Reset Engine Management ECU?

[Anonymous]

Hi

Dont know if there is any truth in this as it came up in a pub conversation? - But does anyone know whether you can reset the engine management ecu and also whether there is any benefit in doing so?

Still learning  s:? :? s:?  

Cheers

Mark.

[Liz]

I thought that this reset could be done by disconnecting the battery for 20 mins..I am sure that someone will be along to correct me if I am wrong about that!! I tried it and could not tell any difference.  s:? :? s:?

[so.simple]

Did it yesterday after cleaning the MAF sensor. The difference is subtle but its there. The idle is much more regular, the reaction speed has increased, the whole engine seems a bit more sorted out.

[Anonymous]

You can pull all the ECU fuses instead of disconnecting the battery. Think it is two out of the side compartment by the passenger door and one out of the engine compartment.

See http://www.mr2roc.org/forum/viewtopic.php?t=3439&highlight=reset+ecu for more details and on MAF sensor cleaning.

I have only done this once and to be honest I didn't notice anything. I left the car for an afternoon at work with the fuses out. I had to do it at work as you can't lock the car with the fuses out. Don't trust my neighbour hood.   s8) s8)

[Tem]

I have only done this once and to be honest I didn't notice anything.

Since no one really knows what happens inside the ECU, we're all just guessing here  s8) s8)

My guess is that after the reset the ECU has a base mapping that works just fine for everyone. When time passes, it will adapt the settings a bit based on your driving style. So if most of your driving is in downtown traffic, commuting or just cruising, you will end up with granny settings and reset will actually make the car feel faster/better. But if you have a habit of driving the car fast most of the time, reset will make it more conservative.

That's the only reason I can figure out for dynoing 149hp after using 98 octane and "racing" it all the time and after reset dynoing just 140hp. Go figure, would be nice to know instead of guessing  s:? :? s:?

[Anonymous]

when you disconnect power from the ECU for an extended period of time (10 mins usually) it will revert to cam memory.  then when you reconnect the power it will go into a learning curve re-evaluating all its sensors and efficiencys to best run the engine.  (fuel trim etc)

consequently to gain the most from this you should take the car for a good spirited run when you reconnect the power, it will then take its learning curve from this style of driving.  

any gains will be minimal it has to be said.  its often a good idea to do this if you have recently modified the car in some way, ie filter,exhaust etc, you will then get the best from the car, or at least as much as you can within the limited scope of the basic oem ECU adjustments.

If you reset the ECU in this way and then just start it on tickover and dont actually take it for a drive for a long period of time (days), you can encounter starting problems nad a few other niggles.

[Anonymous]

Cheers All

Cleaned the MAF yesterday and reset the ECU prior to taking the 2 for a run.

Havn't noticed any difference really but its all part of the fun!  s:D s:D  

Mark.