Transmission down shifting issue - Fuzzy logic
#1
Transmission down shifting issue - Fuzzy logic
I have 2010 G37 Sedan (Journey+Prem+Navi). When I am driving in sports mode (DS) and slow down due to traffic or exiting the freeway, the RPM jumps out and revs from 2k to 4k . Its down shifting very aggressively .
Also if I switch to manual from DS by pushing the tranny stick down , the RPM goes to 5k!
Test drove another 2010 G37 off the lot , it did not have the problem. Complained to service manger and he reset the transmission fuzzy logic and the problem went away!!!
However two weeks later, the problem has come back. Now I do tend to drive a bit aggressively but I certainly don't red-line the engine or anything like that. This whole tranny logic is a mess. I'm a bit disappointed in Infiniti. The whole reason I bought this over the Acura TL was to enjoy the performance characteristics. Now, its more of a 'watch and debug issues' routine.
Also if I switch to manual from DS by pushing the tranny stick down , the RPM goes to 5k!
Test drove another 2010 G37 off the lot , it did not have the problem. Complained to service manger and he reset the transmission fuzzy logic and the problem went away!!!
However two weeks later, the problem has come back. Now I do tend to drive a bit aggressively but I certainly don't red-line the engine or anything like that. This whole tranny logic is a mess. I'm a bit disappointed in Infiniti. The whole reason I bought this over the Acura TL was to enjoy the performance characteristics. Now, its more of a 'watch and debug issues' routine.
#2
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Your tranny is working how it should. In DS it will downshift more aggressively(like a sport car should). If you bought this car for performance, then this is a feature you should enjoy
If you don't like aggressive downshifting, then why aren't you just leaving it in D? Oh, and when you are in DS and shift DOWN a gear, then of course it's going to rev up the RPMS!!
There is definitely some "fuzzy logic" going on here
If you don't like aggressive downshifting, then why aren't you just leaving it in D? Oh, and when you are in DS and shift DOWN a gear, then of course it's going to rev up the RPMS!!
There is definitely some "fuzzy logic" going on here
Last edited by mindonmatter; 09-09-2010 at 12:50 PM.
#3
The RPM rev is completely disproportional to the speed. If I am in DS, driving at 65, then I slow down to take an exit ramp, and shift to manual, It goes to 3rd gear @ 5000 rpm! This is not sports car'ish. This is buggy software. There is a BIG difference between aggressive shifting , poor tranny ratios and buggy fuzzy logic
#4
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Okay man, if you are in DS at 65mph, then most likely your RPM's are already somewhat high and you're in 4th. Then, if you use the shift lever and move it down, then of course it's going to downshift into the next lowest gear(3rd) and your RPM's are going to jump. What else would you expect? It's not going to downshift and stay at the same RPM. If you don't want it to downshift(raise RPMS), then don't move the lever down?!? If you'd rather lower the RPM's, move the lever UP to upshift. There is definitely a logic problem here
Just to be clear......
You can switch to manual by UPshifting as well as DOWNshifting.
Just to be clear......
You can switch to manual by UPshifting as well as DOWNshifting.
#5
Pushing the paddle shifter or stick up or down will result in an immediate up or downshift. I think the confusion here is that you're expecting that action to place the transmission in manual mode only without changes. As you noticed, that's not the case.
If you want the car to shift less aggressively, don't use the DS mode, which is intended to be aggressive!
And please don't complain to the dealer if you find DS to be too aggressive. Lame complaints like these result in watering down great cars so they can be more vanilla.
If you want the car to shift less aggressively, don't use the DS mode, which is intended to be aggressive!
And please don't complain to the dealer if you find DS to be too aggressive. Lame complaints like these result in watering down great cars so they can be more vanilla.
#6
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iTrader: (2)
Pushing the paddle shifter or stick up or down will result in an immediate up or downshift. I think the confusion here is that you're expecting that action to place the transmission in manual mode only without changes. As you noticed, that's not the case.
If you want the car to shift less aggressively, don't use the DS mode, which is intended to be aggressive!
And please don't complain to the dealer if you find DS to be too aggressive. Lame complaints like these result in watering down great cars so they can be more vanilla.
If you want the car to shift less aggressively, don't use the DS mode, which is intended to be aggressive!
And please don't complain to the dealer if you find DS to be too aggressive. Lame complaints like these result in watering down great cars so they can be more vanilla.
#7
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One thing i've noticed in DS mode (not manual) is that sometimes when I am going very slowly like in a jam, the car stutters around a bit. It acts jerky. It definitely doesn't feel like a "feature" :P
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#8
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also keep in mind while in manual mode, the trans will still downshift automatically. lets say when your slowing down in manual mode you want to go from 4 to 3 then before you realize it the trans automatically does 4 to 3 then you downshift and and your in 2.
#11
I heard the g tranny is an adaptive one and adapts to driving habits, thats why wen the service guy reset it, it went to normal for a couple weeks untill it got used to the way ur foot hits the gas...
#12
Registered User
you're not supposed to use DS while in traffic. i know what you mean about the jerkyness....the car is trying to hold ur gear and keep the revs high...meanwhile ur trying to slow down........its an inverse and the car bogs down (similar to engine braking)
#13
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I have a habit of using DS mode in traffic jam. This is a great way to change lanes back and forth to increase my flow rate in the jam. I tried to stay in D, but sometimes the response time is a little slow...the other guy is already (or almost) parallel to me and can't squeeze in to that lane. With DS mode on, the other driver usually don't have a chance to block me from changing lane.
In general, people here in NYC don't yield, so I have to EARN the spot in front of them, DS helped me a lot in this respect.
In general, people here in NYC don't yield, so I have to EARN the spot in front of them, DS helped me a lot in this respect.
#14
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^^^ +1
DS and manual mode (for the most part) don't mix well with traffic. Exactly for the reason carz said. If you let off the gas at low speed and higher rpm in 1st or 2nd, the car will do quite a bit of engine braking, and then give it a little gas and then the car tries to get going again. So you end up getting an accel/decel jumpiness or jerking.
DS and manual mode (for the most part) don't mix well with traffic. Exactly for the reason carz said. If you let off the gas at low speed and higher rpm in 1st or 2nd, the car will do quite a bit of engine braking, and then give it a little gas and then the car tries to get going again. So you end up getting an accel/decel jumpiness or jerking.