How do you reset the ecu of a Clio 2008?

To reset the ECU of a 2008 Renault Clio, first disconnect the negative battery terminal and leave it off for about 10-15 minutes. This will help clear any stored error codes. Reconnect the battery terminal, ensuring it's secure, and then start the engine. Allow it to idle for a few minutes to let the ECU recalibrate.