H2D: extrusion motor overloaded (0300-0900-0002-0001) or one nozzle stops extruding

Symptom

The H2D pauses the print with an alert saying the extrusion motor is overloaded and that the extruder may be clogged or the filament stuck in the toolhead, or one of the two nozzles extrudes nothing even though no error appears (it may also report air printing).

Likely causes, from most to least likely

1. Hotend not secured: if the retaining clip is not properly closed, the hotend drops and scrapes the bed on the first layer.
2. The part has lifted (warping) and the nozzle hits it.
3. Fully or partly clogged hotend, or a temperature far below what the filament needs (for example a G-code file with mismatched temperatures).
4. Maximum volumetric speed meant for the high-flow hotend used with the standard one: for PLA Basic it is 25 mm³/s on the standard hotend and 35 mm³/s on the high-flow one.
5. Undried PVA or PVA on one nozzle while the other prints PETG, or TPU leaving carbonised residue inside the hotend.
6. Deformed or out-of-spec filament stuck in the extruder, the idler arms or the filament guide.

Checks to tell which one it is

• Note whether the error appears on the first layer and whether the nozzle is pressed against the bed.
• Press «Retry» with the toolhead over the purge area: if it extrudes fine, the resistance is upstream of the hotend (spool, tubes or tangles).
• Check that the hotend temperature when the error appears matches the filament.
• Swap the left and right hotends or try the spare hotend: if the error follows the hotend, that hotend is the clogged one.

Before you start

Before taking anything apart, cleaning or adjusting it, switch the printer off and unplug it, unless a step says otherwise, and do not touch the nozzle, the heater block or the bed until they have cooled down. If in any doubt about electricity, heat or moving parts, stop and ask a professional.

Step-by-step fix

1. Check hotend retention and the bed

   Cancel the print and wait until both hotends are at room temperature. Remove the silicone sock and check that the retaining clip is fully closed and the hotend seated; if not, refit it. Then level the bed and, if it still scrapes in some areas, do the H2D manual bed tramming.

   Check: The first layer prints without the nozzle scraping the plate.

   If that does not fix it: Check the print settings (next step).

2. Slicer settings and temperature

   Check that the profile's maximum volumetric speed matches the type of hotend fitted and that the hotend temperature suits the filament. If you print from a G-code file, check that its parameters match the actual filament and hotend.

   Check: The error does not return during purging or printing.

   If that does not fix it: Remove the hotend and clear its inlet (next step).

3. Remove the hotend and clear the inlet

   With the hotend at room temperature, cut the filament with the cutter: never while hot, because the cutter can jam. Remove the silicone sock, heat to 100 °C (for PLA) and take the hotend out while hot wearing heat-resistant gloves. Pull the stuck filament out of the inlet with pliers, refit the hotend and load again.

   Check: Printing works normally again.

   If that does not fix it: Unload the filament by hand (next step).

4. Unload by hand and improve cooling

   Release the PTFE tube by pressing the black ring, cut the filament and remove the hotend and sock. Push the left idler arm firmly to the left and pull the filament upwards; cut off the deformed section. To stop it happening again, Bambu Lab advises printing with the front door and top cover open and the toolhead front cover removed.

   Check: Once reassembled, the gear turns and filament comes out of the nozzle.

   If that does not fix it: If the gear turns but nothing comes out, unclog the hotend using the H2D procedure; if it does not extrude even without the hotend, the clog is inside the extruder and the filament guide must be removed following the Bambu Lab guide.

5. PVA and TPU

   Always dry PVA before use, even when new (Bambu Lab gives 85 °C for 12 hours in a convection oven), and do not use it on one nozzle while the other prints PETG: if you need PVA supports for PETG, use only the right nozzle with the AMS. With TPU, do a cold pull before each session.

   Check: PVA and TPU prints finish without overload alerts.

   If that does not fix it: Contact Bambu Lab support with the printer logs.

Prevention

• Always check the hotend clip after changing a hotend and level the bed again.
• Do not use a 0.2 mm nozzle for PVA: the clog risk is high.
• If clogs keep happening, print with the door and top cover open to cool the extruder.

Still not fixed?

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Printers it applies to

Bambu Lab H2D and H2D Pro.

Official sources

This guide summarises the official documentation linked here:

• Extruder Motor Overload Error Troubleshooting Guide · Bambu Lab
• How to Check Which Part is Clogged in H2D · Bambu Lab
• H2D Pro · Bambu Lab