This is general guidance based on U.S. Department of Energy AFDC. Actual charger behavior varies by manufacturer and firmware version. Always follow on-screen instructions and contact the charging network if you are unsure. If anything looks or feels unsafe, stop charging and move away from the charger.
The charger's safety diode check failed during the initial handshake. This is a standard safety check for AC charging (IEC 61851). The charger detected that the vehicle's charging circuit does not have the required rectifier diode, or the diode is faulty.
Seeing this on the charger right now?
- Don't unplug while the charger is active. Wait for the screen to update.
- Try stopping and restarting the session from the charging app or RFID card.
- If the error persists, move to a different connector or charger if available.
Read the full explanation below, or scan the charger screen with EVcourse for instant help.
What to do
- Unplug and retry once
- Try a different AC charger
- If this happens consistently with your vehicle, the onboard charger may need service
- DC fast charging may still work because it bypasses the onboard charger
Technical details
- Error code
- DiodeCheckFailed
- Category
- Vehicle
- Classification
- safety
- Source
- For current specifications, see U.S. Department of Energy AFDC. EVcourse is not affiliated with U.S. Department of Energy AFDC.
Related charging terms
Understanding these terms can help you troubleshoot this error:
Seeing this error at the charger?
Drivers can verify this specific error by scanning the screen with EVcourse. The app reads any charger display, any language. Free to try on iOS.
Other errors
From Finn, engineer: This error code is part of the ChargeX MREC standard used across public charging networks. Always follow the instructions on the charger display. If the error persists, contact the charging network's support line or try a different charger.
The EVcourse app provides instant troubleshooting and expert explanations at the charger. Scan any station or car screen for step-by-step help, free to start on iOS.
Don't understand the screen? Scan it.
Point your phone at any charger or car screen for instant help. Any brand, any language. Free to try on iOS.
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