When a charger stops working, the first clue usually arrives as an OCPP message. The charger reports a status such as Faulted together with an error code, and sometimes a vendor-specific code with more detail. Reading these messages correctly saves unnecessary site visits and helps you fix problems faster.
This guide explains the OCPP 1.6 connector statuses and every standard error code, with the typical cause and a sensible first action for each. It then describes a troubleshooting workflow, good practice for remote resets and unlocks, how to set up logging and alerts, and when it is time to send a technician.
- In OCPP 1.6, chargers report status and errors in the
StatusNotificationmessage. - The standard errorCode tells you the category of the problem; the optional
vendorErrorCodeandinfofields often tell you the exact cause. - Check logs and history first, then try the least disruptive remote action.
- Send a technician for safety-related errors, repeated faults, or problems that remote commands cannot clear.
Where OCPP error codes come from
In OCPP 1.6, a charger sends a StatusNotification to the CSMS whenever the status of a connector changes, or when an error occurs. The message contains the connector ID, the status, an errorCode, and optionally a vendorErrorCode, a vendor ID and an info text. Connector ID 0 refers to the charger as a whole.
An error code other than NoError usually comes with the status Faulted, but not always. A charger can report an error, for example WeakSignal or HighTemperature, while it continues to operate in another status. Treat the combination of status and error code as the full picture.
In OCPP 2.0.1, the StatusNotification message is simpler and reports only the connector status. Detailed problems are reported as events through the device model (for example with NotifyEvent). The ideas in this article still apply, but the field names differ.
Connector statuses in OCPP 1.6
| Status | Meaning |
|---|---|
Available | The connector is free and ready for a new session. |
Preparing | A user has started an action, such as plugging in or presenting a card, but charging has not started. |
Charging | Energy is being delivered to the vehicle. |
SuspendedEVSE | The charger is not delivering energy, for example because of a power limit or a local decision. |
SuspendedEV | The vehicle is not accepting energy, for example because the battery is full or the vehicle is scheduling its charge. |
Finishing | The transaction has stopped, but the connector is not yet free, for example because the cable is still plugged in. |
Reserved | The connector is reserved for a specific user. |
Unavailable | The connector has been disabled, for example with a ChangeAvailability command. |
Faulted | An error prevents the connector from being used. |
Two statuses cause many false alarms. SuspendedEV is normal when a vehicle is full or waiting for a scheduled start. Finishing is normal until the driver unplugs. Neither is a fault in itself.
OCPP 1.6 error codes explained
The table lists all standard OCPP 1.6 error codes. The causes and first actions are typical examples; always check the charger manual, because vendors use codes in slightly different ways.
| errorCode | Meaning | Typical cause | First action |
|---|---|---|---|
ConnectorLockFailure | The cable lock did not engage or release | Mechanical lock problem, cable not fully inserted | Ask the driver to reinsert the cable; try Unlock connector |
EVCommunicationError | Communication with the vehicle failed | Vehicle-side issue, damaged cable or plug contacts | Test with another vehicle before suspecting the charger |
GroundFailure | Ground fault or residual current detected | Insulation fault, moisture, faulty vehicle or cable | Do not reset repeatedly; treat as a safety issue |
HighTemperature | Temperature is too high | Direct sun, blocked ventilation, overloaded terminals | Check ventilation and ambient conditions |
InternalError | Error in the charger's hardware or software | Firmware issue or internal component failure | Read vendorErrorCode; try a soft reset |
LocalListConflict | Conflict between the local list and the CSMS | The CSMS answer differs from the local authorization list | Resend the local list from the CSMS |
NoError | No error | Normal status report | No action needed |
OtherError | An error not covered by other codes | Vendor-specific condition | Read vendorErrorCode and info, then check the manual |
OverCurrentFailure | Over-current detected | Vehicle drawing too much current, wiring issue | Check the vehicle and the installation |
OverVoltage | Voltage above the allowed range | Grid disturbance or supply problem | Check the supply; involve an electrician if repeated |
PowerMeterFailure | The energy meter cannot be read | Meter fault or internal wiring issue | Check meter values in logs; plan a service visit |
PowerSwitchFailure | The contactor or relay failed to switch | Worn or stuck contactor | Take the connector out of service; send a technician |
ReaderFailure | The identification reader failed | RFID reader fault or damage | Test with a known registered card; plan a repair |
ResetFailure | The reset could not be performed | Firmware or hardware issue | Try a hard reset or power cycle on site |
UnderVoltage | Voltage below the allowed range | Weak supply, loose connection, grid issue | Check the supply and terminals |
WeakSignal | Weak wireless signal | Poor mobile or Wi-Fi coverage | Improve the antenna position or network |
A practical troubleshooting workflow
- Read the full message. Look at the status, errorCode, vendorErrorCode and info together, and note the time.
- Check the history. Is this the first occurrence or a repeating pattern? Did it start after a firmware change, a power cut or a weather event?
- Check connectivity. If heartbeats stopped, the problem may be the network, not the charger. See our guide to connecting a charger to an OCPP server for common connection issues.
- Refresh the status. Use
TriggerMessageto request a newStatusNotificationand confirm that the error is still active. - Try the least disruptive fix. Unlock the connector, change availability, or perform a soft reset, in that order where it makes sense.
- Escalate. If the error returns or relates to safety, take the connector out of service and schedule a technician.
Remote reset and unlock etiquette
Careless use of remote commands can annoy drivers or hide real problems.
- Check for active sessions first. A reset ends ongoing transactions. Do not reset a charger while someone is charging unless the charger is already unusable.
- Prefer a soft reset. A soft reset restarts the software gracefully. Use a hard reset only when a soft reset fails.
- Unlock only on request. Unlock a connector when a driver reports a stuck cable, ideally while you are in contact with them.
- Do not hide safety faults. Resetting repeatedly after a
GroundFailureor over-current error can put people at risk. - Disable faulty connectors. Setting a connector to unavailable prevents drivers from wasting time on it until it is repaired.
- Record what you did. A log of commands and results helps the next person understand the history.
Üreticy OCPP software supports soft and hard reset, remote stop, unlock connector, change availability, change configuration and TriggerMessage from the dashboard, and every command result is logged.
Logging and alerting
A CSMS should keep the raw OCPP messages, make them searchable, and alert the right people when something goes wrong.
- Raw message logs: the exact StatusNotification payload, including vendor fields, is often the fastest route to a diagnosis.
- Alerts: notify the team about faults, disconnections and commands that did not receive a response.
- Status history: a timeline per connector shows whether a fault is new or recurring.
Üreticy provides searchable OCPP message logs and alerts for faults, disconnections, command timeouts and limit warnings, together with a live dashboard of connector status. See the full feature list.
When to send a technician
- Safety-related errors such as
GroundFailure,OverCurrentFailureor repeated voltage errors. - Hardware failures such as
PowerSwitchFailure,PowerMeterFailureorReaderFailure. - Any fault that returns after a reset, or a charger that stays offline after network checks.
- Visible damage reported by drivers, such as broken cables, plugs or housings.
- Card reader faults that block access; see our guide to RFID card authorization to rule out card problems first.
Give the technician the error codes, vendor codes, timestamps and the remote actions already tried.
Frequently asked questions
What is the difference between status and errorCode in OCPP?
The status describes the state of the connector, such as Available, Charging or Faulted. The errorCode describes a problem, such as GroundFailure or InternalError. In OCPP 1.6 both are sent together in the StatusNotification message.
What does vendorErrorCode mean?
The vendorErrorCode is an optional field in which the charger manufacturer reports its own, more detailed error code. Its meaning is defined in the manufacturer's documentation, not in OCPP. It is often more useful than the standard errorCode for diagnosis.
Is SuspendedEV an error?
No. SuspendedEV means the vehicle is currently not accepting energy, for example because its battery is full or it is waiting for a scheduled charging time. It becomes worth investigating only if a vehicle that needs energy stays in this status.
Should I reset a charger that reports Faulted?
A soft reset is a reasonable first step for software-related errors such as InternalError, provided no session is active. For safety-related errors such as GroundFailure, do not reset repeatedly; take the connector out of service and involve a technician.
Are OCPP 2.0.1 error codes the same as in 1.6?
No. In OCPP 2.0.1 the StatusNotification reports only the connector status, and detailed problems are reported as events through the device model. The troubleshooting approach is the same, but the messages and fields are different.
See every connector status, error code and OCPP message in one place, and act on faults with logged remote commands. Explore Üreticy OCPP software or contact us for a walkthrough.