Vag Flash File Info -

| ECU Family | CPU | Typical Flash Size | |------------|-----|--------------------| | MED9.1 | Infineon Tricore | 1.5 MB | | MED17.5 | Tricore 1796 | 2 MB – 4 MB | | EDC16 | Tricore 1130 | 1 MB | | EDC17 | Tricore 1792 | 2 MB – 4 MB | | Simos 18 | Tricore 297 | 6 MB – 8 MB | | MG1CSxxx | Aurix TC3xx | 8 MB – 16 MB |

Always verify size before flashing. A 4 MB file written to a 2 MB ECU will overwrite critical boot areas.

This is what tuners modify. It includes fuel maps, ignition timing, boost pressure limits, torque limiters, and throttle response curves. The "info" here includes the checksum—a mathematical signature that ensures the data hasn't been corrupted. Vag Flash File Info

VAG frequently releases software updates to fix cold-start issues, emissions compliance, or sensor sensitivity. Using outdated Flash File Info means you miss critical patches. Conversely, flashing a newer file without verifying hardware revision can cause limp mode.

Many DIYers make the mistake of assuming "any file from an Audi A3 will work on my VW Golf." This is dangerous. Here is why precise info matters. | ECU Family | CPU | Typical Flash

VAG ECUs are notorious for multiple interdependent checksums. Flashing a modified file without recalculating all of them will trigger:

Most professional tools (ECU safe, KESS, MPPS) auto-correct checksums. But if you’re writing via boot mode (BDM or JTAG), you must recalculate manually. This is what tuners modify

Warning: Even changing a single byte in a map requires a full checksum update across all regions.

A: Reputable tuners will provide a "file info sheet" showing the original checksum, the modified checksum, and a note on which OBD protocols are preserved (UDS, KWP2000, etc.). If they refuse, walk away.

You buy a used ECU from a salvage yard. You have the physical part, but the Flash File Info is for a different transmission (manual vs. DSG).