Any thoughts on the effect of resetting the ECU (the odometer method)on a ECU chip that has been flashed with performance software such as GIAC? I am wondering if you lose or overwrite the tune.Does anyone have an opinion on about resetting before doing a performance flash?

 

The speedo reset/battery disconnect only effects the short term "adaptations" that the ECU stores. It does not effect any custom tunes you might have.

You can also just drive the heck out of it for an afternoon and get the same effect (just a bit slower, but way more fun........ )

 

FWIW, this is confirmation that there's nothing you can do to modify or over-write your performance software by resetting the ECU via the odometer.

 

Haven't been around in a while, but I am very suprised this urban myth is still going on. Resetting the cluster does not reset anything other than the cluster. No short term, long term, DME, nothing. If you must do it. So it with the engine off, then cycle the key afterwards.

 

Please explain and tell us where your info comes from.

 

As 002 stated...it's just a cluster reset, it does nothing to the DME.

 

 

This was confirmed when I got my Mynes tune--they use special software to reset the adaptations, etc. There's no way any combination of button pushing by the owner/driver is going to effect such a seriously low-level reset on the car. You gotta have some big $$ software to accomplish a real reset.

 

So in other words, you can not reset the adaptations by either a dash reset or by disconnecting the battery?

Thanks for clarifying that. Any chance you could post this on the other "viagra" thread?

 

I've been trying to spread the word here for years, so I'm not going any further than this thread. It is fact though. I know this because I am trained to know it and because I have personally tried it while monitoring the adaptations using factory equipment. If you can find a legit description of the cluster tests, you'll understand that the reset is a "cluster reset".

If you still don't believe, try yourself.

More importantly, anyone that has felt a change after doing this should get thier butt dynos recalibrated.
Cheers.

 

Thanks again for the update!

Just to elaborate on the whole "adaptions" thing, what exactly does the ecu learn and how soon can it be "overwritten/updated"?

 

002 is much more knowledgeable on this, but I know enough to know that the Mini ECU is not AI. So it's a dumb computer. It "adapts" by choosing alternate parameters depending upon the values of monitored variables. It "learns" by altering parameter values to changing variables.

Good examples of how dumb it is include:
1. You can tune it to 91 octane gas, but it won't figure out you have filled up with 88 and change parameter values.
2. You can tune it at 3000ft elevation, then drive it to Albuquerque and it will run rich because although it can read barometric pressure, it doesn't adjust the maps (parameter value tables) to give you a higher elevation tune.

I expect more from my iPhone than my ECU, which is not saying much.

 

[quote=DrPhilGandini;2766250]
Good examples of how dumb it is include:
1. You can tune it to 91 octane gas, but it won't figure out you have filled up with 88 and change parameter values.quote]

That's not true. The car is tuned to run 91+ octane. If you go ahead and run 87, it will knock then retard the timing until it stops. once it finds a good spot it will "adapt" by remembering to use X timing at Y temperature at Z rpm at B load. So it's knock adaptation would be X from the base map.

Same with fuel. It starts at a base map and makes adjustments from there. It monitors the 02 sensors and adjusts the mixture. this change is assigned a number that reperesents a delta change.

Adaptations only work within a range and are meant to allow the engine to run well even though there are "worn" parts or manufacturing variances.

People seem to think they are the reason cars run poorly, but it's the opposite. You can go a lot longer without making adjustments or replacing parts because of them. By watching the adaptations you can identify issues and get info on where to look.

 

See, I told you 002 knows a pooter-load about this stuff.
I'm out...

 

There's still a little more to it than that. I couldn't explain it all in a forum, but basically they're good and helpful. I've been able to help at least one member here solve a nagging misfire that was getting expensive to throw parts and fruitless dealer diagnosis at. Knowing the faults and adaptations, plus 15 minutes diagnosis time traced it to a 2 dollar o-ring.

What I can't understand is people want to reset them. This usaully make the car run poorly for a while anyway.

 

Thanks again 002 !

 

really? hahaha...I tot everytime i reset the ecu...I felt the car being a lil more torquey and responsive...

hmmm..i guess you mind will tell you what it wants to tell you huh...

 

If you did a true adaptation reset, you may have felt it be a little more responsive if the starting point was biased towards the lean/advanced side for your set up. Most likely, you couldn't continue to drive at those settings for too long without issue. That's why it would make the adaptation.

When we release a car that has had it's adaptations reset to a customer, we always warn them that it may drive funny for a tank or two.

Now, if only did a cluster reset...

 

I did it (cluster reset?) and the effect was a smoother running car, placebo? who knows

 

exactly.....

 

If you like the result, go for it. Just be sure to cycle the key afterwards. The tach may be out of synch if you don't.

There is a very easy way to test it though. Read the adaptations (fuel trims) using a generic scan tool and record the values. Perform the reset, recheck and compare the values. The results are definitive, but hey it's NAM and the debate is half the fun.

Cheers.

 

it did something, I'm sure, one thing is the computer estimated fuel mileage is now more acurate.

 

What do you mean by this? sorry, English is not my first language...

 

Prior to doing the cluster reset, did you reset your OBC fuel economy at every tank? I think doing the cluster reset zeros out your fuel economy running average, so the average you're seeing now has just been calculated from your consumption since the cluster reset, rather than being averaged out since the last time you reset the OBC fuel economy indicator.

I did the cluster reset a few weeks ago on my MINI (after 50,000 miles), and other than having to reset the clock, I couldn't tell even a slight bit of difference.

 

Sure did