Craig K. Balgobin

My 95 gxe automatic downshifts are really delayed. I will we cruisin and when I floor the pedal I have to wait a day and a half for the car do downshift and hit a sprint. Is there any minor things I can do to improve this.

Sonic

Drive agressively more often. When I drive agressively for a while, the tranny computer must figure that I want faster downshifts and doesn't hesitate as much. You can also turn off overdrive before you anticipate accelerating, it locks out 4th gear. Watch how fast someone posts, get a 5 speed.

gtr_rider

iTrader: (50)

what he said, the more often you punch it the less the delay gets because the computer learns your driving habits.

brubenstein

More likely that the fluid is thining out from the added heat of "punching it", so the valves can work faster. It's a good indication that you probably have varnish and gum in the transmission, and the fluid needs to be changed.

Daniel B. Martin

We hear "the computer learns" fairly often. It is true that the Engine Control Module continuously recomputes the Short Term Fuel Trim and Long Term Fuel Trim. These two engine management parameters might be thought of computer "learning" but it is more correct to say the computer "learns" about the engine's behavior than the driver's habits.

I have never heard or read anything about the Transmission Control Module "learning" anything. I'm not saying you are wrong, I am asking for more information. Please provide a pointer to any service manual, book, magazine, or newspaper article which provides information about a Nissan TCM "learning". I always want to learn more and will follow up on your pointers. Thank you.

punabuds

yeah, I've seen the same problem with my 97 GLE when I first picked it up. I ran some of that Fuel system cleaner through the engine and replaced the stock air filter with a K&N drop in and that has greatly decreased the pedal stomp to engine downshift time.

Christian

dmbmaxima2k2

iTrader: (1)

yes i noticed that frequent flooring of the pedal help. Also try this, there is a pedal block that is black and somewhat hidden under the floor mat. Unscrew that, took 30 seconds and use the top of the pedal. I can get my auto to downshift in a split second now, wait until DON gets ahold of my VB, hehe.

WaarrEagle

iTrader: (1)

I saw that there the other day and wondered what it was for. Isn't it there for a reason?? What does taking it out do? Allow the pedal to go down further?

teejnut

iTrader: (8)

what does this do..? do u just take it out?

Matrix

I've noticed with my auto is that off of a standing start (car is in first gear), and I floor it, the Max will utilise all its power because it is able to start off in first.
BUT when I'm already rolling, and I floor it, every now and then the car gets STUCK in second or third and I look like an idiot waiting. and then i floor it again and it downshifts.

I've told my dad about this and he says he notices it sometimes when he has driven it as well. I've check the TSB and there was something on there about an auto tranny problem (2-1 downshifts). But the Nissan guy at the service department did not know anything about it.

JDM4LIFE

iTrader: (2)

yeah, the tranny ecu learns your driving habits, but it also has it's certain points where the torque converter's "busy" and has to change what it's doing to shift gears. not to mention, even if you do like to gun it a lot, you may not realize it, but if you're usually doing it at a certain rpm all the time, and u try to drop it in a completely different rpm range, your car doesn't "remember" you doing that. hence, why it has to figure out what you're doing. and yes, it's sad to say this, but no matter how much us auto-drivers love our cars, a 5-speed is better. maxdrvr847 will run a steady 15.2 with only CAI and eibach springs. that's the only mods. do you people realize how much more effort it takes us to get to a 15.2? it's horrible! besides, our power isn't exactly top notch at lower rpms, stick shifts can launch at 2500 rpms. now, you can always adjust your throttle cable to idle at that rpms, lol, but that's not exactly.....wise.

Adam

gtr_rider

iTrader: (50)

i meant to say that the computer learns the engines behavior than the driver's habits, sorry i was trying to post before everyone got there thoughts in. SPAMMER!!!hehe

brubenstein

TCM's can't learn anything. Torque convertes can't be "busy" because they don't think: there is only the lock-up mechanism that is under computer control. What's faking everyone out is that the TCU (which is hard programed) gets input from several sensors and the ECU, and depending on how the car has just been driven, will effect those sensor readings which determine what the TCU does.
For instance, if you've been sitting in real slow traffic, the underhood temp goes way up, and this is determined in the MAF, and that changes the fuel map used when you stomp on the gas. The sluggishness has nothing to do with the transmission, unless the fluid temp has also gone so high (and thinned out so much) that there is additional slip in the torque converter. This still has nothing to do with its shift programming.

Eric L.

I believe you are correct. If the transmission in 4th gens is truly "driver adaptive" Nissan would have gone to great length to hype it up. I mean, all the other manufacturers make it a point to say their transmissions have "fuzzy logic" (Mitsu), "grade logic" (Honda), "electronically controlled transmission with intelligence" (Toyota's ECTi).

Nissan's is just "electronically controlled automatic transmission." I think the adaptiveness of the Maxima's automatic is to the extent that given an ECU reset, the ECU and TCU remap the shift points. That's it. I think even if you are aggressive in this "learning mode" the ECU will still shift somewhere between 2500-3500 RPM in normal driving.

JDM4LIFE

iTrader: (2)

You're talking about sitting at dead idle at a stoplight of course, while these people are talkin about goin down the road at about 30 or 50 mph and tryin to drop it into 1st or 2nd. You take off from a stoplight, and accelerate like a normal person, and your tranny starts to upshift as it normally would and at that same time u downshift manually, ur car will hesitate because u're trying to make it do the opposite of what you're doing. Not to mention the high temps will also affect the engine much more than what it will the tranny. Also, TCM's do learn. Ever heard of eeprom? Anyways, good post brubenstein. What you were talking about is exactly the reason I plan on (as well as what others should) buying an oil cooler and a tranny cooler. High temps are a bi#$% !!!

Adam

brubenstein

EEPROM's contain firmware and they can be reprogrammed, but only on a chip burner, and/or with an external computer. It is not inherently adaptive. It's the same thing as getting an ECU reprogrammed. You can even get reprogrammed TCU's from places like JWT, but the driver can't teach it anything.

Eric L.

I think while the Maxima's transmission can learn to some extent, it is not truly adaptive like it is on other cars which actually claim to have an adaptive transmission.

When talking about downshifts while the vehicle is in motion, the topic of "shift logic" often comes up. Well, one of the BIGGEST problems with 4th gen autos is that the "shift logic" sucks when it comes to downshifting on a rolling stop. Try this, slow down at a stopsign, and before you completely stop, step on the gas. The transmission will either be in 3rd gear, 2nd if you are lucky. You will literally be accelerating from less than 5MPH in 3rd gear! Now that's lousy shift logic. If the transmission can truly learn, I'd imagine that smashing the gas enough on rolling stops should get it to stick in 1st at least once. But on my car, it hardly ever happens. Chalk it up to Nissan's "adaptive transmission" (or lack of it).

brubenstein

Just because it has logic, doesn't mean you can teach it anything; try talking to a teenager.
If you really want to teach something, get a puppy.

JDM4LIFE

iTrader: (2)

haha, okay, simply put, in all honesty, our automatic sucks! hence why i've already found about 4-5 stick's for sale from salvage yards nationwide. it's gonna cost me about 850 for it, and then i can install it in class. (thank god for the transmission class goin on next semester). any of you had a chance to drive the stick shift with the nissan lsd?

Adam

Daniel B. Martin

Have you ever seen anything in print on this subject? I haven't, but would like to know more on the subject. As far as I know -- today -- the Maxima transmission does not have a learning capability.

MaxedOut97SE

I totally agree, if it were driver adaptble, like BMW (best automatic tranny in the world!!) and Mercedes-Benz, Nissan would be sure to point it out.

dmbmaxima2k2

iTrader: (1)

The only thing I see it doing is constricting the full movement of the pedal. I did at the advisement of my local tuner shop when my car was in for service. It allows the pedal to go down a little further, i didn't notice a dramatic difference or anything but for 30 seconds and for free why not do it.