A diagnostic request can target a specific controller or a group of controllers. The responses expected from those two situations are different.

How to narrow it down

Confirm how the tool addressed the request and which modules the vehicle is configured to contain. Compare the same operation under a supported vehicle profile before treating a missing group response as a dead ECU. Preserve the complete network scan for context.

What to include with the fault report

Send the request type, vehicle configuration and tool report.

Not every controller must answer every broadcast-style request. The requested service and vehicle implementation determine the expected behaviour.

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 CSS Electronics. The referenced design explains the principle; the vehicle-specific procedure determines the repair.