Control FAN individually

Hi Guys. I´m trying to control the FAN of each Extruder individually, but sending M106 P0 S255 turns both fans at 100%. Am I missing something?
Using the SV04 panel is possible to turn just one of them off.

Yes, this is interesting & might be a bug…
The fan control behaviour depends on the print mode you selected:
In both single nozzle modes you can control the fans separately.
In copy, mirror and dual mode a single fan setting sets both fans.
From my point of view it should be different in the dual mode, where it is quite likely to have the need for separate fan settings.
I enclosed my fan test gcode.
FanTest.gcode (782 Bytes)

Like Bjoern said, it depends on the mode.

JohnCarlson’s SV04 FW (search GitHub) is able to adjust fans on the fly to different speeds also, but I only tested it in single mode so far.

Thanks, @Bjoern that didn´t work because I´m using the original SV04 firmware, which all is blocked. I´m trying to upgrade it to Marlin 2.1, and I´m facing issues with the Display DGUS.
I´ll keep trying.

Yes, correct: Displaying M117 gcode messages on the DGUS display is not implemented in Sovol firmware v1.1.0.

You will need either other display hardware / a rotary encoder or an additional DGUS display handling class to get Marlin 2.1.x firmware running. John Carlson did the latter & published his results & matching DGUS software versions.

@Bjoern, thank you for guiding me. John Carlson did an excellent job. I installed it, and it works perfectly. By the way, the visual of the Display is very nice.