12602
Easy Fix
Prusa · FDM 3D Printers
Filament Autoload Failed - Sensor Detected Filament But Loading Did Not Complete
Quick Answer
Error code 12602 on your Prusa FDM 3D Printers means: Filament Autoload Failed - Sensor Detected Filament But Loading Did Not Complete. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Cut a clean 45-degree angle on the filament tip and retry loading
2
Remove the filament and open the extruder idler to inspect the drive gears for debris
3
Clean the extruder gears with a brass brush or compressed air
4
Check the PTFE tube path for kinks and replace if the inner diameter is worn or enlarged
5
Adjust the extruder tension spring/screw to the manufacturer-recommended setting
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
Replacement Bondtech drive gears (MK3S+) or Nextruder gears (MK4)
PTFE tube segment
Brass cleaning brush
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