Being a man of science (with a lead foot), I would love to know the truth about the ECU. Even with as much credibility as I can lend to the "seat of pants" and "butt dyno" techniques, I can't make a reasonable argument as to why this should be done.

Why would the manufacturer have such a thing in place, knowing it would de-tune modifications within a few weeks or months? Some reports even say that even non-modified cars have had great improvements in acceleration and throttle resonse when resetting the ECU. Why in the world would a manufacturer do that? Is it some side-effect of an alternate reason for such a learning program?

Does anyone have real data on this? It would go a long way in lending credibility to such a touchy-feely, currently butt-dyno-only observed phenomenon.


03.5 Coupe - Black/Willow, 6MT, Premium, Navi, Aero, Sat

 

Could the butt-dyno observations be more affected by resetting the 'stupid' uh, I mean smart tranny? I drive a lot of highway miles on my commute. When I take the G into stop and go city traffic, it's a slug. I do notice that when I have disconnected the battery for mods or whatever, the tranny is much sharper, which may lead to the butt-dyno observations. Just my .02

 

Being a man of science myself, i'm a sceptic as well. I think it's in everyones heads. I need to see real world numbers, dynos, hell i'd like to see someone extract the data off of one of the chips in the ECU. Some factual information?

 

I agree 100%. All this, "seems to work" or "oops, that just puts it in diag mode, not a true reset" or "rub your belly and sing the smurf theme as you push the gas" crap seems pretty fishy. Has anybody seen anything official or talked with their Infiniti service dept? I just recently passed my break in so I don't plan to do this soon, but will try the battery disconnect just to see. If it seems to make a difference I'll investigate it with my dealer, but has anybody else already done this and have official instructions and reasoning?

Seems too voodoo for me. Anybody have real facts?

2003.5 Sedan Black/Black w/ sport, premium, aero, and winter packages.

 

It was very obvious to me something had changed after I did the "easy" reset.

 

I have not personally tried the Easy Reset, only the battery disconnect. Yes, the battery disconnect does give me a much sharper reaction in the car. Then again, that's my butt-dyno speaking. The first time I did it, I didn't want it to work because it would have been annoying, but it did.

What do you think those "sport" buttons do on other cars? They essentially turn off the adaptive ECU and makes it forget about being efficient and shifting when it's learned. Flushing its memory does the same... Read up on the ECU threads and you'll find plenty of explanations that detail why erasing the memory of an adaptive ECU will result in a crisp, new ride.

Here is an excerpt:
[/i]As far as the ECU goes, it learns off the sensor inputs. If you are always short shifting, it will learn that and back off the timing and pulse width for better fuel consumption. I have seen Maximas that added Y-pipes and saw no change in preformance. Even on the dyno, they didn't show the expected numbers. Then the ECU was reset and they picked up 12 hp at the wheels. Lazy drivers will get a lazy car.[/i]

The theory behind it is sound, and since that is all science is (there are no absolute laws [img]/w3timages/icons/wink.gif[/img]), I'd hope this helps in the quest...

G

2003.5 Black w/ Willow G35
Premium / Sport / Aero / Winter / Navi / Tint

 

Does this propose that if you drive aggressively at times that an ECU reset will be unnecessary? If not, I continue to find it hard to believe that this side-effect is known and tolerated by the manufacturer without notice or solution to the customer.

Regarding science, theory is only 1/10 of it. The rest is all about the data you collect to prove or disprove your theory. In this case, we seem to be missing any real data at all. Everything I have read so far has been subjective observations.

Regarding the battery-disconnect ECU-reset, I'm assume the Navi pkg. owners need to reprogram all their destinations, maintenance tracking, milage records, in addition to the clock and radio/sat presets?


03.5 Coupe - Black/Willow, 6MT, Premium, Navi, Aero, Sat

 

No, it proposes that the majority of data the ECU collects will be "city" driving if you do it, and thus it will affect the ride accordingly. If you drive it aggressively infrequently, that will be only a miniscule part of the data. It's not a "defect" or side-effect. It's what every other auto manufacturer does, pretty much. Everyone uses adaptive ECUs, but some elect to include a "sport" button to turn it off so it shifts more aggresively. I'm not talking about post-modification cars, I'm talking about stock, btw.

Regarding science: I said it is all theory, not laws. Scientists don't like to say it, but there are zero known concrete laws. We may say "well, there's the law of gravity", but a) gravitational fields are not even remotely understood yet, b) the one day we drop and apple and it flies up, everything we've "known" is thrown out the window. Philosophically, science is a lot of theories and data to back them up, but no finite laws. That's what I meant-- I was just being obsetreporous [img]/w3timages/icons/smile.gif[/img] All good...

And as for Navi owners-- You just need to reset your radio stations. That's it. The Maintenance record work off your odometer reading, and that doesn't disappear when you reset the ECU. Also, your destinations, mileage records, address book, etc. stay the same. It doesn't erase anything more than your current mileage (A or B) and radio stations; same as non-navi.

I'll look up some info from Nissan/Inf. to find out more about the ECU. I know I read a post that detailed what the ECU changes in its adaptation with regard to its software, so I'll keep looking. If I know that it retards timings and changes shift patterns after time, and resetting it brings it back to the original state, then that's enough proof for me.

G

2003.5 Black w/ Willow G35
Premium / Sport / Aero / Winter / Navi / Tint

 

Thanks Geo,

I'm at 1800mi now, and in 200 more I'll do the battery disco thing and report back. Mine is manual so I won't be able to monitor shift timing though.

Yea, I know what you mean about science. What hard science calls "laws" are mathematical explanations of observed behavior within a specific set of parameters. Within those parameters, observations made with repsect to these "laws" are incredibly predictable and reliable. Step outside those parameters (near a singularity, approaching the speed of light, quantum size particles, etc) and all bets are off. Science does not imply that when you drop that apple it must absolutely move downward by law, rather that law predicts with incredible reliability that it will.


03.5 Coupe - Black/Willow, 6MT, Premium, Navi, Aero, Sat

 

OBDII cars do adapt and do it fairly rapidly. A reset sets the car back to baseline but it won't take long to adapt. You can also drive the crap out of it and after a few runs it will relearn settings. No need to do the battery deal. This isn't specific to Nissan.It's also why dynos are suspect on OBDII cars.

some references for gearheads can be found by looking for OBDII and adaption.
Here's a good example

http://bimmer.roadfly.org/m3/message...w03/11075.html

 

shader7,

Have you reset your car's ECU?

If not, I suggest you do so and experience the results for youself. That's what the engineering labs were all about. You prove or disprove assumptions, theory or heresay for yourself.

Please provide your impressions once you've completed the experiment. That's what many men of science would do.

DaveO

 

Hiya Dave,

I just disco'd my neg cable a minute ago (before I read your post). I'll post tomorrow about the results from my very own butt-dyno. Do we have assurance that 12hrs is enough? I also only have 1800mi; some reports say that is plenty, some say it takes a couple months to learn to adapt. Already there is a cloud of doubt over this questionable experiment.

The reason I'm skeptical is that with a car such as this, and the amount of resources the car magazines and other independent test labs have at their disposal, it's strange that someone hasn't come out and clearly shown a significant, data-driven conclusion about an ECU reset. This type of phenomenon has great "MEMES", meaning it has great potential to convince people of something they already want, i.e., a performance increase from a simple procedure. Given that the internet makes communication across the globe almost instant, and things like this can nearly instantly become ubiquitous.

If I drive my car tomorrow morning and I feel an improvement then I'll say so, but that observation will still be far from objective. That is the reason important studies (this is far from being a new pharmaceutical release) have strict positive effect guidelines regulated by the government. Blind, double blind, identified, and competitive product testing are all done on real consumers, collecting empirical data throughout the trial in order to prove what they want. It leaves little room for doubt.

As I said, in this case, the only data I have so far is reports from the butt-dyno gallery, and that is a far cry from substantiating any claims in either direction about the ECU reset.

I'll report tomorrow morning, and I'll add my butt to the list.


03.5 Coupe - Black/Willow, 6MT, Premium, Navi, Aero, Sat

 

Shader7,

The Sedan and Coupe ECU programs are different. The Sedan is seriously de-tuned. So the results of your experiment may be different.

I believe the shop manual denotes two methods, one is the accelerator reset, the second is a 24 hour battery disconnect reset. I've done both of these and noted a difference. It's real apparent if you have a CAI.

As a suggestion. For your 12 hour reset, with the negative cable disconnected, turn the key to the "on" position where all the dash light would normally come on. Now depress the brake and accelerator pedals a dozen times or so. Turn the key to off and remove it.

Why? More ju ju? I don't think so, but I could be wrong. With some cars this will bleed the residual power from the ECU and TCU if so equiped. I've done a 12 hour pump the pedals reset and a 1/2 hour pump the pedal reset. All seemed to work based on the way the engine sounded and the transmission shifted.

Were the results subjective? You bet 'ya!

However, after each reset, the throttle tip changed, the engine was more responsive and the air intake was louder for the same accelerator position. The auto transmission also shifted and downshifted with more authority. I wish the dang thing would just stay that way! ECU upgrade here I come!

DaveO