Tesla Powerwall System Alerts

Alerts a Powerwall system raises about its own components, as listed in the System Alerts section of the Netzero app, with the share of systems reporting each one.

Tesla does not publish definitions for these codes, so the titles and descriptions are inferred from the code name and the component reporting it. Informational states, routine self-tests and fleet-wide noise are left out. Each condition is listed with the codes firmware reports for it. The index segment in a component code (the a078 in PWS_a078_AfciSvmTriggered) changes between firmware releases, so one condition can carry several codes.

System Controller

Alert Description Share of systems
Firmware update failed
FWUpdateFailed
A firmware update did not complete. 1.5%
Lost communication with a Powerwall
BatteryComms
The system controller lost contact with a Powerwall. 1.5%
Powerwall disabled
BatteryDisabled
A Powerwall is disabled and not in service. 0.9%
Battery calibration requested
CalibrationRequested
A battery calibration has been requested. 0.6%
Energy optimizer retrying
OpticasterRetry
The optimizer that schedules charging and discharging failed and is retrying. 0.4%
Grid protection trip
IEEE1547Trip
The system tripped offline because grid voltage or frequency left the limits set by the utility's grid code. 0.4%
Lost communication with the solar meter
SolarMeterComms
The system lost contact with the solar meter. 0.4%
Battery calibration
BatteryCalibration
A Powerwall is running a routine charge and discharge calibration. 0.4%
Powerwall commissioning time error
PodCommissionTimeError
A Powerwall's recorded commissioning time is inconsistent. 0.4%
Powerwall fault
BatteryFault
A Powerwall reported an internal fault. 0.4%
Powerwall breaker open
BatteryBreakerOpen
The breaker feeding a Powerwall is open. 0.3%
Lost communication with the site meter
SiteMeterComms
The system lost contact with the meter at the grid connection. 0.3%
Solar curtailment configuration error
OnGridSolarCurtailmentEnabledError
Solar curtailment could not be applied. 0.3%
Unexpected grid voltage
UnexpectedGridVoltage
Measured grid voltage does not match what the system expected. 0.2%
Grid code settings not saved
GridCodesWriteError
Grid code settings, the utility's voltage and frequency limits, could not be written to a component. 0.2%
Energy optimizer problem
OpticasterExe
The optimizer that schedules charging and discharging failed to run. 0.2%
Reactive power command timed out
DirectReactiveCommandTimeout
A reactive power command was not acknowledged in time. 0.2%
Contactor controller disabled
ContactorControllerDisabled
The controller that operates the contactors is disabled. 0.2%
Lost communication with the utility server
CSIPServerComms
The system cannot reach the utility server used for grid programs. 0.2%
Lost communication with the revenue-grade solar meter
SolarRGMMeterComms
The system lost contact with the revenue-grade solar meter used for production reporting. 0.2%
Unexpected battery power
BatteryUnexpectedPower
Measured battery power does not match what the system commanded. 0.2%
Grid contactor tripped on a fault
GridFaultContactorTrip
A grid fault tripped the main contactor open. 0.1%
Lost communication with a solar inverter
PVInverterComms
The system lost contact with a solar inverter. 0.1%
Unexpected switch to backup power
UnscheduledIslandContactorOpen
The system disconnected from the grid without a scheduled reason and switched to backup power. 0.1%
System shut down
SystemShutdown
The system shut down. 0.1%
Lost communication with the battery meter
BatteryMeterComms
The system lost contact with the meter measuring battery power. <0.1%
Lost communication with the hybrid inverter meter
HybridInverterRGMComms
The system lost contact with the revenue-grade meter on a hybrid inverter. <0.1%
Control loop timing jitter
HighControlLoopJitter
The control loop is not running on schedule. <0.1%
Islanding controller not responding
IslandingControllerMIA
The controller that manages the switch to backup power is not responding. <0.1%
Site meter current sensor open
SiteMeterOpenCurrentSensor
A current sensor at the site meter reads open. <0.1%
Backup energy running low
OffGridApproachingLowSOE
While off grid, stored energy is low and the remaining backup time is limited. <0.1%
Lost communication with the charger meter
EVSEMeterComms
The system lost contact with the meter measuring the EV charger. <0.1%
Network connection changed
NetLinkStatusChange
The network connection changed. <0.1%
Energy totals irrational
EnergyAccumulatorIrrational
Reported energy totals moved in a way the system treats as impossible. <0.1%

Battery Management System

Alert Description Share of systems
Battery configuration data missing
BMS_a085_Config_Block_Missing
A Powerwall's battery management system reports its configuration block missing. 1.4%

Solar Safety System

Alert Description Share of systems
High-voltage protection fault
PWS_a014_HvpFault
The high-voltage protection board reported a fault. 0.4%
Battery switched off
PWS_a036_BatteryOff
The Powerwall is switched off at the unit. 0.1%
Powerwall software restarted
PWS_a001_SW_App_Boot
The Powerwall software restarted. <0.1%
Rapid shutdown active
PWS_a009_Rsd
Rapid shutdown is active, so power conversion and solar output are disabled. <0.1%
Battery disconnect commanded open
PWS_a069_BiDisconnectCmdOpen
PWS_a071_BiDisconnectCmdOpen
The battery disconnect was commanded open. <0.1%
Locked out at startup
PWS_a061_LockedOutOnBoot
The Powerwall locked itself out during startup. <0.1%
Rapid shutdown fault
PWS_a044_HvpRsdFault
The rapid shutdown circuit reported a fault. <0.1%
Battery voltage irrational
PWS_a045_BattVRationality
Measured battery voltage does not agree with the other measurements. not seen
High-voltage protection board not responding
PWS_a021_HvpMia
The high-voltage protection board stopped responding. not seen

Power Conversion System

Alert Description Share of systems
AC undervoltage at startup
PCH_a014_basicAcChecksUV
AC voltage was below the limit during the startup checks. 0.2%
Undervoltage trip
PCH_a078_VFTripsUV
The power conversion stage tripped on undervoltage. 0.2%
Unit switched off
PCH_a019_productSwitchOff
The unit is switched off at its own switch. <0.1%
Internal memory writes inhibited
PCH_a074_nvmInhibited
Writes to non-volatile memory are inhibited. <0.1%

High Voltage System

Alert Description Share of systems
Battery module rate-of-change warning
HVP_a046_SW_BRICK_DVDT_PYRO_WARNING
A battery module's voltage changed faster than expected. 0.5%
Battery disconnect warning
HVP_a021_BistableDisconnectWarning
The high-voltage disconnect inside a Powerwall reported a warning. 0.1%

Battery Aggregator

Alert Description Share of systems
Configuration block fault
BAGGR_a014_ConfigBlockHealthFault
The stored configuration block failed its health check. 0.2%
Unexpected number of Powerwalls
BAGGR_a005_NumBatteriesExpectedMismatch
The number of Powerwalls found does not match the number the system is configured for. 0.2%
Battery aggregator not responding
BAGGR_a003_BAGGR_Controller_Mia
The controller that aggregates the Powerwalls into one battery stopped responding. 0.2%
Powerwall not responding to the aggregator
BAGGR_a006_PWS_Mia
A Powerwall stopped responding to the aggregator. 0.2%
Disconnect current reading irrational
BAGGR_a013_BiDisconnectCurrentRationality
Current measured at the battery disconnect does not agree with the other measurements. <0.1%

Inverter

Alert Description Share of systems
Grid impedance too high
PINV_gridResistanceTooHigh
Measured grid impedance is above the limit. 0.8%
Inverter cannot start: safety line not asserted
PINV_cannotEnableHardlineDeasserted
The inverter cannot start because the hardwired safety line is not asserted. 0.3%
Inverter lost communication with the gateway
PINV_can_gtwMIA
The inverter lost its CAN bus connection to the system controller. 0.2%
Grid disturbance detected
PINV_sensedGridDisturbance
The inverter detected a disturbance on the grid. 0.1%
Undervoltage protection
PINV_vfCheckUnderVoltage
The Powerwall inverter detected grid voltage below its configured protection limit. <0.1%
AC undervoltage at startup
PINV_basicAcCheckUnderVoltage
AC voltage was below the limit during the inverter's startup checks. <0.1%
Overfrequency protection
PINV_vfCheckOverFrequency
The Powerwall inverter detected grid frequency above its configured protection limit. not seen

Solar Module

Alert Description Share of systems
Relay coil reading irrational
PVS_RelayCoilIrrationalWarning
A relay coil reading does not match the state it was commanded into. 0.2%
Solar string disabled for safety
PVS_InactiveUnsafePvStrings
A solar string is inactive because it was flagged unsafe. <0.1%

Share of systems whose most recent diagnostics report the alert, counted over systems active in the last 7 days. Each alert is counted against the systems that have the component reporting it, since not every system has every component. An alert that clears between two readings is not counted, so brief events are under-represented. "not seen" means no system reported it at its last reading.

Data last updated: 2026-09-02