If your CSV file contains accented characters, typically french words or names, you will get into trouble with Import-CSV.
The reason why the accented characters won’t display properly is that the CSV was saved in ANSI. For example, it’s the default encoding when creating a text file with notepad, Excel generates ANSI encoded CSV file, etc.
An easy fix would be to encode the file in Unicode. This can be done when saving the file with notepad or through PowerShell commands: