Introduction
Use this guide to understand common EV charger fault codes, carry out first-line checks, and decide when to escalate to a maintenance provider. It is written for Fuuse Network Operations agents and for self-service customers who manage their own charging network.
Common EV charger fault codes and what they mean
Fault codes can vary by charger manufacturer, but the examples below cover common issues seen on EV charging networks. Always confirm the exact meaning in the charger manufacturer documentation where available.
| Fault code or symptom | Common meaning | Typical checks |
|---|---|---|
| Connector fault | The connector may not be seated correctly, may be damaged, or the vehicle may not be communicating properly. | Inspect connector condition, cable strain, and session logs. |
| Ground fault / earth fault | The charger has detected an electrical safety issue and stopped charging. | Check for site-wide power issues and escalate if the fault persists. |
| Overcurrent / overload | The charger is drawing more current than expected or protection has tripped. | Review power supply, breaker status, and vehicle demand. |
| Communication fault | The charger may have lost OCPP connectivity or cannot reach the network backend. | Check OCPP logs, network connectivity, and charger status. |
| Undervoltage / overvoltage | Incoming supply is outside the acceptable range. | Check site power quality and any recent outages. |
| Firmware error / device error | The charger may have a software issue, failed update, or internal device fault. | Review firmware version, update history, and restart behaviour. |
Network Operations agent procedure
Use the steps below when investigating a fault reported through Fuuse or by a customer. Record each check and outcome before moving to the next step.
Step 1: Confirm the fault and capture the charger details
Confirm the charger ID, site, connector, fault code, and the time the issue started. Check whether the issue affects one connector, one charger, or multiple chargers at the same site.
Step 2: Check OCPP logs
Review the OCPP transaction and status logs for signs of connectivity loss, rejected messages, boot notifications, heartbeat failures, or repeated error responses. Look for the first event that matches the reported fault and note any pattern of retries or disconnects.
Step 3: Check connector status
Verify whether the connector is available, preparing, charging, suspended, or faulted. Ask site to check for physical damage, debris, bent pins, locked connectors, or cable wear. If the charger supports multiple connectors, compare the status of each one.
Step 4: Check the power supply
Ask site to confirm that the charger has mains power and that site breakers, RCDs, isolators, and local protection devices are in the correct position. If available, review supply readings for voltage, phase imbalance, and recent interruptions. If multiple chargers are affected, treat this as a site power issue until proven otherwise.
Step 5: Check firmware and device health
Confirm the installed firmware version and whether a recent update, rollback, or failed deployment occurred. Check device health indicators, restart history, and any manufacturer-specific diagnostics. If the issue started immediately after a firmware change, compare the affected chargers with a known working unit on the same version where possible.
Step 6: Test and retest
After any corrective action, retest the charger and confirm whether the fault clears. Update the case with the result, the time of the test, and any new log entries.
Self-service checks for network operators before escalating
If you manage your own charging network, complete the checks below before raising a maintenance request. These steps help identify whether the issue is local to the charger, the site, or the wider network.
- Confirm the fault code and note when it first appeared.
- Check whether the problem affects one connector, one charger, or multiple chargers at the site.
- Inspect the charger for visible damage, loose cables, or blocked connectors.
- Check site power, breakers, and any local isolation switches.
- Review recent changes, including firmware updates, network changes, or maintenance work.
- If you have access, review charger logs and backend connectivity status for repeated disconnects or failed sessions.
- Restart the charger only if this is permitted by your site procedures and manufacturer guidance.
When to escalate to a maintenance provider
Escalate the issue to a maintenance provider when the fault cannot be cleared by first-line checks or when there is any indication of a safety or hardware problem.
- The same fault returns after a restart or retest.
- There is visible damage, overheating, burning smell, water ingress, or exposed components.
- The charger has a persistent ground fault, power fault, or internal device fault.
- Multiple chargers on the same site are affected and the issue appears to be electrical or infrastructure-related.
- Firmware recovery, remote reset, or configuration checks do not restore service.
- There is any risk to user safety or site operations.
Information to include in an escalation
To speed up resolution, include the following details when you contact the maintenance provider:
- Charger ID and site name
- Fault code and exact wording shown on the charger or in Fuuse
- Time the fault started and whether it is intermittent or constant
- OCPP log excerpts or screenshots
- Photos of any visible damage or site power equipment if safe to provide
- Any recent changes, maintenance work, or firmware updates
Additional information
If you need help interpreting charger logs or fault behaviour in Fuuse, contact Fuuse Support or your internal Network Operations team. Always follow site safety procedures and manufacturer guidance before carrying out any physical inspection or reset.