Generic OBD-II scanners only scratch the surface when it comes to European cars...

https://list-wiki.win/index.php/Why_Does_My_European_Car_Idle_Change_When_the_Air_Conditioning_Turns_On%3F

Generic OBD-II scanners only scratch the surface when it comes to European cars in Malaysia. These vehicles use manufacturer-specific codes that require specialist diagnostics to pinpoint issues accurately