Guide

Finding and using your OBD-II port

Where the port is, what hardware plugs into it, and what a read session looks like.

Identifying your ECU (Bosch MED17.3.x and friends)

Match your car to its ECU family using labels, part numbers, and the intake form.

Reading your ECU: tools and methods (OBD vs bench)

Getting a complete, correct .bin out of your car before you upload it.

Preparing your file and uploading it to Flow VIN Tune

File formats, full vs partial reads, and walking the upload flow without surprises.

Stage 1 vs Stage 1+ — what actually changes

What each service modifies, and how to pick the right one for your car.

Writing your approved tune (and reverting to stock)

Flashing the delivered file back to the car, plus how revert-to-stock works.

Why files get rejected — and how to fix yours

The common rejection causes (partial read, wrong file, unsupported ECU) and the fix for each.