Mr Merciless

My brother has a Renault Maegane Coupe and recently his heater and A/C stopped working. He took it to the local Renault dealership and they said half the connectors on the ecu have burnt out and he needs it replacing at a cost of about £600.

He can get the part for about £150 from a local parts supplier but Renault warned that if he fits the new ecu himself, the immobilser will no longer recognise his key fob and his car won't start.

Anyone know if this is true?