Charger shows E03 and will not energize; vehicle may show 'ground fault' or 'charging station error'; charging stops immediately after plug‑in.

Safety first: Turn OFF the charger breaker. Do not use the charger if you suspect water ingress or insulation damage.

• Check for moisture: Inspect the Type 2 connector, cable, and wallbox housing for signs of water, condensation, or corrosion. If the charger is installed outdoors, ensure the cable entry glands and cover gasket are intact.
• Dry the components: If moisture is present, disconnect the cable from the vehicle, wipe dry, and allow the connector and wallbox to air‑dry for at least 24 hours in a dry environment before retesting.
• Test with another vehicle (if possible): If E03 only occurs with one vehicle, the fault may be in the vehicle’s onboard charger. Try another EV to isolate the issue.
• Inspect internal RCD wiring (advanced): With power OFF and cover removed, locate the residual current sensor (toroid) and RCD module. Check that all conductors pass correctly through the sensor and that no wires are pinched or damaged.
• Reset and retest: Restore power at the breaker, then follow the Volvo charger manual to reset any internal RCD or fault memory (often by holding the front button or power‑cycling). Attempt a new charge session.

If E03 recurs with multiple vehicles and in dry conditions, the integrated RCD or DC leakage sensor is likely defective. Replacement of the RCD module or main control board should be performed by a licensed electrician or Volvo‑authorized installer.