BMW EV charger shows E05; unit powers up but refuses to charge any vehicle

Safety first: De-energize the circuit at the breaker before opening the Wallbox or touching terminals.

• Measure voltage under load: Have an electrician measure voltage at the Wallbox while another load is active on the same circuit (if any). Significant drop indicates undersized wiring or overloaded circuit.
• Inspect input wiring: With power off, check that all supply conductors are tight and correctly landed in the BMW Wallbox terminal block. Retighten to specified torque.
• Check cable size and length: Compare installed cable cross-section and run length with BMW installation guidelines. If undersized, the supply cable must be upgraded.
• Power-cycle and retest: After corrections, turn the breaker back on, wait for the Wallbox to boot, and reconnect the vehicle.

If E05 persists with correct supply voltage and wiring, the internal low-voltage power supply or sensing circuit is likely faulty. Replacement of the internal power supply module or main board should be performed by a BMW-authorized technician.