u/IngAguirrel

When I installed the new extruder on my K1C 2025 model, I connected the sensor cable to the nozzle MCU and didnt worked.

The cable pins from the DXC filament sensor are swapped because Creality changed the order of the pins in the Nozzle MCU for the 2025 new model.

You need to accommodate the cables from the sensor connector in the correct order:

https://preview.redd.it/633ppf50yaih1.png?width=1600&format=png&auto=webp&s=8630b1a69b7e31f1caa091d1a5ffe66a5859fd2c

https://preview.redd.it/lg3p9f50yaih1.png?width=720&format=png&auto=webp&s=3b9c41f58d005d877d545a9f8b642fe010ffe539

After that, you need to modify your printer.cfg

First comment old sensor settings

#[filament_switch_sensor filament_sensor]
#pause_on_runout: true
#switch_pin: !PD7

Add the new settings for DXC sensor

[filament_switch_sensor DXC]
pause_on_runout: true
switch_pin: nozzle_mcu:PB9
event_delay: 1.5
pause_delay: 0.25
insert_gcode: 
  M118 Filament inserted
runout_gcode:
  M118 Out of filament
  {% if printer.extruder.can_extrude|lower == 'true' %}
    G91
    G1 E-30 F180
    G1 E-50 F2000
    G90
  {% endif %}

[respond]
default_type: echo
default_prefix: 

I got PB9 from Nozzle MCU chip datashet, is the pin number 46 where is connected the signal from filament sensor. Also removed the "!" because with it, the results were swapped.

Save and restart printer and the sensor will work. You can now query in console
QUERY_FILAMENT_SENSOR SENSOR=DXC

And you will get something like this:

https://preview.redd.it/a534eqw2yaih1.png?width=545&format=png&auto=webp&s=7616f9375e861dcb2627e308bed329b603c3ff5e

Note:
To edit printer.cfg in your K1C 2025 model, you dont need a rooted printer, just go to https://app.fluidd.xyz/ or install fluidd in your computer, and add your printer as PRINTER_IP:7125 (example 192.168.33.134:7125) and then you will see the printer.cfg to update it.