The P1S runs on Bambu Lab’s Health Management System, or HMS, the same fault-reporting framework used across the X1, P1, and A1 lines. When something goes wrong, whether that’s a stalled fan, a bad thermistor, or a filament jam in the AMS, the printer’s screen shows a code in the format XXXX-XXXX-XXXX-XXXX along with a short description and a QR code. Scanning that code takes you to the matching page on wiki.bambulab.com, which is also where this article’s information comes from. Each code breaks down into a module ID (which subsystem raised the alert, such as 03 for the Motion Controller or 07 for the AMS), a part ID, and an alert level: 0001 means an error that halts the print, 0002 is a warning that pauses it, and 0003 is informational only.
Because the P1S shares its mainboard, motion system, and firmware lineage with the P1P and X1 series, most of its HMS codes are identical across those printers, just with different module numbers depending on which parts are actually installed. The P1S does not have the X1 Carbon’s micro-lidar or its high-frame-rate AI camera, so codes tied to module 0C (XCAM) generally do not apply to it. It also lacks an actively heated chamber, so the chamber-heater codes documented for the X1E and H2 series (module IDs in the 0300-9000 range) are not part of the P1S’s normal error set either. Where Bambu’s wiki groups a code under “X1 series” but the underlying hardware, like the heatbed, hotend, or stepper motors, is shared with the P1S, this guide treats it as applicable and says so.
Heatbed and hotend temperature errors
Several codes cover the heatbed’s temperature control loop. HMS_0300-0100-0001-0003, “the heatbed temperature is abnormal, the heater is over temperature,” points to a stuck heating element or a failed temperature reading and typically means checking the heatbed cable and connector before considering a replacement. HMS_0300-0100-0001-0006 and HMS_0300-0100-0001-0007 flag a short circuit or open circuit on the heatbed’s temperature sensor, and HMS_0300-0100-0001-000A points at the AC board itself rather than the sensor. The wiki’s general guidance for all of these is to inspect the wiring first, since loose or pinched cables are the most common cause, and to escalate to a support ticket if the AC board or heatbed unit needs replacing.
The hotend has an equivalent set of codes. HMS_0300-0200-0001-0001 and HMS_0300-0200-0001-0002 report a short or open circuit on the nozzle heater, HMS_0300-0200-0001-0003 means the hotend has gone over its target temperature, and HMS_0300-0200-0001-0009 appears when the printer thinks the hot end isn’t installed at all, which usually means the connector isn’t seated properly. None of these should be printed through. The heater cartridge and thermistor are both field-replaceable on the P1S, and Bambu’s wiki has separate maintenance pages walking through that swap.
Motion, mechanical, and cooling faults
The Motion Controller (module 03) covers stepper motors, fans, and bed leveling sensors. Motor faults follow a consistent pattern across axes: an open circuit (like HMS_0300-0600-0001-0001), a short circuit (HMS_0300-0600-0001-0002), or an abnormal resistance reading (HMS_0300-0600-0001-0003), with the same three fault types repeated for each motor under different part IDs. In practice this points to a loose motor connector or a failed stepper, and the fix is to reseat the cable first before assuming the motor itself is bad.
Bed-related faults are common too. HMS_0300-0D00-0001-0003, and its long list of synonymous codes, means the build plate is not seated properly, often because the plate is warped, has debris underneath, or isn’t clicked fully into the magnetic bed. HMS_0300-0D00-0001-000B and the related HMS_0300-1800-0001-0005 both point to the Z-axis motor getting physically stuck, and the wiki’s advice is to check the Z sliders and timing belt pulleys for anything jammed in them. HMS_0300-1800-0001-0008, “the nozzle touches the heatbed abnormally,” usually traces back to leftover filament residue on the nozzle tip or debris on the plate at the contact point.
Cooling fan codes are more straightforward. HMS_0300-0300-0001-0001 reports the hotend cooling fan running too slow or not at all, which is almost always a stuck fan or a loose connector, and HMS_0300-0400-0002-0001 is the equivalent warning for the part cooling fan. Both are worth checking physically (spin the fan by hand, feel for resistance) before opening a support ticket.
AMS and filament handling errors
Since the P1S is commonly sold and used with the AMS, filament-handling codes under module 07 show up often. HMS_0700-2000-0003-0001 and its counterparts for each slot (0700-2100, 0700-2200, 0700-2300 for slots 2 through 4, and the 0701/0702/0703 prefixes for a second, third, or fourth AMS unit) simply mean a slot has run out of filament mid-print during a color change and the printer is purging the old filament before loading the next spool. No action is needed beyond waiting and reloading the empty slot.
Failed unloads are a separate category. HMS_0700-7000-0002-0004, “failed to pull back the filament from the toolhead to AMS,” fires when the extruder’s hall switch confirms the filament has left the toolhead but the AMS’s internal hub sensor still detects it. According to Bambu’s dedicated AMS loading and unloading troubleshooting page, the usual causes are a PTFE tube bent too sharply above the toolhead, debris built up inside the AMS filament hub, or a spool that isn’t rotating freely because the active support shaft isn’t fully seated. That same page also documents separate fault paths for loading failures, where the feeder’s hall switch does not detect an inserted filament, or where the filament reaches the extruder but the gears fail to grip it, often because of a clogged nozzle rather than an AMS fault. Extruder clogs get their own maintenance article on the wiki rather than a specific HMS code.
Communication, network, and board-level faults
HMS_0500-0300-0001-0001, “the MC module is malfunctioning, please restart the device,” is one of the more disruptive codes because it can knock out toolhead movement, temperature readings, or both, depending on whether the fault is on the transmit or receive side of the AP-to-MC communication link. Bambu’s dedicated P1-series communication troubleshooting guide walks through diagnosing this by watching whether the screen shows a temperature reading and whether directional jog buttons move the toolhead. If neither works, it points to checking the MC board’s status LED, then the MC-AP cable connectors, and finally the AP board itself, in that order.
Board-level electrical faults, covered in Bambu’s “Printer Circuit Failure Troubleshooting” guide for the P1 series, include a completely black screen with no indicator lights, which the wiki attributes most often to a failed microSD card taking the AP board down with it, and a backlit screen with no content, which can be the SD card, the screen cable, or a firmware issue. Network and app-pairing problems are covered separately: the P1S only lists 2.4GHz Wi-Fi networks (not 5GHz), and Bluetooth pairing failures between the printer and Bambu Handy are usually fixed by removing the paired device from the phone’s Bluetooth settings, toggling Bluetooth off and on, and re-pairing. Firmware 01.01.00.00 and later require a full BT pairing handshake during binding that older firmware skipped, which is a common source of confusion in forum threads.
The P1S shares its HMS framework with other Bambu Lab printers. See the Bambu Lab P1P HMS Error Index for the closely related P1P, and the Bambu Lab X1 Carbon HMS Error Index for the codes specific to the X1 Carbon’s lidar and AI camera modules that don’t apply to the P1S.
Many HMS alerts trace back to routine upkeep rather than a hardware fault, so the P1S maintenance schedule is worth checking before assuming the worst. If the code specifically points to the hotend or heater, the nozzle and hotend replacement guide covers what can safely be done at home.