Technical MK1 ECU reset

[MartZ0r]

Need to reset the ECU on my car as the engine seems to be running very lean according to the plugs. they have been changed now but want to reset my ECU aswell and start a fresh. I have the red key im just worried if i clear it, then it might ask me to imput the code by the pedals? also can i drive the car as i would normally after iv cleared it. It is a S55 without rev counter.

Cheers.

 

[Elroy]

I'd like to know this also..

Mine is 75SX, but its all working fine, except the airbag computer..

anyone has a How to - Reset, and know what can go wrong??

 

[Mdeko]

I'd like to know this also..

Mine is 75SX, but its all working fine, except the airbag computer..

anyone has a How to - Reset, and know what can go wrong??

Air bag computer has to be reset by a fiat dealer im afraid. What the origional poster was refering to was resetting the ECU paremeters.

As for resetting the ECU parametersit wont need you to input the codes via the pedals, resetting it (by leaving battery off overnight?) will just reset the parameters so you may have lumpy idle etc.. while it finds the best setting to run with. Its advised not to drive above 4000rpm for the first 20 or so miles (which is difficult if you dont have a rev counter) but dont go above 30 in second, 40 in 3rd etc...

 

[MikeSalt]

Mdeko is right, if you unplug the battery negative terminal for a period of time (not sure how long exactly), the ECU 'forgets' all its settings and fault codes. When it is reconnected, it has to re-learn the engine again, so it will run rough for 20-30 miles while it sets itself up.

 

[MartZ0r]

done it today, left it overnight and already can see an improvment, the car dont seem to jerk as much. did have a problem with the sparkplug cap coming loose and firing on 3 cylinders during the "first" warmup after the ECU was reset so im hoping this hasnt caused a problem with the learning process. But i refitted the cap, overheated the car and waited for the fan to come on twice then turned engine off, then drove it after.

So far so good!

 

[Elroy]

mine has a "problem" which is; below 3000rpm, it runs normal, and from 3000rpm and up, the accelleration has sum sort of a Boost... dont know if its normal?

runs average of 1:14 litre/km.

anyone can tell me??

 

[Elroy]

well.. so.. nobody knows

 

[reddy4bed]

Elroy-the ecu on a mk1 has nothing to do with the airbag, so no-one knows.

Martz-there is nothing really to reset on the ecu, disconnecting it wont do anything apart from allowing any ram to start again. All the calculations for injector settings will be held in nvram, and not diy resettable.
Tony.