Marc Collins

I have heard a bunch of chatter on here about this and people not knowing what was happening...or even blaming it for making them run into something in front of them.

Well, I am thoroughly impressed with my new G. For the first time since I have had the car, I had to make a sudden braking manoeuvre the other day. Driving at highway speed on an expressway and someone not paying attention cut into the passing lane in front of me (they clearly did not see me coming at a much faster speed). When I hit the brakes (not an emergency stop by any stretch, but significantly harder and faster [switch from gas to brake] than normal), the tranny simultaneously downshifted quite aggressively, assisting in slowing the car. It was precisely the proper and safest thing to do, but even with the paddles I would not have been able to execute it so quickly or proficiently.

Of course the RPM's shot up during this situation. If I didn't understand how a car works, I might have got scared and thought I was driving a Toyota with a run-away accelerator...

SkylineEX-S

I agree. If you were not aware that that was a trait of the 7AT or if you were just a average driver that did not know about downshifting I would be scared too.

That is one of the reasons that I like the DS mode durring spirited driving. It simulates the action of heal & toe downshifting while braking that is done on MT cars.

ReddieG37

iTrader: (15)

https://www.myg37.com/forums/tsb-tec...g-braking.html

Are you getting a short surge while downshifting?

Mike

iTrader: (1)

To add, even if you don't slam on the brakes, the car is capable will recognize a "panic brake" and automatically brake more for you, in addition to the engine braking.

EKinNYC

happened to me this weekend - travelling around 80mph and had to brake harder than normal to slow down for the traffic building ahead.... as i came down, definitely felt the car nudge a bit, and the needle to shoot up for a second. got a bit worried, then i realized that its prob the tranny going thru the 7 gears. didnt really have that on my (4 speed?) altima, lol

so, what exactly is the fine line between the intelligent 7AT in the car, and the need to head to the dealer for the TSB?

Hayabusa02

When I drove the car for the first time and hit the brake, I thought my feet were too big and I was heel toeing accidentally when stopping. Then...I read up and saw the car does it for you. LOL. I'm such a moron

Marc Collins

There is a normal downshifting...that most cars do and is affected by the TSB/software update. The new version is a bit less aggressive. There may be a more aggressive version in DS Mode (don't know because I never use it). I am referring to an AGGRESSIVE downshifting to accompany a panic or almost panic stop. It is nothing like the normal downshifting.

Marc Collins

Mike: what are you referring to? I have never heard of any car doing this anywhere, ever. The only feature that is available is a pre-brake mode-- when you suddenly lift off the throttle the brake shoes/pads will move closer to the disc ready to be applied anticipating a panic stop.

Are you thinking of the braking that the advanced cruise control will apply to maintain distance between you and the car in front of you?

EKinNYC

ive been reading about ppl running into other cars while braking because their engine revved... now im all paranoid. how do i tell the difference between the momentary jump in RPM during downshifting by the 7AT, and the car lurching forward because of the ECM issue?

Marc Collins

When the engine RPM's rise when you are on the brkaes, the engine is helping to slow the car, not push it forward faster. No personal disrespect intended, but you are one of the people I referred to in the initial message who would benefit from understanding how an engine and transmission work before getting a driver's license. In the olden days, this happened every time because you were using a manual transmission. Now we have masses of people who have no understanding of this...including people driving high performance 330 hp vehicles... What is wrong with this picture?

EKinNYC

no offense taken..... im coming from a smaller, less powerful car where, while this was happening, it wasnt visible. hence, here i am, trying to learn what this 330hp beast does. im all ears...

but my concern is how do you differentiate between this normal behavior, and instances like people have reported where the car revs and they cannot stop it.....

ged1067

What is wrong with this picture:

Lately, I've been using the paddle to drop the gears and help slow down the G when coming to a red light or stop sign. My previous car slowed down noticeably when I took my foot off the gas and I loved the response; the G doesn't do that, so I help.

GED

Marc Collins

One is part of a normal functioning of the car--so if you are braking hard and the car is downshifting to help the slowing process, then be happy. Variations on this happen every time you drive the car.

If your foot is on neither pedal and the engine is revving consistently upward, then you have a ECU issue. Don't hold your breath that you will ever experience this. In the one in 100,000,000 chance you do, shift into neutral right away if you are not already in neutral, bring the car to a safe stop and then shut off the engine. 99.99% of the time a restart would reset/cure the problem. If it did not, don't drive the car and call roadside assistance. Your odds of this happening are approximately the same as getting hit by lightning twice, so don't let it affect your enjoyment or peace of mind when you drive your car. Advanced driving lessons so you can safely handle your "beast" would be a million times more useful.

Marc Collins

The earlier versions had a more aggressive slowing and lots of people complained about it so they reprogrammed the tranny to act a bit more like a traditional autobox. Your previous car was atypical for an automatic if it was more aggressive than a G--what was it?

Mike

iTrader: (1)

I'm referring to brake assist. Most modern cars have it. If you press the brake pedal faster than a pre-set speed, the car will automatically go to nearly full ABS until you let go of the pedal.



http://en.wikipedia.org/wiki/Emergency_Brake_Assist


This is not the Preview Braking system that comes with ICC; that just pre-pressurizes the brake system if ICC sees you approaching a brick wall or distance between you and the car in front of you starts to suddenly decrease.