Premium brand vehicles, If electronic fault code generated, is it possible to reset to normal without the Techtool or Scan tool ?

It depend on  the vehicle if the fault can be diagnosed visually like part defect, or if can't the scan tool needed.

No it's not possible without the scantool

in some vehicles is possible by removing the battery negative cable for 3 minutes.

Can only be recovered in the case of their return to their manufacturing company

First of, you need to rectify the root cause of the fault code. Once the problem is fixed, it can be reset by using diagnostic tools. Also the vehicle will reset it by itself after 40 startup circle in case the issue is not present anymore. (Depends on the fault location, I mean it is one of the drive train CAN or chassis CAN) For instance fault codes on the body CAN  or telematics wont clear without Diagnostic tool. 

in my opinion I think not, you have always used the tool to rest or to scan the code erased

By Disconnecting  Battery negative cable for one minute will remove all fault code or DTC from ECU memory.

you need the scan tool to reset it.

and for vehicle user electronic messages or reminders some brands need a scan tool to reset them.