Choosing the correct reading method is fundamental to a successful file service submission. This guide provides a practical decision framework for professional tuners.
Start with OBD if: the ECU supports full OBD reading, the vehicle's OBD port is functional, and the tool supports the specific ECU variant. OBD is fastest, lowest-risk, and most convenient.
Use Bench if: OBD is not supported for the ECU variant, the DME has updated security that blocks OBD, or you need a more complete read (some ECUs provide fuller data via bench). Bench requires ECU removal and a proper bench setup with stable power supply.
Use Boot if: bench reading is not supported, the ECU requires boot mode for full access, or recovery is needed from a failed write. Boot mode involves connecting to specific test points on the ECU PCB and carries the highest risk.