Guides
Plain answers about ECU numbers, ECU files and checking a car’s engine software.
ECU files
- ECU part numbers: where to find them and what they meanThe hardware number, the software number and the carmaker’s number: where each one is and which one you need.
- Bosch ECU numbers explained: 0 281, 0 261 and 1037Read a Bosch number at a glance, and see which numbers each Bosch family keeps in its file.
- What ECU is in my car? Four ways to find outA dealer with your VIN, the label, a diagnostic tool, or a read of the ECU.
- How to check your ECU software versionFrom the car over OBD, with a brand’s tool, or from a read of the ECU.
- How to open an ECU .bin file without tuning softwareFour free ways to look inside a read, and what none of them can show you.
- Free WinOLS alternatives for looking at an ECU fileWhat each free tool shows, what it needs, and which one to pick.
- How to compare two ECU filesSee which tables changed between an original and a modified read, and how to read the result.
Cars
- How to tell if a car has been tuned or remappedFive ways to find out, from asking the seller to a full read at a tuning shop, and what each one misses.
- What is a CVN? The calibration verification numberThe two codes that identify a car’s engine software, who requires them and what a mismatch means.
- Smog check failed for Cal ID or CVNWhy California fails cars whose software doesn’t match a valid configuration, and how owners get it to pass.