What is up with the ECU??
 

Just a quick easy question.....Why is resetting the ECU under so many posts?? If your gas mileage is not accurate, reset the ECU,,,,If your car surges, reset the ECU,,,,,,,,,Why so much emphasis on this??....I have owned many cars and never reset the ECU.... What if I never reset it....would the performance suffer forever?? Any thoughts??

when you reset the ECU, you reset base line functions. Sometimes programming gets hung up and can effect the readings your O2 sensors are getting and therefore lead to improper A/F ratios and inefficient combustion of fuel.

Now that so many functions in modern cars are computerized, resetting is common practice. Think of when your home computer gets hung up or is running slow or your modem is not working...whats the first thing you are told to do? reset the unit or reboot it.

For example, lets say your data logging of your ECU had you running very rich, unless you reset it, the data just builds on itself and possibly stays in a dysfunctional mode. This could lead to fouled plugs which could lead to inefficient chamber combustion which in turn could lead to cylinder wash down which could lead to ring blowby and fuel contaminated oil. This is an extreme scenario and one that might take some time, but just shows you that it is often better to just reset the ECU and start a new baseline rather than risk anything and run your engine inefficiently! Hope this helps.:biggthumpup:

^^Yep, what he said?

Wow, My old 58' Chevt pickup is looking better every day.......only kidding ....wish I had one.

Is it a good idea just to reset it as a precaution,,,,if so what is the easiest way and if it's not done correctly can it hurt anything??

No need to reset it unless you are getting some kind o computer quirk or glitch. If your getting something like extremely bad fuel mileage, hesitation etc then you can try a reset and see if things come back to normal. JUst to do it for the sake of it is not necessary.:biggthumpup:

you need to reset it when you mod for performance. (intake/exahust)
It will have to re learn for the added air.

Jeez you guys talk like computer programs are some mysterious force of nature. I am a programmer/network/computer engineer, and if infiniti made an ECU that isn't capable of learning/taking in new data and readjusting on the fly, I'd be sorely disappointed. Its not hard to create a program that can correct itself when new data/trends are presented.

Now I still think that resetting the ECU can be beneficial, but I sometimes wonder if its just in our heads. ECU programs in todays world should be capable of fixing itself.

And don't forget, when you turn the car off its like turning your computer off, which is essentially resetting it. The whole moniker of resetting the ECU is not the same as resetting a computer, its actually more like resetting a ROUTER ( by holding it down and making it reflash the rom to default values ), which is usually done when you are having a serious problem and have to resort to resetting the rom and starting from scratch.

Windows XP vs an ECU OS which is a Heavily optimized Real time operating system, is in no ways even REMOTELY comparable.:7:

I think the car industry probably needs to rethink how they design their ECU OS. The fact that adding an intake/exhaust requires a reset is sad. It really shouldn't need that.

well everywhere i have read says reset... besides... what can it hurt?

I won't disagree with that comment. :) I just like proof that an ECU can't learn, and that we aren't just following our fathers advice blindly.

I don't want to start another flame war, but I think the ECU adapts just fine to any intake or exhaust in a couple hundred miles at most. I have no idea where the ECU reset mantra came from, but I do think it's 99% urban legend.

The ECU will relearn after a couple hundred miles... but why wait?

I doubt that it would even take that long. As of this time I'm not an Infiniti expert but am sure the ECU's function very similar to other manufactures. Many things get reset on "two trip logic". Provided that each trip lasts more that just one or two miles and that minimum speeds are obtained etc. the short term tables will be updated. Long term tables are updated on a weighted average of short term tables where more weight is given to the newest tables.

When a ECU is reset the short and long term tables get initialized from default values stored in the eproms by the manufacture. The default values are generally wider in scope and tolerance as compared to what eventually gets learned. Installing a new component that the manufacture has not provided for in the default values actually may initially make the car perform less optimally when a reset is done as compared to no reset and using the values that had been previously learned. It strictly is a crap shoot. The good thing is that the ECU in either case will quickly readjust the parameters.

Good prudence would be to install a modification, reset the ECU if desired or recomended by the designer of the modification, drive the car in a conservative fashion for one of two trips before raising the stress on the engine, transmission or other components.

Well, I am not a computer programmer, but I can tell you from experience that when you turn off your car it is NOT like reseting the ECU. Sometimes things get hung up and it's the only way. I know of many times where a MAF sensor was kicking the ECU into safe mode and limping the car and would not be resolved till the ECU was reset.

I would only reset the ECU if you only get a SES light other then that it should correct itself. Just my .02. Either way reseting or just leaving it alone it will still take a while to teach itself and put things in the right parimeter