Resetting ECU

[si_from_earth]

I have heard a few comments flying about about resetting your ECU by disconnecting the battery for 30 mins. What exactly does this do?
I am curious as my idle is not very stable and seems quite low. Would resetting the ECU sort this?
Any nasty side affects to be aware of?

 

[xxxic3xxx]

not really, it could but i dont think resetting would do a great deal for your idel speed, however its the first thing to do in a bid to fix it