Fault Code Reference

Tesla Fault Codes

Tesla Powerwall battery and Gateway. Home battery storage with Powerwall 2 and Powerwall 3 units widely installed across UK solar installations.

31
Fault codes
Device types covered
Inverter (31)

Common fault codes

ALT-01
Breaker Open
Locate Powerwall AC circuit breaker in consumer unit — confirm it is in ON posit…
ALT-02
Device Offline / Gateway Offline
Check Gateway LED — solid green = connected, pulsing green = charging, red = fau…
ALT-03
Backup Failed / No Power During Outage
Check backup reserve: Tesla app > Settings > Backup Reserve. If battery was at o…
ALT-04
Calibration Discharge to 0%
Confirm via app: controlled discharge to 0% then resumes normally. No backup ava…
ALT-05
CT Reading Error — Negative Solar or Grid
Power down system fully before touching CTs. CT label must face toward the sourc…
ALT-06
Follower Failed to Join
Replace field-crimped Ethernet with factory-made patch cable — Tesla specificall…

All Tesla fault codes

ALT-01
Breaker Open
Locate Powerwall AC circuit breaker in consumer unit — confirm it is in ON posit…
ALT-02
Device Offline / Gateway Offline
Check Gateway LED — solid green = connected, pulsing green = charging, red = fau…
ALT-03
Backup Failed / No Power During Outage
Check backup reserve: Tesla app > Settings > Backup Reserve. If battery was at o…
ALT-04
Calibration Discharge to 0%
Confirm via app: controlled discharge to 0% then resumes normally. No backup ava…
ALT-05
CT Reading Error — Negative Solar or Grid
Power down system fully before touching CTs. CT label must face toward the sourc…
ALT-06
Follower Failed to Join
Replace field-crimped Ethernet with factory-made patch cable — Tesla specificall…
ALT-07
LED Indicator Reference
Powerwall LED bar: solid green = ready/operating normally, pulsing green = activ…
Lost Connectivity to Tesla Site Controller
Gateway Lost Cloud Connection
Check the router and the Gateway Wi-Fi or Ethernet link.
Battery Comms
Powerwall Communication Lost
Check comms wiring terminations, polarity and daisy chain between Gateway and Po…
PINV_a010_can_gtwMIA
Inverter Cannot See Gateway (CAN)
Wait 15 to 30 minutes if a firmware update is running, this alert is expected du…
Site Meter Comms
Site / Energy Meter Offline
Check the remote meter has power and is in wireless range of the Gateway.
Grid Outage
Grid Outage, Running on Backup
Confirm whether a real outage exists. If yes, no action, reconnection is automat…
Grid Resynchronization Failed
Failed to Re-Sync to Grid
Verify voltage and frequency at the Gateway terminals are within the grid code w…
Contactor Unresponsive Close
Islanding Contactor Not Responding
De-energise and inspect contactor wiring and any external backup contactor.
Inverter Not Going To Vf
Will Not Enter Backup (Grid-Forming) Mode
Check state of energy, very low SOE prevents grid-forming.
Black Start Failure
Failed to Black Start
Check SOE, restore grid charging first if depleted.
BackfeedLimited
Export Limit Restricting Discharge
Confirm site import and export limits match the DNO approval (G99/G100).
Battery Fault
Powerwall in Faulted State
Note the accompanying PINV_/POD_ alerts in Tesla One before resetting.
POD_w044_SW_Brick_UV_Warning
Battery Brick Undervoltage Warning
Restore charging, close breakers and confirm charge power is reaching the unit.
POD_w031_SW_Brick_OV
Battery Brick Overvoltage
Let the unit sit and self-balance, avoid forcing full charge.
POD_w063_SW_SOC_Imbalance
State of Charge Imbalance
Leave the system online, balancing is automatic and can take hours.
POD_w067_SW_Not_Enough_Energy_Precharge
Insufficient Energy to Precharge
Confirm grid supply to the Powerwall so it can jumpstart.
Waiting for Solar
Asleep, Waiting for Solar
Reduce home load so solar can run the house and recharge.
Powerwall Overloaded
Backup Overload
Switch off high power loads and let the automatic retry restore supply.
Battery Module Fault
Permanent Battery Module Failure (RMA)
Do not repeatedly power cycle. Confirm the alert in Tesla One.
Powerwall Performance Limited
Locked Out, Deep Discharge (RMA)
Verify the alert and capture vitals in Tesla One.
Powerwall Inverter Failure
Inverter Permanently Failed (RMA)
One controlled power cycle to confirm the fault re-asserts.
Breaker Open
Powerwall Breaker Open
Inspect the board for heat damage before touching anything.
System shutdown
External Shutdown (E-Stop / RSD)
Check any external e-stop or rapid shutdown switch is reset.
PVS_a018_MciString
PV String Not Connected (PVS_a018_MciString A-D)
Verify the string DC connectors are fully seated.
No Solar Production
No Solar Output for 24 Hours
Check the solar AC isolator, breaker and RSD devices.
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