Negative response code 0x26 means a failure condition is preventing the requested action. A routine may be blocked because another problem has not been resolved.

Interpreting the evidence

Read and preserve the complete fault memory before clearing anything. Identify which condition the approved procedure requires to be corrected, then repair and verify it. Repeating an adaptation while the blocking fault remains can waste time and obscure the original evidence.

Keep this evidence

Send the complete fault list, routine name and any prerequisite messages.

Clearing a code is not the same as correcting its cause. The operation should proceed only when its proper conditions are satisfied.

Speak to AXION

For module programming and coding support, 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 py-uds. The referenced design explains the principle; the vehicle-specific procedure determines the repair.

Related reading — UDS response 0x33 during authorised module programming. Browse all vehicle-electronics diagnostic notes or return to the repair library.