can an evo ecu be reset [Archive] - Mitsubishi Lancer Register Forum

can an evo ecu be reset

scandinavian fl
04-12-2007, 19:27
Hi all my neighbour has an ra Scoob. As he bought it used he was unsure of its fueling & what the ecu had learned. He looked into it & found that if you followed a certain procedure with the cars controls you can reset it to the factory default. Can this be done in my uk evo 8 gsr (not 260).

Thanks

Jon M.

AndyF_RSX
05-12-2007, 06:39
Yes, just disconnect the battery for 10 minutes.

Andy

EVOMayhem
06-12-2007, 21:13
Thought it was more like a half hour to an hour?

scandinavian fl
07-12-2007, 18:49
Ian at power engineering told me to give it an hour... I did & know it's perfect!

todd-w
07-12-2007, 20:47
mitsi say ten mins or more

youngsyr
07-12-2007, 20:53
Originally posted by AndyF_RSX
Yes, just disconnect the battery for 10 minutes.

Andy

So, how does this work with ECUFlash and ECUtek?

Surely the settings aren't forgotten after 10 minutes of the battery being switched off? :confused:

grayw
08-12-2007, 05:50
The Eprom is actually flashed and will not change, this contains all the default information the car runs on.
Certain parameters, such as if the car has been knocking and fueling and timing has been reduced, are stored.
Disconnecting the battery will reset these.


Originally posted by youngsyr
So, how does this work with ECUFlash and ECUtek?

Surely the settings aren't forgotten after 10 minutes of the battery being switched off? :confused:

youngsyr
08-12-2007, 08:23
Originally posted by grayw
The Eprom is actually flashed and will not change, this contains all the default information the car runs on.
Certain parameters, such as if the car has been knocking and fueling and timing has been reduced, are stored.
Disconnecting the battery will reset these.

Cheers, Graham.

johnbanks
08-12-2007, 09:15
I can't disconnect and reconnect the ECU plugs quickly enough to avoid a reset.

youngsyr
08-12-2007, 09:19
If the eprom and certain other parameters are saved even when disconnecting the battery, what do you gain by trying to "reset" the ECU on an Evo?

EVOMayhem
08-12-2007, 10:36
Youngsyr, imagine the scene...

...your crusing about, maybe booting it a bit on the back roads, and woe is me, your cam position sensor works its way loose, and comes off. Well, the ECU will s**t itsef as it aint getting the right signal, and it kills the engine to save any damage. You coast to the side of the road, and try restarting the engine, and nothing, its dead. Thats down to the ECU, a built in safety if you will. You would need to reset the ECU to get around this, so theres one of many reasons why you would need to reset an ECU.

I know this situation, as its happened to me before, and I needed to fix the sensor, then reset the ECU before she'd fire up again.

davej
08-12-2007, 16:07
OK so now i'm confused, an Ecutek/Ecuflash reprogams the existing eprom/ecu, this information is now what the car sees as its operating parameters, if you disconnect the battery for 10 mins+ all the ecutek/flash data will be lost and would revert to standard settings as per initial production?

So you would need it reflashed to get those opdated operating parameters back?

amazingjames
08-12-2007, 16:14
Or ypour engine detects knock and poulls the timing back a little and will keep it there til you reset it.The actual map on it will remain on there it just forgets what it has learnt about the fuel and the temp etc running conditions.The standard ecu is a very trick bit of kit and not really worth binn9ng in favour of standalone unles you have loads of mods or going for big power although some people dont believe this and bin it too early in the tuning stage thinking its a wise move when really its a waste of cash and if anything your losing out as the ecu has many fetures that you dont realise and take for granted

grayw
08-12-2007, 16:17
Once the ECU has been flashed by ECUTEK/ECUFLASH it is permanent until ecutek/ecuflashed again.

When you disconnect the battery/ecu you loose the short term stored data, such as octane flag, fuel trims ect. You may have to make it re-learn idle as in the owners handbook.



Originally posted by davej
OK so now i'm confused, an Ecutek/Ecuflash reprogams the existing eprom/ecu, this information is now what the car sees as its operating parameters, if you disconnect the battery for 10 mins+ all the ecutek/flash data will be lost and would revert to standard settings as per initial production?

So you would need it reflashed to get those opdated operating parameters back?

grayw
08-12-2007, 16:21
Almost, the ecu will adjust fuel and timing back to normal after it has been pulled, if it detects knocksums of 3 or less.


Originally posted by amazingjames
Or ypour engine detects knock and poulls the timing back a little and will keep it there til you reset it.

davej
08-12-2007, 16:38
So if it was running rough, you could concievably disconnect the battery to allow the short term data to be lost, reconnect and the Ecutek/Ecuflash data will then be operating as was mapped with just a idle issue to relearn.

I thought it was strange the other way as when i got mine the battery went flat every 2 weeks but never affected how my car drive once i had charged it again and it took me 2 months to find that the stereo wiring was wrong.

Soon as i changed the stereo it was fine, hence my confusion :blush:

Thanks Gray

cossie1
08-12-2007, 16:48
Std map or Ecutek / ecuflash data is stored in flash eeprom.

This is secure memory which will not be erased by powerloss.

The settings it learns (idle etc) are stored in ram. Which like a pc, once power is lost, it forgets everything.

scandinavian fl
09-12-2007, 11:11
I replaced the HKS filter & put a walbro pump on. It would cut out at idle sometimes. I reset the ecu, It's fine now.

Jon M