G37 Transmission Issues with 4th -> 3rd Downshift

[Mockenrue]

I learned a lot about these issues at my dealership yesterday. It turned out that I already had the latest TCM version (ie. the downshift fix) but not the latest ECM version (ie. flare issue). Strangely enough, I did have downshift symptoms. Here is what I could reproduce almost every time:

1. In two places on my drive home, the car down-shifted suddenly/harshly when going around an up-hill curve.

2. At one stop sign on a down slope, when I accelerated out of it, the car hesitated for a moment and "clunked" before acceleration.

3. When coasting with foot off pedal at about 35-40mph, the car downshifts and applies engine breaking requiring more acceleration.

Behavior similar to #1 and #2 also happened at random times in my general driving. I did not notice the rpm flare at any time.

Well, I wasn't too happy when he said he could not do a downshift reflash for me. However, he said that some drivers have seen an interrelation with the ECM flare fix. He did that for me and explained exactly what it did (something to do with the ratio of the throttle and intake). He also showed me all of his equipment, gave me screen prints of the ECU part numbers for both flashes, and had me watch as he did the reflash. He also told me that the ECM flare fix is a prerequisite to the TCM tranny fix, so if you got the second, you got the first. Finally, he told me about the "number" we all have that corresponds to our driving syle. 100 is the starting point and you go up if you drive easy and down if you drive hard. My number was 99, though I expect it will get lower since much of my time was easy due to break-in. As others have said, the number can change transmission characteristics.

Anyway, here are the results of JUST the flare fix:

1. I tried both hill locations three times, and the rough downshift did not happen even once. This one was reproducable 100% of the time.

2. The clunk downshift on acceleration (that was reproducable at least 50% of the time at a certain stop sign) has not occurred in three tries.

3. This did not change. The 4->3 shif is sitll earlier than some other cars that I've owned, but it never has been "rough" for me. Engine breaking is still present. I think this what others have been saying is normal.

4. Another benefit: the car doesn't drive as "heavy" now (see my inital reactions post). Initial throttle response is quicker and you don't have to toe in as much to jump off the line. The tech suggested this might be the case since there is no hesitation around intake. Again, not sure of the details.

Bottom line: some of what you may attribute to the downshift fix may be the sneaky flare fix.

[njchen24]

I just took the car to the dealer today and ask the tech apply the TSB. He show me on the Infinity diagnostic computer screen that this TSB09-032 doesn't exist. Am I missing something?

[SkyMG37x]

Originally Posted by njchen24

I just took the car to the dealer today and ask the tech apply the TSB. He show me on the Infinity diagnostic computer screen that this TSB09-032 doesn't exist. Am I missing something?

Ask them to call their technical support line, or take it to another dealer. You should print the front page of the bulletin - it's in the link in the original post. It's ITB09-032.

[brynomon]

Originally Posted by njchen24

I just took the car to the dealer today and ask the tech apply the TSB. He show me on the Infinity diagnostic computer screen that this TSB09-032 doesn't exist. Am I missing something?

Of course it won't exist on their system if they haven't performed this before. They need to get the updates. You can have them browse to the infiniti TSB archives at http://www.infiniti-techinfo.com/TSB...=+G37+(V36)+09. The other poster is right. They should work up their chain if they do not understand any of this or get it, but that would scare me into taking my car elsewhere.

I'm really getting to see the differences in service levels through this whole thread. It's great when a service department listens and cooperates but aggravating to no end when they won't listen because they don't want to believe that a customer would know more than them. My old Nissan dealer never wanted to listen and it turned out there were tons of TSB's on the issues related to my problems. I had a Nissan 04 Maxima SE and that was their worst year ever.

[sbebs2000]

Originally Posted by Mockenrue

I learned a lot about these issues at my dealership yesterday. It turned out that I already had the latest TCM version (ie. the downshift fix) but not the latest ECM version (ie. flare issue). Strangely enough, I did have downshift symptoms. Here is what I could reproduce almost every time:

1. In two places on my drive home, the car down-shifted suddenly/harshly when going around an up-hill curve.

2. At one stop sign on a down slope, when I accelerated out of it, the car hesitated for a moment and "clunked" before acceleration.

3. When coasting with foot off pedal at about 35-40mph, the car downshifts and applies engine breaking requiring more acceleration.

Behavior similar to #1 and #2 also happened at random times in my general driving. I did not notice the rpm flare at any time.

Well, I wasn't too happy when he said he could not do a downshift reflash for me. However, he said that some drivers have seen an interrelation with the ECM flare fix. He did that for me and explained exactly what it did (something to do with the ratio of the throttle and intake). He also showed me all of his equipment, gave me screen prints of the ECU part numbers for both flashes, and had me watch as he did the reflash. He also told me that the ECM flare fix is a prerequisite to the TCM tranny fix, so if you got the second, you got the first. Finally, he told me about the "number" we all have that corresponds to our driving syle. 100 is the starting point and you go up if you drive easy and down if you drive hard. My number was 99, though I expect it will get lower since much of my time was easy due to break-in. As others have said, the number can change transmission characteristics.

Anyway, here are the results of JUST the flare fix:

1. I tried both hill locations three times, and the rough downshift did not happen even once. This one was reproducable 100% of the time.

2. The clunk downshift on acceleration (that was reproducable at least 50% of the time at a certain stop sign) has not occurred in three tries.

3. This did not change. The 4->3 shif is sitll earlier than some other cars that I've owned, but it never has been "rough" for me. Engine breaking is still present. I think this what others have been saying is normal.

4. Another benefit: the car doesn't drive as "heavy" now (see my inital reactions post). Initial throttle response is quicker and you don't have to toe in as much to jump off the line. The tech suggested this might be the case since there is no hesitation around intake. Again, not sure of the details.

Bottom line: some of what you may attribute to the downshift fix may be the sneaky flare fix.

Great info! Did your print outs give you any detail or firmware version number for the ECM version that it was or the new one for the flare fix?

[Mockenrue]

Originally Posted by sbebs2000

Great info! Did your print outs give you any detail or firmware version number for the ECM version that it was or the new one for the flare fix?

One screen print shows:ECU Part number: 23710-JU60B

The other is: ECU Part number: 31039-3R0D

I'm not 100% sure, but I think the first one is the TCM, and the second is the ECM. I'm also not sure if those are just part numbers, or if they include the firmware versions.

[sbebs2000]

Originally Posted by Mockenrue

One screen print shows:ECU Part number: 23710-JU60B

The other is: ECU Part number: 31039-3R0D

I'm not 100% sure, but I think the first one is the TCM, and the second is the ECM. I'm also not sure if those are just part numbers, or if they include the firmware versions.

Thanks again, I see two others have gotten the below for the TCM

Performed Bulletin 09-032 Reprogrammed TCM

Replace old part #31039-1XJ4A new part #31039-3RX0C

[Radius]

Very interesting posts. Thanks to all.

I might be a bit of an anomalous driver in that I drive 99% of the time via paddles in DS. So, my concern would be whether these reflashes affect the speed/crispness etc of manual shifting. Personally, I would prefer quicker shift speeds in manual mode but imagine that will never happen. Think VW/Audi DSG if you have ever driven one. Almost bought an R32, A3 3.2 S Line for this reason.

I have not had the reflashes since I don't want the car to behave less aggressively when in manual mode. Of course the reflashes could potentially improve DS manual mode just haven't been able to discern that result from any threads.

Any insights from manual DS mode users?

[brynomon]

Originally Posted by Radius

Very interesting posts. Thanks to all.

I might be a bit of an anomalous driver in that I drive 99% of the time via paddles in DS. So, my concern would be whether these reflashes affect the speed/crispness etc of manual shifting. Personally, I would prefer quicker shift speeds in manual mode but imagine that will never happen. Think VW/Audi DSG if you have ever driven one. Almost bought an R32, A3 3.2 S Line for this reason.

I have not had the reflashes since I don't want the car to behave less aggressively when in manual mode. Of course the reflashes could potentially improve DS manual mode just haven't been able to discern that result from any threads.

Any insights from manual DS mode users?

The changes effect all modes of the tranny. Including DS or DS(M). This is because there was a problem with the way the computer was having different components interact. We have one fancy tranny and they messed up with it big at first but now... WOW. It will smooth out all downshifts in any mode. I drove a bit today in non rush hour traffic with the usual congestion spots around construction. I actually didn't need to downshift at all in M mode. Before I forced the downshifts earlier (with more engine braking) so that I didn't have to anticipate the rough downshift. The car is nimble quick and comfortable to drive no matter what my style is. I can coast more or I can push her hard. It doesn't matter. Its a much smoother ride and easier too. I had thoroughly enjoyed M mode today.

[Radius]

Originally Posted by brynomon

The changes effect all modes of the tranny. Including DS or DS(M). This is because there was a problem with the way the computer was having different components interact. We have one fancy tranny and they messed up with it big at first but now... WOW. It will smooth out all downshifts in any mode. I drove a bit today in non rush hour traffic with the usual congestion spots around construction. I actually didn't need to downshift at all in M mode. Before I forced the downshifts earlier (with more engine braking) so that I didn't have to anticipate the rough downshift. The car is nimble quick and comfortable to drive no matter what my style is. I can coast more or I can push her hard. It doesn't matter. Its a much smoother ride and easier too. I had thoroughly enjoyed M mode today.

Thanks for the insight Brynomon. Appreciated. Did you happen to notice if the shifts were any slower/faster, particulalrly at WOT? As you can tell, I prefer fast, head-snapping shifts ;-) While I would welcome smoother downshifts, I am concerned that upshift speeds might be compromised.

Thanks in advance.

[brynomon]

Originally Posted by Radius

Thanks for the insight Brynomon. Appreciated. Did you happen to notice if the shifts were any slower/faster, particulalrly at WOT? As you can tell, I prefer fast, head-snapping shifts ;-) While I would welcome smoother downshifts, I am concerned that upshift speeds might be compromised.

Thanks in advance.

From what I can say the upshifting and downshifting speed is not compromised but I'm not always paying attention to it any more. Wonder what others have to say since having the update.

[saltfish]

I had the update performed on Monday at Infiniti of Manhattan and in my opinion its worth the update. The shifts seem more crisp/refined than before and i've also noticed an increase in my mpg as well. I no longer experience that weird downshift/engine braking then coast effect when traveling at slower speed as the car now coasts a lot more and behaves as expected.

Prior to the update i use to average about 13 mpg (driving in NYC traffic and being lead footed) and now i'm averaging about 16 mpg (still being lead footed) with about 9750 miles on the odometer. I haven't fully finished a tank of gas as yet so i will revise the mpg # if it differs.

In regards to manual shifts i wouldn't say that it made the shifts more quicker, however as per my experience it just seems a bit more refined. Radius i will try to do some aggressive driving in manual mode later tonight and post a better review of it.

I also have Black Betty Grounding Kit which is suppose to help with shifting in AT transmissions.

[Radius]

Originally Posted by saltfish

I had the update performed on Monday at Infiniti of Manhattan and in my opinion its worth the update. The shifts seem more crisp/refined than before and i've also noticed an increase in my mpg as well. I no longer experience that weird downshift/engine braking then coast effect when traveling at slower speed as the car now coasts a lot more and behaves as expected.

Prior to the update i use to average about 13 mpg (driving in NYC traffic and being lead footed) and now i'm averaging about 16 mpg (still being lead footed) with about 9750 miles on the odometer. I haven't fully finished a tank of gas as yet so i will revise the mpg # if it differs.

In regards to manual shifts i wouldn't say that it made the shifts more quicker, however as per my experience it just seems a bit more refined. Radius i will try to do some aggressive driving in manual mode later tonight and post a better review of it.

I also have Black Betty Grounding Kit which is suppose to help with shifting in AT transmissions.

Thanks for the update and look forward to hearing your thoughts on aggressive M mode driving (know it's a hardship so thanks).

[saltfish]

Radius as i said in my earlier post IMO the update didn't make the shifts quicker or slower, it just seems more refined/crisp, hard to explain but that just how it felt to me.

If you haven't done so as yet, you could probably try Black Betty Grounding Kit V2 which is suppose to make the shifts a bit quicker. I can't give a fair analysis on that because i had the grounding kit before i took delivery of the car and i installed them just after 2 days of having the car, however others have claimed that it helps with the shifting.

[Radius]

Originally Posted by saltfish

Radius as i said in my earlier post IMO the update didn't make the shifts quicker or slower, it just seems more refined/crisp, hard to explain but that just how it felt to me.

If you haven't done so as yet, you could probably try Black Betty Grounding Kit V2 which is suppose to make the shifts a bit quicker. I can't give a fair analysis on that because i had the grounding kit before i took delivery of the car and i installed them just after 2 days of having the car, however others have claimed that it helps with the shifting.

Thanks again for your comments.

On a humorous note, I reread your remarks about Black Betty on your first post directed at me. Thought, WTF is a Black Betty grounding kit? Certainly doesn't sound like it belongs on this forum. With my interest piqued, I spent some time today researching and have since placed an order for a set. Will report back with my impressions once installed. So, thanks for the tip.