Some diagnostic implementations require an encrypted connection before routing is accepted. A plain connection being rejected is not necessarily a damaged gateway.

What to check next

Keep the exact message and check the approved tool’s support for that connection mode. Distinguish a certificate or connection requirement from an ECU fault code. Any software or account changes should follow the provider’s documented procedure.

Useful information for an enquiry

Send the tool and interface details, excluding passwords, access tokens and private certificate material.

Do not switch off verification to make the message disappear. Protected diagnostics must remain within the authorised access route.

Speak to AXION

For CAN-bus and vehicle-network diagnostics, send your vehicle details and fault report. Workshop assessment is in Didcot, Oxfordshire. Suitable postal or remote work is confirmed before booking.

Technical background from the project maintainers. The referenced design explains the principle; the vehicle-specific procedure determines the repair.