7AT Problem?

jpritche · 05-27-2012, 11:27 AM

Quote:

Originally Posted by UNKNOWN_370

That's called DOWNSHIFT REV MATCH brother. What's being called a bump is your DRM is always active on manual mode. Its there so when you are on a highway, you can get an extremely fast throttle response when downshifting on the accelerator. When you downshift, say to a stop sign, you will feel the same thing. Under decel that would be called engine braking. There's nothing wrong with the car. If you don't want to feel it. Keep the car in D and only shift when you need to. Then let auto mode downshift for you.

Quote:

Originally Posted by danelonson

That's the issue...it jerks when the car is in D shifting from 2nd to 1st. I never manually shift.

Right it does it in D also, I was just telling him to put it in manual mode that way he could physically see when it was happening.

I agree though, if you manually downshift, you will jerk a lot from the revs jumping up and the engine starting to brake hah.

danelonson · 05-27-2012, 12:18 PM

Yes putting it in manual mode verified that it's normal.

UNKNOWN_370 · 05-27-2012, 12:32 PM

Quote:

Originally Posted by danelonson

That's the issue...it jerks when the car is in D shifting from 2nd to 1st. I never manually shift.

The only thing I can think of is if you are trying to make Andretti stops on the street? The ECU will use DRM to assist in engine braking as well as braking in order to give you more controlled and quicker stops. Sometimes my AT makes lil noises but I ignore most of them unless they cause some type of abnormal NVH. Nissans are loaded with tech that are always helping you do something. Occasionally you will hear them.

Also, I'm going to strongly go with you are also feeling ABS. That's it. Nothing more!!

danelonson · 05-27-2012, 01:01 PM

Quote:

Originally Posted by UNKNOWN_370

Also, I'm going to strongly go with you are also feeling ABS. That's it. Nothing more!!

I'm not feeling ABS. 100% sure of that. I'm not braking hard enough for ABS to kick in.

MDZOwner · 05-27-2012, 10:05 AM

I have the same situation. Sometimes the ecu is faster to the down shift in manual mode then I am so it feels like we had a split second disagreement but the ecu wins every time. For me I found slowing earlier and smoothing out the distance to stop in lower gears helps.

I have to say I kinda love the feeling it reminds me I am not in a sedan

danelonson · 05-27-2012, 10:25 AM

Thanks jpritche you're absolutely right. I went out this morning and put it in manual mode while braking and the "jerk" that I feel is the shift from 2-1. I feel sooooo much better...thought something was wrong with my car. Thanks everybody for the input and help!

UNKNOWN_370 · 05-27-2012, 10:41 AM

Quote:

Originally Posted by MDZOwner

I have the same situation. Sometimes the ecu is faster to the down shift in manual mode then I am so it feels like we had a split second disagreement but the ecu wins every time. For me I found slowing earlier and smoothing out the distance to stop in lower gears helps.

I have to say I kinda love the feeling it reminds me I am not in a sedan

tower74 · 05-27-2012, 12:31 PM

I have had the same issue. It only happens in manual side and also only when the car is hot. I just down shift from 3rd to 2nd and problem solved. Plus I'm putting a lot more torque on the tranny than stock so I try to play it safe and do it for the car instead of waiting for it to down shift.

Pauly · 05-29-2012, 08:32 AM

ive noticed it in the same range. rarely happens. usually on moderate braking (not hard braking). its just the car doing its thing, but if it concerns you, have them look into it for documentation's sake

NBZ34 · 05-29-2012, 04:13 PM

I have a 2012 and havent experienced any 'hard' downshifting in either auto or manual modes.... Unless i intend for it to torque hard.

Sent from my HTC Evo using Tapatalk 2

danelonson · 05-29-2012, 04:55 PM

I just found this thread on here that shows others having the same issue.

Automatic 2-1 rough downshifting

wilsonp · 05-29-2012, 10:54 PM

And others don't

If I downshift manually, shifting two gears down from 4 to 2, it sometimes seems to be missing the DRM and I get a large lurch, but coasting down is always smooth from 3 to 1 - the only lurch I feel is from 4 to 3. I tried to pay attention today in D or M didn't matter.

d15b7 · 06-20-2012, 10:14 PM

Quote:

Originally Posted by danelonson

I purchased my '12 Z almost two months ago and ever since the first day I purchased the car, whenever I brake hard I feel a "thump" in the transmission as my speed decreases. I did a search and found that some 7AT have hard 3rd-2nd shifting and/or 2nd to 1st. Is this what I'm experiencing? If I brake softly then it doesn't do it. Its as if the transmission mounts are loose or something. Please help

Got this exact issue with my almost two months new 7AT too (car built in Feb 2012). very ignoring. I'm conditioned to get nervous everytime I came to a stop light now.

danelonson · 06-21-2012, 04:29 PM

Quote:

Originally Posted by d15b7

Got this exact issue with my almost two months new 7AT too (car built in Feb 2012). very ignoring. I'm conditioned to get nervous everytime I came to a stop light now.

I feel as if my car is doing this less now than it did when I first purchased it.

It still does it just not at every stop anymore. I now have 1,300 miles so hopefully it completely goes away. I know how you feel about getting to a stop light...its very frustrating for this to happen to a new car. And the worst part about this is that it is a common problem for the AT.

ewgillis · 07-01-2012, 09:34 AM

I've experienced this for two years now. 3-2 and 2-1, and this is when letting the car downshift automatically, not doing a manual downshift. It happens when braking harder at the light, but I've also braked really soft to see if it would go away, and it still clunks pretty hard. I've felt varying degrees of the clunk from moderate to actually getting lurched forward and hearing a slight grind. It comes and goes, which to me is an indication that it's electronically induced from recent driving style, etc. I've noticed over time that after doing some harder driving and higher rev upshifts that it starts doing this. The only thing that seems to make it go away is taking it out of MM, which instantly makes it go away, and driving more conservative for a few days. Then going back to MM, it's completely gone for weeks at time. I would say each summer I've driven the car maybe 5000 mi and have experienced this about 8 times for a period of 2-3 days each occurrence over that time. I brought it up with the dealer, but was not experiencing it at that moment. They said to bring it over some time when it is occurring, but with my schedule, easier said than done. This year I had the worst clunk so far. I thought there would be parts left in the street. Would love to see how much metal is in the transmission fluid.

05-29-2012, 08:32 AM	#9 (permalink)
Pauly Track Member Join Date: Feb 2012 Location: Lafayette, La Posts: 645 Drives: and parks Rep Power: 15	ive noticed it in the same range. rarely happens. usually on moderate braking (not hard braking). its just the car doing its thing, but if it concerns you, have them look into it for documentation's sake __________________ Gun Metallic 2012 370 Z 7AT

05-29-2012, 04:13 PM	#10 (permalink)
NBZ34 Enthusiast Member Join Date: Jan 2012 Location: New Braunfels, TX Age: 54 Posts: 467 Drives: '12 Touring AT Sport Rep Power: 14	I have a 2012 and havent experienced any 'hard' downshifting in either auto or manual modes.... Unless i intend for it to torque hard. Sent from my HTC Evo using Tapatalk 2 __________________ *CHRIS* 開田 2012 370Z MB Touring/Sport/AT/Nav \| Takeda \| Fast Intentions \| SWIFT \| H&R \| UpRev \| Michelin PSS \|

05-29-2012, 10:54 PM	#12 (permalink)
wilsonp A True Z Fanatic Join Date: Jul 2010 Location: Virginia Posts: 1,134 Drives: 2009 Touring Sp Nav Rep Power: 17	And others don't If I downshift manually, shifting two gears down from 4 to 2, it sometimes seems to be missing the DRM and I get a large lurch, but coasting down is always smooth from 3 to 1 - the only lurch I feel is from 4 to 3. I tried to pay attention today in D or M didn't matter. __________________ 2014 Cayman S PDK Sport Chrono White/Black Was 2009 370Z Touring Sport+Nav 7AT Metallic Black/Persimmon Was 1991 NSX Auto Black/Black

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05-27-2012, 12:18 PM	#2 (permalink)
danelonson Base Member Join Date: Apr 2012 Location: Florida Posts: 82 Drives: 12 370z 7AT Sport Rep Power: 13	Yes putting it in manual mode verified that it's normal.

05-27-2012, 10:05 AM	#5 (permalink)
MDZOwner Base Member Join Date: Dec 2010 Location: Maryland Posts: 77 Drives: 09 370z Rep Power: 16	I have the same situation. Sometimes the ecu is faster to the down shift in manual mode then I am so it feels like we had a split second disagreement but the ecu wins every time. For me I found slowing earlier and smoothing out the distance to stop in lower gears helps. I have to say I kinda love the feeling it reminds me I am not in a sedan

05-27-2012, 10:25 AM	#6 (permalink)
danelonson Base Member Join Date: Apr 2012 Location: Florida Posts: 82 Drives: 12 370z 7AT Sport Rep Power: 13	Thanks jpritche you're absolutely right. I went out this morning and put it in manual mode while braking and the "jerk" that I feel is the shift from 2-1. I feel sooooo much better...thought something was wrong with my car. Thanks everybody for the input and help!

05-27-2012, 12:31 PM	#8 (permalink)
tower74 A True Z Fanatic Join Date: Oct 2011 Location: KCMO Posts: 1,597 Drives: 2017 ZL1 Camaro Rep Power: 370	I have had the same issue. It only happens in manual side and also only when the car is hot. I just down shift from 3rd to 2nd and problem solved. Plus I'm putting a lot more torque on the tranny than stock so I try to play it safe and do it for the car instead of waiting for it to down shift.

05-29-2012, 04:55 PM	#11 (permalink)
danelonson Base Member Join Date: Apr 2012 Location: Florida Posts: 82 Drives: 12 370z 7AT Sport Rep Power: 13	I just found this thread on here that shows others having the same issue. Automatic 2-1 rough downshifting

07-01-2012, 09:34 AM	#15 (permalink)
ewgillis Base Member Join Date: Nov 2010 Location: USA Posts: 10 Drives: 2009 370Z Rep Power: 15	I've experienced this for two years now. 3-2 and 2-1, and this is when letting the car downshift automatically, not doing a manual downshift. It happens when braking harder at the light, but I've also braked really soft to see if it would go away, and it still clunks pretty hard. I've felt varying degrees of the clunk from moderate to actually getting lurched forward and hearing a slight grind. It comes and goes, which to me is an indication that it's electronically induced from recent driving style, etc. I've noticed over time that after doing some harder driving and higher rev upshifts that it starts doing this. The only thing that seems to make it go away is taking it out of MM, which instantly makes it go away, and driving more conservative for a few days. Then going back to MM, it's completely gone for weeks at time. I would say each summer I've driven the car maybe 5000 mi and have experienced this about 8 times for a period of 2-3 days each occurrence over that time. I brought it up with the dealer, but was not experiencing it at that moment. They said to bring it over some time when it is occurring, but with my schedule, easier said than done. This year I had the worst clunk so far. I thought there would be parts left in the street. Would love to see how much metal is in the transmission fluid.