An older scanner connects to some systems but cannot reach the controller you need. Before declaring that module dead, establish whether the diagnostic setup supports the vehicle and the requested function.
Protocol support is one part of compatibility
Bosch describes DoIP as an Ethernet-based diagnostic interface in its diagnostic product information. Its newer interface documentation lists DoIP and CAN FD support separately. Read Bosch’s diagnostic background and current interface specifications.
The practical point is to check the complete setup: vehicle coverage, interface, software and the operation being requested. A protocol logo alone does not establish that every coding or programming function is available on every vehicle.
Make the connection failure reproducible
For a referral, record the diagnostic tool and software version, the connection route and the exact error message. State whether other modules can be reached, whether identification succeeds, and whether the failure occurs only when a particular function is selected.
Include the low-voltage supply findings and any recent gateway, ECU or software work. Keep a full scan from a supported tool where available. Avoid changing several connection or software variables at once without recording what changed.
Diagnosis and programming are different bookings
Reading a controller’s identity does not mean a programming session is ready to start. The intended update, authorisation requirements and supported procedure need confirming separately. See our J2534 programming preparation guide for the information to preserve before an update enquiry.
Send AXION your communication report. UK garages can discuss complex diagnostic referrals without first removing a module on the assumption that a connection failure proves internal damage.
Reviewed September 2026. Use the complete manufacturer-specific fault description and vehicle repair information.