EV Charger Communication Error: What It Means and How to Fix It

What Does "Communication Error" Actually Mean?

Before any electricity flows, your car and the charger need to agree on a few things. How much power can the car accept right now? What is the battery's current state of charge? Is the connection safe? This negotiation happens through a digital protocol, usually ISO 15118 on newer DC fast chargers, or basic signaling on older or AC chargers.

A communication error means this negotiation broke down. The charger sent a message, your car did not respond in time, or the response did not make sense to the charger. It could also mean the charger's internal software hit a glitch before the conversation even started.

Think of it like a phone call where one side dials, the other side picks up, but neither can hear the other. The connection exists, but the conversation cannot happen. The charger gives up and shows an error rather than pushing power through a connection it cannot verify is safe.

What Causes EV Charger Communication Errors?

In most cases, the problem is with the charger, not your car. Here are the usual suspects.

• → Charger firmware glitch. Chargers run software, and that software can freeze or behave unexpectedly. A charger that has been running continuously for days or weeks without a reboot is more likely to develop communication issues. This is the single most common cause.
• → Poor cable connection. If the connector is not fully seated in your car's port, the communication pins may not make proper contact. Dirt, ice, or debris in either the plug or the port can also interfere. Push the connector in firmly until it clicks.
• → Charger has not rebooted recently. Like any computer, chargers benefit from a restart. Stations in remote locations or with poor maintenance schedules can go weeks without a reboot. The longer the uptime, the more likely a communication glitch becomes.
• → Network connectivity issue on the charger side. Many chargers need a cellular or wired internet connection to process authentication and billing. If the charger loses its network connection, it may fail during the handshake even though it can physically deliver power. This is entirely the operator's problem, not yours.

How Do You Troubleshoot a Communication Error Step by Step?

If the quick fix above did not work, try these steps in order.

1. Check the connector and port. Remove the connector. Look at your car's charging port for debris, moisture, or ice. Look at the charger's connector pins. Wipe both clean if needed. Plug back in firmly until you hear or feel the click.
2. Lock and unlock your car. Some vehicles reset the charging communication when you lock and unlock from the key fob or app. This can clear a stuck handshake on your car's side.
3. Try a different connector on the same charger. Many DC fast chargers have both CCS and CHAdeMO connectors. If one fails, the other may work because it uses a separate communication path.
4. Move to a different stall. If the station has multiple chargers, try another one. Communication errors are usually specific to one charger unit, not the whole station.
5. End the session in the app and start fresh. If you started the session through an app, fully stop it, wait a minute, then initiate a new session. Sometimes the charger's backend gets stuck in a half-started state.
6. Report the issue and move on. Use the charging network's app to report the broken charger, or call the number on the unit. Then drive to the next available station. Do not keep retrying the same broken charger.

How Do You Know It Is Not Your Problem?

If you tried the steps above and the charger still will not start, it is almost certainly a charger-side issue that only the operator can fix. Some chargers need a remote reboot from the operator's control center. Others need a physical visit from a technician.

The key signal: if your car charges fine at other stations, the problem is not your car. Do not let a single broken charger make you doubt your vehicle. Public charger reliability varies widely by network, location, and maintenance schedule. A communication error is the charger telling you it cannot do its job right now.

Frequently Asked Questions