How to reset ECU on 2.0 gdi Pinin

[PeterBurgess]

Hi all, does anyone know how to reset the ecu without resorting to disconnecting the battery please?

Poor to non existant idle after changing battery, used power pack to keep power to system but the earth lead fell off for a few seconds when were putting the new battery in The display still registered mpg etc so this hadnt had time to lose its info.

Thanks

Peter