Where do these Huawei fault codes come from?

Compiled from publicly available Huawei inverter and battery documentation and field references, then rewritten for the trade. Wattbench is independent and not affiliated with Huawei.

Which of these can I clear on site?

Some clear on their own once grid or environmental conditions return to normal. Anything involving DC isolation, AC switching, wiring or opening the unit is licensed electrical work. Isolate safely, follow AS/NZS 5033 and AS/NZS 3000 procedure and use appropriate PPE before touching a live system.

The exact code isn't listed. Why not?

Firmware and model variants differ, and manufacturers revise their code tables. We document the most common ones; for a variant that isn't here, check the unit's current manual or the manufacturer's service portal.

How current is this reference?

This reference was last reviewed on 3 November 2026. We revise entries when the underlying manufacturer documentation changes.

Inverter Fault Library

Huawei Inverter Error Codes

Huawei SUN2000 alarm reference with audience-separated, source-linked remedies for current M2 and M3 families; broader residential and backup codes remain explicitly unverified for those families.

Sources listedReviewed November 2026Source: Manufacturer documentationOur methodology

Manufacturer: Huawei (SUN2000 series)
Codes documented: 35
Source: Manufacturer documentation
Scope: Reference only

To keep this library for use without a signal, save the Inverter recovery pack. Unsaved, the fault finder still identifies these codes offline, but the fixes are only on this page.

35 of 35 codes

About this fault librarySources · scope

A reference compiled by Wattbench from publicly available Huawei inverter documentation. Source-linked homeowner and installer remedies are reviewed against Huawei's Inverter Alarm Reference (Issue 14), which the current SUN2000-(8KTL–20KTL)-M2 and SUN2000-(20KTL–40KTL)-M3 manuals both point to for their alarms; each family's manual is cited for the models it covers. Earlier issues of those manuals listed 2080 and 2081 for M2 only, and 2003, 2085, 2090 and 2091 for M3 only, so those codes cite that family alone. The four remaining residential-hybrid codes (2068, 2070, 2077, 2082) are not reviewed against either, so they stay searchable with an explicit blank instead of inheriting M2/M3 applicability. Safety note: anything involving DC isolators, AC switches, wiring, electrical measurements or opening the unit is licensed-electrician work. If in doubt, record the alarm and contact your installer.

Key takeaways

35 Huawei (SUN2000 series) fault and alarm codes, documented for the trade.
Compiled from published documentation and field references; Wattbench is independent and not affiliated with Huawei (SUN2000 series).
Codes involving DC/AC isolation, wiring or opening the unit are licensed electrical work. Isolate safely and follow AS/NZS procedure.

Resolution text is manufacturer/service context, not permission for an owner to perform electrical work. Stop at visible observations unless the exact product instructions identify an owner control. Isolation, configuration, testing, opening equipment and wiring are for an appropriately licensed worker and, where required, an SAA-accredited person. Where a card says Product fit is unknown, treat it as brand-level guidance and confirm the exact model, role, regional variant, firmware and current manual before acting.

2001
High string input voltage
The PV array is not configured correctly: too many modules are connected in series, so the string open-circuit voltage exceeds the inverter's maximum operating voltage (cause IDs 1–10). Cause IDs 13–22 name an MPPT (13 is MPPT 1, and so on) whose string open-circuit voltage exceeds the limit at the current altitude.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2001: High string input voltage
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should act on the cause ID. For cause IDs 1–10, with the DC switch on, check the string's series configuration. If its maximum open-circuit voltage is above the inverter's maximum input voltage, contact Huawei technical support; otherwise reconfigure the string so its maximum open-circuit voltage is no greater than the maximum operating voltage, and the alarm clears automatically. If the DC switch is off, contact Huawei technical support. For cause IDs 13–22, check the number of modules in series on that MPPT against the user manual so the open-circuit voltage is within the limit at the current altitude, and check that the altitude is configured correctly.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2002
DC arc fault
The PV string cables generate arcs or are in poor contact. The cause ID names the affected MPPT: cause ID 1 is MPPT 1, and so on.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2002: DC arc fault
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should identify the affected MPPT from the cause ID, check its strings for traces of ignition, poor terminal contact, poor crimping and cable damage, and rectify any fault found. If the alarm persists after that, clear it manually; if it still persists, export the logs and contact Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2003
DC arc fault
The PV string cables generate arcs or are in poor contact. The cause ID names the affected string: cause ID 1 is string 1, and so on.
Product fit · Confirmed · SUN2000-(20KTL–40KTL)-M3
Show field stepsHide field steps for 2003: DC arc fault
Product fit
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should identify the affected string from the cause ID, check it for traces of ignition, poor terminal contact, poor crimping and cable damage, and rectify any fault found. If the alarm persists after that, clear it manually; if it still persists, export the logs and contact Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M3 manual
Manufacturer / escalation handoff
2011
String reversed
A PV string is connected in reverse polarity, or PV+ is short-circuited to PV−. The cause ID names the affected string: cause ID 1 is string 1, and so on.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2011: String reversed
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should wait until the PV string current has fallen below 0.01 A (Huawei's figure), set the DC switch to OFF, then check whether the string's positive and negative terminals are reversed and whether PV+ is short-circuited to PV−, and rectify any fault. If the device fault persists after that, reset it from the app, or turn off the AC and DC switches, wait 5 minutes and turn them back on.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2012
String current back-feed
Only a few PV modules are connected in series in the string, so its terminal voltage is lower than the other strings', or the string has reversed polarity. The cause ID names the affected string: cause ID 1 is string 1, and so on.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2012: String current back-feed
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should check whether this string has fewer modules in series than the strings connected in parallel with it; if so, wait until the string current has fallen below 0.01 A (Huawei's figure), set the DC switch to OFF and adjust the module count. Also check the string for shading, check that its open-circuit voltage is normal, and check for modules connected in reverse polarity.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2021
AFCI check failure
The AFCI self-check fails (cause ID 1 or 2).
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2021: AFCI check failure
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
Turn off the AC and DC switches, wait 5 minutes, turn them back on, then clear the alarm manually. If the fault persists, export the logs and contact your solar installer, dealer or Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2031
Phase wire short-circuit to PE
The phase wire is short-circuited to PE, or its impedance to PE is low. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2031: Phase wire short-circuit to PE
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should check the impedance of the phase wire to PE, locate the point of low impedance and rectify the fault.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2032
Grid failure
The grid has an outage, or the AC circuit is disconnected or its circuit breaker is off. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2032: Grid failure
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time, and check only whether the property has grid supply. If the inverter's AC switch or circuit breaker is off, leave it off: Huawei says it should be turned back on only after the inverter and cable impedance has been checked, which is licensed-electrician work. Contact the installer.
Installer remedy
A licensed installer should check the AC voltage and whether the AC circuit is disconnected or its circuit breaker is off. If the AC switch is off, do not simply turn it back on: check the impedance of the inverter and the external cables first, turn the switch on only if it is normal, and otherwise contact the dealer or Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2033
Grid under-voltage
The grid voltage is below the lower threshold, or the under-voltage duration exceeds the value specified by LVRT. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2033: Grid under-voltage
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
An occasional alarm usually means a temporary grid disturbance, and the inverter recovers automatically once the grid is normal. If it happens frequently, the installer should check whether the grid voltage is within the allowed range and contact the network operator if it is not; change the under-voltage protection threshold only with the network operator's consent. If the fault persists for a long time, check the connection between the AC switch and the power cables.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2034
Grid over-voltage
The grid line voltage exceeds the upper threshold. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2034: Grid over-voltage
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
An occasional alarm usually means a temporary grid disturbance, and the inverter recovers automatically once the grid is normal. If it happens frequently, the installer should check whether the grid voltage is within the allowed range and contact the network operator if it is not; change the over-voltage protection threshold only with the network operator's consent. Also check whether the peak grid voltage is too high. If the fault happens frequently and persists for a long time, contact the network operator.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2035
Unbalanced grid voltage
The three phases of the grid differ greatly in voltage. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2035: Unbalanced grid voltage
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
An occasional alarm usually means a temporary grid disturbance, and the inverter recovers automatically. If it happens frequently, the installer should check whether the grid voltage is within the normal range and contact the network operator if it is not. If the fault persists for a long time, check the AC cable connection; if the cable is correctly connected and the alarm persists and affects the system, contact the network operator.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2036
Grid over-frequency
Grid exception: the grid frequency is higher than the local grid standard allows. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2036: Grid over-frequency
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
An occasional alarm usually means a temporary grid disturbance, and the inverter recovers automatically. If it happens frequently, the installer should check whether the grid frequency is within the allowed range and contact the network operator if it is not; change the over-frequency protection threshold only with the network operator's consent.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2037
Grid under-frequency
Grid exception: the grid frequency is lower than the local grid standard requires. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2037: Grid under-frequency
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
An occasional alarm usually means a temporary grid disturbance, and the inverter recovers automatically. If it happens frequently, the installer should check whether the grid frequency is within the allowed range and contact the network operator if it is not; change the under-frequency protection threshold only with the network operator's consent.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2038
Unstable grid frequency
Grid exception: the rate of change of grid frequency does not comply with the local grid standard. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2038: Unstable grid frequency
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
An occasional alarm usually means a temporary grid disturbance, and the inverter recovers automatically. If it happens frequently, the installer should check whether the grid frequency is within the allowed range and contact the network operator if it is not.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2039
Output over-current
The grid voltage drops sharply or the grid is short-circuited, so the inverter's transient AC current exceeds the upper threshold and triggers protection. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2039: Output over-current
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
The inverter monitors its external conditions and recovers automatically once the fault clears. If the alarm happens frequently and affects production, a licensed installer should check the AC side for a short circuit, and contact the dealer or Huawei technical support if the fault persists.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2040
Output DC component over-high
The DC component in the AC output current exceeds the upper threshold. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2040: Output DC component over-high
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
The inverter monitors its external conditions and recovers automatically once the fault clears. If the alarm happens frequently, contact the installer, dealer or Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2051
Abnormal residual current
The input-to-earth insulation resistance falls while the inverter is operating. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2051: Abnormal residual current
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
An occasional alarm may be a temporary external fault, and the inverter recovers automatically once it clears. If it happens frequently or persists, a licensed installer should check whether the DC-to-earth resistance is too low and rectify any insulation fault.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2061
Abnormal grounding
The neutral or PE cable is not connected, or the inverter's output mode does not match the actual cable connection. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2061: Abnormal grounding
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should power the inverter off (AC and DC switches off, then wait the time on its safety label), check the PE connection and, on a TN supply, the neutral connection and voltage to earth. After powering on, check that the output mode set on the inverter matches the actual cabling.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2062
Low insulation resistance
Cause ID 1: the PV array is short-circuited to earth, or damp air around it has left poor insulation between the array and earth. Cause ID 2: a battery rack is short-circuited to earth or its insulation is poor in a humid environment. The inverter cannot start.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2062: Low insulation resistance
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should follow Huawei's steps for the cause ID. For cause ID 1, Huawei's steps are to set Insulation resistance protection to its minimum value and restart the inverter, check the PE cable, then check the PV array's output-to-earth impedance and rectify any short circuit or inadequate insulation. For cause ID 2, send a shutdown command to the devices on the same DC bus, run the battery rack's insulation impedance detection to locate the fault, check the rack-to-earth impedance and the PE cable, and change the protection threshold only if the impedance falls below it in rainy or cloudy weather.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2063
Over-temperature
Cause IDs 1 and 2: the inverter is installed somewhere poorly ventilated, the ambient temperature is too high, or the inverter is working abnormally. Cause ID 3 adds an obstructed fan airflow or a blocked heat sink. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2063: Over-temperature
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and check only for safely visible blocked ventilation or direct sun. Do not open the inverter; contact the installer if the alarm remains after the unit cools.
Installer remedy
Check the ventilation and ambient temperature at the install location; if ventilation is poor or the ambient temperature is too high, improve ventilation and heat dissipation. For cause ID 3, Huawei also lists an obstructed fan airflow or a blocked heat sink among the causes; its step is to check ventilation and heat dissipation and reduce the ambient temperature. If ventilation and temperature meet requirements, or the alarm persists, contact your dealer or Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2064
Device abnormal
A major fault has occurred on an internal circuit of the inverter. For cause IDs 2–9 and 13–19 the inverter may instead be faulty or protected because of external factors such as the grid. The inverter shuts down.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2064: Device abnormal
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown. Do not reset the inverter or turn any AC or DC switch back on, and keep clear of the front of the unit; contact the installer or Huawei support.
Installer remedy
A licensed installer should act on the cause ID. For cause IDs 1, 10, 11, 12, 20, 29 and 30, do not reset the inverter or turn the DC switch back on. For cause IDs 1, 10, 11, 12, 20 and 29: if the DC switch is off, leave the AC and DC switches off and contact Huawei support; if it is on, wait the same day until the DC current has fallen below 0.01 A (Huawei's figure), turn off the AC and DC switches, disconnect the DC side and contact Huawei support. For cause ID 30, whatever the DC switch position, wait the same day until the DC current has fallen below 0.01 A, turn off the AC and DC switches, disconnect the DC side and contact Huawei support. For cause IDs 29 and 30, do not stand in front of the inverter during maintenance, and if the fault spreads (smoke, fire or an abnormal smell), follow Huawei's emergency plan. For cause IDs 2–9 and 13–19, turn off the AC and DC switches and check the grid harmonics and the insulation of the input and output cables; if both are normal, turn the switches back on 5 minutes later, and contact Huawei support if the fault persists. If the unit looks damaged, turn off the AC and DC switches and remove the DC terminals only after the string current has fallen below 0.01 A.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2065
Upgrade failed / software version mismatch
The update failed (cause IDs 1–7), the communication protocol version is incorrect (8), the inverter is too hot or its DC side is not powered (9), or the optimisers need updating (10). The inverter cannot start.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2065: Upgrade failed / software version mismatch
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID and software version if visible. Do not retry the update, load firmware or operate the AC or DC switches, even if the cause ID points to the DC side; contact the installer or Huawei support.
Installer remedy
Retry the firmware update. For cause ID 9, first wait until the inverter has cooled or its DC side is powered; for cause ID 10, update the optimisers. If the update fails repeatedly, contact the dealer or Huawei technical support.
Manufacturer firmware pageHuawei: Not publicly listed; confirm with the manufacturerProduct fit Confirmed
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2066
Licence expired
The authorisation certificate has entered its grace period, or the authorised feature is about to expire. Licensed features are unavailable without a valid licence.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2066: Licence expired
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, inverter indicators and software version if visible. Do not power-cycle, load firmware or alter communication wiring; contact the installer or Huawei support.
Installer remedy
Apply for and load a new certificate through the authorised Huawei workflow.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2067
Faulty power collector
The power meter's communication is interrupted (cause ID 1), or its CT (2) or PT (3) is disconnected from the meter.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2067: Faulty power collector
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, and note whether monitoring or power-flow data is missing. Do not access the meter, its CT or PT connections, RS485 wiring or switchboard; contact the installer if it persists.
Installer remedy
A licensed installer should act on the cause ID. For cause ID 1, confirm the configured meter model matches the actual meter, that its communications parameters match the inverter's RS485 settings, that it is powered on with its RS485 cable connected correctly, and that a grid failure has not cut its supply. For cause IDs 2 and 3, check that the CT or PT is correctly connected to the meter.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2068
Battery abnormal
The battery is faulty or disconnected, or the battery circuit breaker is off while the battery is running.
On this device only. Signed in? Account Jobs still work.
2070
Active islanding
During a grid AC outage, the inverter proactively detects islanding.
On this device only. Signed in? Account Jobs still work.
2072
Transient AC over-voltage
The inverter detects that the phase voltage exceeds the transient AC over-voltage protection threshold.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 2072: Transient AC over-voltage
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, cause ID if shown, and time; check only whether the property has grid supply and allow the inverter to recover. If it repeats, contact the installer; do not change protected grid settings.
Installer remedy
A licensed installer should verify voltage at the grid connection point and its peak value. Contact the network operator if supply is too high; change the protection threshold only with network approval.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff
2077
Off-grid output overload
The off-grid output is overloaded or short-circuited.
On this device only. Signed in? Account Jobs still work.
2080
Abnormal PV module configuration
The optimiser or PV module configuration does not meet the inverter's requirements. Huawei lists 15 cause IDs, including too many or too few optimisers in series, string output reversed or disconnected, parallel strings on one MPPT with different optimiser counts, optimisers moved or strings combined (7), weak or abnormal irradiance (8), string voltage above the inverter's input limit where not every module has an optimiser (9), and optimiser compatibility (10 and 11). Huawei marks the steps for cause IDs 1, 4 and 5 (too many optimisers or strings, string output reversed or short-circuited) as applying only to SUN2000L models.
Product fit · Confirmed · SUN2000-(8KTL–20KTL)-M2
Show field stepsHide field steps for 2080: Abnormal PV module configuration
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, inverter indicators and software version if visible. Do not power-cycle, load firmware or alter communication wiring; contact the installer or Huawei support.
Installer remedy
A licensed installer should check the total number of modules, the modules and optimisers per string and the number of strings against the requirements, and check for reversed polarity, disconnected strings and incorrectly made optimiser extension cables (positive connector at one end, negative at the other). For cause IDs 7, 8 and 15, run the optimiser search again when irradiance is normal; for 15, also measure the string voltages and work through the 'Troubleshoot abnormal string voltage' table in the optimiser user manual. For cause ID 9, calculate the string voltage from the number of modules and check it against the inverter's maximum input voltage. For cause ID 12, connect only one string to each MPPT if the inverter does not support parallel strings. For cause IDs 13 and 14, make sure every module has an optimiser and the series count is within the limit. For cause IDs 10 and 11, use optimisers according to the compatibility matrix in the optimiser user manual.
Remedy sourceHuawei alarm reference SUN2000 M2 manual
Manufacturer / escalation handoff
2081
Optimiser fault
Some optimisers are faulty (cause ID 1, a warning) or damaged (cause ID 2, major).
Product fit · Confirmed · SUN2000-(8KTL–20KTL)-M2
Show field stepsHide field steps for 2081: Optimiser fault
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, inverter indicators and software version if visible. Do not power-cycle, load firmware or alter communication wiring; contact the installer or Huawei support.
Installer remedy
A licensed installer should check the optimiser fault for its cause ID: for cause ID 1, open the optimiser layout in the app to view the fault details (local app: Maintenance > Optimizer layout > Malfunction optimizer); for cause ID 2, contact the dealer or Huawei technical support to replace the damaged optimisers.
Remedy sourceHuawei alarm reference SUN2000 M2 manual
Manufacturer / escalation handoff
2082
Grid-tied / off-grid controller abnormal
The inverter fails to communicate with the Smart Backup Box, or an unrecoverable fault has occurred inside the Smart Backup Box.
On this device only. Signed in? Account Jobs still work.
2085
Built-in PID operation abnormal
The DC-to-earth impedance is low, or an unrecoverable fault has occurred in the internal circuit. Huawei gives separate steps for cause IDs 1 and 2.
Product fit · Confirmed · SUN2000-(20KTL–40KTL)-M3
Show field stepsHide field steps for 2085: Built-in PID operation abnormal
Product fit
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm and cause ID if shown, leave PV, AC and earthing wiring and isolators untouched, and contact the installer. Electrical measurements and recovery work require a licensed worker.
Installer remedy
A licensed installer should act on the cause ID. For cause ID 1, turn off the AC and DC switches, wait the period on the inverter's safety warning label, then turn the DC and AC switches back on. For cause ID 2, check the DC-to-earth impedance and rectify any short circuit or inadequate insulation. If the fault persists, contact your dealer or Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M3 manual
Manufacturer / escalation handoff
2090
Abnormal active power scheduling instruction
The DI input is abnormal, or inconsistent with the configuration.
Product fit · Confirmed · SUN2000-(20KTL–40KTL)-M3
Show field stepsHide field steps for 2090: Abnormal active power scheduling instruction
Product fit
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, inverter indicators and software version if visible. Do not power-cycle, load firmware or alter communication wiring; contact the installer or Huawei support.
Installer remedy
A qualified installer should check that the cables are connected correctly to the DI ports, and that the DI signal configuration table for active-power scheduling is complete and meets the network operator's requirements.
Remedy sourceHuawei alarm reference SUN2000 M3 manual
Manufacturer / escalation handoff
2091
Abnormal reactive power scheduling instruction
The DI input is abnormal, or inconsistent with the configuration.
Product fit · Confirmed · SUN2000-(20KTL–40KTL)-M3
Show field stepsHide field steps for 2091: Abnormal reactive power scheduling instruction
Product fit
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, inverter indicators and software version if visible. Do not power-cycle, load firmware or alter communication wiring; contact the installer or Huawei support.
Installer remedy
A qualified installer should check that the cables are connected correctly to the DI ports, and that the DI signal configuration table for reactive-power scheduling is complete and meets the network operator's requirements.
Remedy sourceHuawei alarm reference SUN2000 M3 manual
Manufacturer / escalation handoff
61440
Monitoring unit faulty
The monitoring unit's flash memory is insufficient or has bad sectors, so it cannot record data.
Product fit · Confirmed · 2 documented families
Show field stepsHide field steps for 61440: Monitoring unit faulty
Product fit
- SUN2000-(8KTL–20KTL)-M2 · Three-phase string inverter
  Confirmed · Manual Issue 20 · AU/region not confirmed · Firmware not documented
- SUN2000-(20KTL–40KTL)-M3 · Three-phase string inverter
  Confirmed · Manual Issue 31 · AU/region not confirmed · Firmware not documented
Safe checks now
Record the alarm, inverter indicators and software version if visible. Do not power-cycle, load firmware or alter communication wiring; contact the installer or Huawei support.
Installer remedy
A licensed installer should turn off the AC and DC switches, wait 5 minutes, then turn them back on. If the fault persists, replace the monitoring board or contact the dealer or Huawei technical support.
Remedy sourceHuawei alarm reference SUN2000 M2 manual SUN2000 M3 manual
Manufacturer / escalation handoff

Sources

ManufacturerHuawei Inverter Alarm Reference, Issue 14 (2026-06-15)
ManufacturerSUN2000-(8KTL-20KTL)-M2 User Manual, Issue 20 (2026-03-30)
ManufacturerSUN2000-(20KTL, 29.9KTL, 30KTL, 36KTL, 40KTL)-M3 Series User Manual, Issue 31 (2026-09-28)

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Good to know

Frequently asked

Where do these Huawei fault codes come from?: Compiled from publicly available Huawei inverter and battery documentation and field references, then rewritten for the trade. Wattbench is independent and not affiliated with Huawei.
Which of these can I clear on site?: Some clear on their own once grid or environmental conditions return to normal. Anything involving DC isolation, AC switching, wiring or opening the unit is licensed electrical work. Isolate safely, follow AS/NZS 5033 and AS/NZS 3000 procedure and use appropriate PPE before touching a live system.
The exact code isn't listed. Why not?: Firmware and model variants differ, and manufacturers revise their code tables. We document the most common ones; for a variant that isn't here, check the unit's current manual or the manufacturer's service portal.
How current is this reference?: This reference was last reviewed on 3 November 2026. We revise entries when the underlying manufacturer documentation changes.

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