A serial device’s bus address and its internal memory address are different things. Confusing them can produce reads from the wrong location or make a present device appear missing.
What to check next
Confirm the memory family, capacity and address arrangement from its documentation. Check the tool’s selected profile and adapter before treating the result as corrupted data. Preserve the complete read, including its size and method, so it can be compared consistently.
Useful information for an enquiry
Provide a clear chip marking and the programmer profile used.
A response somewhere on the bus does not establish that the correct memory has been read. Other connected devices can also respond.
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 Microchip. The referenced design explains the principle; the vehicle-specific procedure determines the repair.
Related reading — SPI memory reads that change with the communication settings. Browse all vehicle-electronics diagnostic notes or return to the repair library.