This guide is for the Elegoo Centauri Carbon 2 Combo specifically, not the original Elegoo Centauri Carbon. Those are two different printers. The original Centauri Carbon is a single-material FDM machine with its own separate error code documentation on this site. The Centauri Carbon 2 Combo is a newer, enclosed printer built around Elegoo’s CANVAS multi-material feeding system, and it uses a different hotend, different mainboard, and a different error numbering scheme than the original Carbon. If you own the plain Centauri Carbon without the CANVAS unit attached to the side, the fixes below for the 1100 and 1200 series codes will not apply to your machine, and you should look for the guide written for that model instead.
On the Centauri Carbon 2 Combo, faults show up on the touchscreen as a numeric code paired with a short plain-English line, for example “Error Code:104, Nozzle temperature sensor disconnected” or “Filament extrusion failed at the toolhead. The filament may be tangled or the spool is jammed.” Write down the exact number before you touch anything. A lot of these codes look similar from across the room (1242 versus 1243, 1251 versus 1252, 1265 versus 1266) but point at different parts of the machine, and troubleshooting the wrong subsystem wastes time and can mask the real problem. If you’re on the phone or in a forum thread with someone helping you, the number matters more than a description like “it’s jammed again.”
The codes below come from Elegoo’s own wiki (wiki.elegoo.com/centauri-carbon-2-combo), which documents this model directly. Elegoo’s error numbering is not fully sequential and not every number in every range is publicly documented, so this index covers the codes Elegoo has actually published rather than guessing at gaps.
Heating and thermistor errors
101 – Heated bed thermistor / heating circuit fault. The bed isn’t reaching or holding temperature correctly. Elegoo’s own troubleshooting starts by letting the bed cool fully, then comparing the displayed bed temperature to room temperature. If the bed reads noticeably colder than the room, the bed thermistor itself is the usual culprit, and Elegoo’s diagnostic path from there moves on to the mainboard indicator light, then the 24V output at the bed control board, before landing on the heated bed or its control board as the last suspect. Start with the cold-bed temperature comparison before opening the case.
102 – Heated bed temperature sensor disconnected. This one is almost always a loose cable rather than a dead part. Power down, open the bottom cover, and reseat the heated bed thermistor cable on the mainboard, checking that the pins in the connector aren’t bent or pushed back. If reseating doesn’t clear it, Elegoo’s next step is swapping the chamber and bed thermistor cables to see if the fault follows the cable or stays with the bed, which tells you whether the bed or the mainboard is at fault.
103 – Nozzle heater / CAN bus fault. The message reads “please troubleshoot the printhead and wiring.” With the printer powered on and the nozzle heating, manually move the toolhead and watch whether the error flickers on and off. If it does, the CAN bus cable running to the toolhead has a bad connection. If moving the toolhead doesn’t change anything, the next suspects are the ceramic heater cartridge itself (check for a cracked heater or damaged wiring) and the tool head heating interface board connector.
104 – Nozzle thermistor disconnected. Power off, pull the tool head front cover, and reseat the hotend thermistor cable. If the code comes back after reseating, the thermistor itself has failed and needs replacing.
205 & 206 – Chamber temperature sensor disconnected or shorted. These only apply to Centauri Carbon 2 Combo units, since the chamber thermistor is a standard feature on this model (it’s an optional add-on on some other Centauri 2 variants). Elegoo’s fix path is to reseat the chamber thermistor cable on the mainboard first, then test its resistance with a multimeter (roughly 100 K-ohm at 25°C on the NTC100K sensor these use), and if that reads normal, swap the chamber and bed thermistor cables to isolate whether the sensor or the mainboard is bad.
Motion, homing and bed leveling
304 – Z-axis motor error. Watch the homing sequence closely. If the nozzle keeps striking the build plate during homing, the photoelectric limit switch or its mainboard port is the likely cause. If the Z-axis grinds, stalls, or won’t turn at all, the motor, its driver, or its cable are the suspects, and Elegoo’s steps include reseating the Z-axis motor cable and, if that fails, swapping the Y and Z ports on the mainboard to see if the fault follows the port or the motor.
605 – Pressure sensor data error during leveling. Before anything else, check where the printer is sitting. Elegoo explicitly calls out wobbly desks and wheeled tables as a common cause here, since the leveling sensors are strain gauges and pick up vibration easily. After ruling out placement, check whether the bed itself is tilted by comparing the three Z lead screw heights after homing, then check for loose leveling sensor cables under the bed.
704 – Auto leveling failed. This is distinct from 605 in that it fires specifically during the auto-leveling pass rather than as a general sensor fault. If Z-axis homing itself is misbehaving, that’s actually error 304 wearing a different hat, so check homing first. If homing is fine but leveling still fails, check bed tilt the same way as with 605, then run auto-leveling again and watch for the nozzle repeatedly probing or pressing down at one specific corner. Swapping that pressure sensor with its neighbor and re-running the test tells you whether the sensor or the strain gauge adapter board is at fault, since the problem will follow whichever part actually failed.
Cooling fan errors
701 – Mainboard fan error. Reseat the mainboard cooling fan cable first. If the fan still won’t spin after heating the nozzle, check whether the mainboard’s indicator light for that port comes on. A lit indicator with a dead fan means the fan needs replacing; no indicator light points at the mainboard itself.
702 – Heatbreak fan error. Open the tool head, pull the heatbreak fan assembly, and physically check the blades for jammed filament dust or debris before assuming the fan has failed electrically. Preheat the nozzle to around 50°C after reconnecting to confirm the fan spins up.
703 – Model (part) cooling fan error. Same starting point as 702: check for obstructions in the blades first. If a multimeter is on hand, Elegoo gives specific voltage checks at the fan port on the extruder communication board (24V, 3.3V, and 2.3V at three marked pins) to tell whether the fan or the communication board is the actual failure.
Mainboard and communication errors
801 – Extruder-to-mainboard communication error. This is a CAN bus fault between the tool head and the mainboard, separate from the CAN bus issue that shows up as error 103. Reseat the CAN bus cable at both the tool head end and the mainboard end first. If it persists, a multimeter check of the forward voltage at the tool head communication board (around 0.58V) and at the mainboard (around 0.66V) narrows down whether the cable, a board, or the mainboard itself is at fault.
802 – Leveling sensor control board communication error. This is a different fault from 605 and 704, since it’s specifically about the mainboard losing communication with the pressure sensor adapter board rather than getting bad readings from it. Start by reseating the adapter board cable where it connects at the bed and again at the mainboard.
CANVAS enclosure vent (grating) errors
The Centauri Carbon 2 Combo has a motorized exhaust vent, referred to in Elegoo’s documentation as the grating cover, that opens and closes automatically depending on what material you’re printing.
1101 – Exhaust vent failed to open. Elegoo’s diagnostic splits on whether the cover opens at all when the printer powers on. If it doesn’t move, check whether the small magnet on the servomotor has come loose, since that magnet is what the servomotor detection board reads to confirm position. If the magnet is intact, reseat the servomotor detection cable next.
1102 – Exhaust vent failed to close. Elegoo’s own test here is to slice a model with ABS selected as the material and print it, since that’s what triggers the vent to close automatically. If the vent won’t close during that test, check for physical obstructions first, then the servomotor cable.
CANVAS multi-material feeding errors
This is the section that’s genuinely unique to the Combo model. These 1200-series codes cover the CANVAS unit’s own filament path, separate from the base printer’s toolhead and hotend, and they don’t exist on the plain (non-Combo) Centauri Carbon 2 or the original Centauri Carbon at all.
1211 – CANVAS filament runout. The screen prompt is literally “Insert filament into the same slot on CANVAS and tap Continue.” Check the PTFE tube feeding out of the top of the CANVAS unit. Empty tube means the spool actually ran out. If there’s still filament in the tube, the filament likely didn’t seat correctly into the CANVAS feed channel and needs reloading.
1220 – Abnormal filament detected in extruder. This fires when filament is sitting in the tool head and tripping the runout sensor, but the CANVAS unit’s own gripper never grabbed the far end. The fix involves removing the 4-in-1 hub and manually feeding a fresh strand through, then releasing the CANVAS’s internal spring mechanism by pressing the PTFE tube backward to eject the stuck piece.
1231 – Filament cut failed. The CANVAS system uses an automated cutter to trim filament between color changes. Check that the cutter striker block on the lower right of the printer hasn’t come loose or shifted, since that’s the most common cause. Press the cutter handle on the print head by hand to confirm it moves smoothly and springs back; a cutter that doesn’t rebound needs replacing.
1241 – Loading error. Usually a loose PTFE tube rather than a mechanical failure. Reseat the tube at both the tool head end and the CANVAS end, and check the connector on the filament detection board while you’re in there.
1242 – Filament feed from CANVAS to extruder failed. The filament didn’t reach the tool head’s detection sensor within 30 seconds of a load command. Test a different CANVAS port first. If the other three ports work fine, the problem is isolated to one feed channel (check for a tangled or thickened filament tip, or reseat that channel’s feed assembly). If all four ports fail, the issue is downstream in the 4-in-1 hub or the tool head gearbox rather than in CANVAS itself.
1243 – Filament extrusion failed at the toolhead (clog). Before disassembling anything, confirm you have the correct hotend installed. Elegoo is explicit that the Centauri Carbon 2 series and the original Centauri Carbon use different, non-interchangeable hotends, which makes this a real risk if you’ve swapped parts between machines. Also check that Filament Ramming is disabled in Elegoo Slicer, since Elegoo notes that setting can trigger this exact code. If the hardware and slicer settings check out, look for a tangled spool, then gearbox gear tension, then an actual nozzle clog.
1251 and 1252 – Filament fails to unload from the tool head. Both codes describe the same underlying symptom (filament stuck partway through an unload) but Elegoo documents them as separate pages with slightly different diagnostic paths, so check the code number on your screen rather than assuming they’re identical. Start by checking the PTFE tube and 4-in-1 hub for a snapped-off piece of filament, which is the most common cause of both.
1263 – Filament extrusion failed, tangled or jammed spool. This is the deepest troubleshooting entry Elegoo publishes for the Combo. It walks through checking the spool for tangles, measuring filament diameter with calipers against the manufacturer’s tolerance, testing whether filament passes cleanly through the CANVAS feed channel, and only then moving into the tool head gearbox tension and interior. Do the simple checks (tangled spool, out-of-spec filament diameter) before opening the gearbox, since Elegoo’s own flow treats gearbox disassembly as a last resort.
1265 – Filament detection failed at the toolhead, possible jam. Test other CANVAS ports first the same way as with 1242. If only one port triggers it, the feed/extrusion assembly on that channel is the likely cause. If it happens on every port, the tool head’s filament detection board itself is more likely at fault.
1266 & 1267 – Abnormal filament trigger detected at the toolhead. The on-screen message tells you to check and clean the filament path in the tool head and PTFE tube before resuming. If that doesn’t clear it, the fix is reseating the filament detection board’s connectors, and replacing the board if reseating doesn’t help.
Network and cloud errors
2002 & 2003 – Cloud connection / initialization failure. These aren’t printer hardware faults. 2002 means the cloud service couldn’t be reached; 2003 means the printer couldn’t pull its initialization data from Elegoo’s servers. Restart the router and printer first, then check for firmware and slicer updates. Elegoo also recommends toggling LAN-only mode on and back off, and if the printer still won’t connect, testing it on a phone hotspot to rule out your home router. A factory reset with a careful re-selection of time zone is further down the list, since a wrong region setting during initial setup is one of the causes Elegoo lists directly.
When to stop troubleshooting and contact support
A few signals mean it’s time to email Elegoo support at 3dp@elegoo.com rather than keep disassembling the printer. If a code keeps coming back after you’ve reseated every connector Elegoo’s own guide names for it, if you’re being asked to measure voltages you don’t have a multimeter for, or if the fault is inside the gearbox and the gears themselves look damaged or won’t grip filament even after cleaning, stop there. For most of the CANVAS-specific codes Elegoo asks for a video showing the fault happening, the printer’s serial number off the label near the power switch, and the firmware version from Settings, so gather those before you write in. It saves a round trip and gets you a useful answer faster than describing the problem in words alone.
Research notes
Every code and troubleshooting step in this guide comes from Elegoo’s own wiki at wiki.elegoo.com/centauri-carbon-2-combo, which is the official documentation source for this specific model. That wiki page groups Centauri 2, Centauri 2 Combo, Centauri Carbon 2, and Centauri Carbon 2 Combo together under one hub with a model comparison table, since they share a numbering scheme and much of the same hardware. Codes in the 1100 and 1200 ranges (the exhaust vent and CANVAS feeding faults) are confirmed CANVAS-specific and do not appear on printers without that unit. Elegoo’s own documentation confirms the Centauri Carbon 2 series uses a different hotend than the original Centauri Carbon, so hotend-related fixes are not interchangeable between those two guides even where the surrounding steps look similar. Elegoo’s public error code list for this model is not exhaustive. Codes in some ranges (for example, 601 through 604, or numbers between the documented 700-series entries) were not found published on the wiki as of this writing, and Elegoo’s numbering isn’t sequential, so absence of a code here means it isn’t publicly documented yet, not that it doesn’t exist.