Charger shows E04 and will not charge; app may show 'Ground not detected' or 'Improper grounding'.

Critical safety warning: Do not use the charger until the ground fault is corrected. An open ground can create a shock hazard. Turn off the breaker before any inspection.

• Verify supply wiring (electrician recommended): Remove power at the main panel. A qualified person should remove the Emporia charger cover and confirm that the ground conductor is securely landed on the ground terminal and that all lugs are tight.
• Inspect the branch circuit: At the service panel, check that the ground wire is properly connected to the ground bar and that there is no corrosion or loose screws.
• Test outlet (if plug-in model): Use a receptacle tester or multimeter to verify correct hot/neutral/ground configuration. Replace any faulty receptacle.
• Power cycle and retest: After tightening and verifying all ground connections, restore power and see if E04 clears.
• If wiring is confirmed good: The internal ground detection circuit on the control board may be defective. In that case, the control board assembly should be replaced by a qualified technician.