Wallbox shows E07; charging does not start; vehicle may show ‘PE error’ or ‘Check grounding’.

Safety warning: A PE fault is a serious safety issue. Do not use the charger until the earth connection is verified and restored.

• Visual inspection: With power off, open the wallbox and locate the PE terminal (usually green/yellow). Ensure the conductor is firmly clamped and not corroded or broken.
• Check supply cable: Inspect the incoming cable for damage, especially at bends and entry points. Look for cuts or crushing that could affect the earth conductor.
• Continuity test (electrician): A qualified electrician should perform an earth continuity and loop impedance test from the wallbox PE terminal back to the main earth bar.
• Correct any loose or missing earth: Tighten or re-terminate the PE conductor as needed, following torque specifications.
• Control board fault: If the earth connection tests good but E07 persists, the earth monitoring circuit on the Mercedes-Benz wallbox control board may be defective and require replacement.