Audi EV charger shows E08 and will not start charging; often associated with installation on a three-phase supply.

Safety first: Three-phase work must be performed by a qualified electrician. Turn off the main supply before opening any covers.

• Verify supply phases: An electrician should measure voltage between L1-L2, L2-L3, and L3-L1 at the wallbox terminals. All should show correct line-to-line voltage. If one phase is missing, trace back to the distribution board and correct the wiring or breaker.
• Check phase order: Some Audi chargers require a specific phase sequence. Use a phase rotation tester to confirm correct order. If incorrect, swap two phases at the supply (with power off) to correct rotation.
• Inspect terminal block: With power off, check that all phase conductors are firmly clamped in the internal terminal block and show no signs of overheating.
• Board-level diagnostics: If supply is correct but E08 persists, the phase monitoring circuit on the main control board may be defective. Replace the main control board following Audi service procedures.

Do not operate the charger with a missing phase. Correct wiring issues or replace faulty monitoring electronics.