It's about the car Renault Mégane 2/ 2008

@rayayar we do not know what the mechanic checked nor do we know what the diagnosis is. Since you mentioned that it is electrical, use the wiring diagram #5 of the Renault Megane II Wiring Manual Check the fuses that are listed (F2, F5E etc.) as well as power on the steering pump itself. Changing the steering wheel will not resolve this issue.

To check your steering use the Megane 2 Power Assist Steering Fault Finding

@rayayar thank you for posting these codes. Those indicate the following issues:

DF035 - Variable power assisted steering motor - Internal electronic fault

- Intermittent

DF002 ECU 5640 No start assist or sudden loss with DAE fault indicator, STOP indicator and buzzer

Clear the codes using your scanner and see if that helps. There are lots of complaints about these particular errors on the Renault Forums. All of those seem to have issues with needing to reprogram the power steering EEPROM, in common. This may just be something where you want to get a Renault service involved. Of course, you should also try the troubleshooting as shown in the power assisted steering chapter of the workshop manual, as attached in the original answer