05a. However I was told in no uncertain terms they will be doing nothing about this until they can get an idea of how many effected units there are.

So it looks like it is going to take some time to address this as the shift logic software modification requires testing for federal standards before it can be released. The RE7 update actually went from final testing to available quickly so this is promising that in the future they be able to almost streamline the process.

Or they could give a few technicians access to approved levels of software modification. It should not be hard to do since they frequently modify the software but at this point have no ability to use our interface to adjust base settings in the driveline. The vehicles electrical systems are very adaptable but that only applies to the BCM and AV.

Oh well there is always something to complain about they fixed the RE7 issue, the steering rack issue on M and EX, and the FP and steering column on the EX in the past few months so they are working on fixes for customer satisfaction issues.

SteveTheTech

Posts: 3687

Joined: Sat Aug 16, 2008 3:20 pm

Location: Alexandria Va

Car: 95 J30

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Re: FN-QR (SteveTheTech)

by audtatious » Sun Jun 28, 2009 12:47 pm

No sarcasm, just regurgitating what I was told via the service adviser.

audtatious

Posts: 28405

Joined: Sun Oct 27, 2002 5:31 pm

Car: 2008 G37s Coupe - 2007 G35s Sedan

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G37 Downshift not smooth TSB Released!