Install Guide for Ender 3 V2 Filament Runout Sensor

Product Link 


Install Time: 20-30 Minutes


Mount Installation: 

The product included bracket which replaces stock original left hand sided Extruder Mounting Plate as shown in below photo. It best to removed the X gantry and replaced the bracket while not attached on z axis rod. 

Remove the three bolt as shown below and reinstall the provided back plate. [If you find you a bolt instead of nut, please head further down for guide to find hidden nut]



If you find you have a bolt instead of three nut as shown in below photo, you may need to remove the whole plate from X extrusions as shown in below photo removing the 2 bolts[Square Box] and reveling the hidden bolt.

Cable Installation:

Plug the header with sticker into filament sensor. 

Plug the unlabeled plug directly into motherboard. On a stock Ender 3 V2 board it should be between hotend wire and x axis limit. It should only go in one way, as it keyed connector. 



Once everything is plugged back, you will need to update motherboard firmware. 

You will need to flash updated firmware to ensure filament runout is functional.  Official firmware source [


There is 2 version, please download and install the applicable mainboard hardware revision 4.2.7 or 4.2.2 board. 



Ender-3 V2-Marlin-2.0.1-HW-4.2.7-mainboard-V1.1.2-compatible with BLTouch and filament

Ender-3 V2-Marlin-2.0.1-HW-4.2.2-mainboard-V1.1.2-Compatible with BLTouch and filament

If you need assistance with Bigtreetech firmware, please contact us as it varied between boards and printers.



 Firmware Install Video: 


Final Note:

Once everything is backed and running again, re-level bed and preform initial test print. 


Other Notes: 

The filament sensor should light up blue when a filament is feed through it. 


Note: Please avoid pulling filament out the opposite direction, in rare cases it may result in limit switch to dislodge on certain units or you can print and install this simple filament mod below. [All DREMC-STORE orders Includes Filament switch fix] 

3D Printed Part: