ScanBuddy is an OBD2 scanner app that reads what your vehicle has already recorded and shows it in plain language. Know what the check engine light means before you go to the shop, and see whether the readiness monitors are ready before an inspection.

WHAT IT SHOWS

• Check engine light — whether it is on
• Trouble codes — stored, pending and permanent, with descriptions when available
• Readiness monitors — which self-tests are finished and which are still waiting
• Live sensor data — speed, RPM, coolant temperature, fuel trim and more

CODES, EXPLAINED

Tap a code and ScanBuddy writes the question for you and opens it in a web search: what the code means on your year, make and model, the likely causes, and what a shop would check. The question is asked in your language, and if you set your state, it covers that state's inspection rules. Your VIN is never sent.

READINESS MONITORS, EXPLAINED

If your vehicle needs an emissions inspection, the readiness monitors matter along with the light. ScanBuddy counts only the monitors your vehicle reports as supported, so a vehicle without a secondary air system is never shown waiting for that test.

WHEN A VEHICLE ONLY ANSWERS PART OF IT

Some vehicles reply to part of what they were asked and stay quiet on the rest. ScanBuddy marks the scan Partial Data and shows which parts did not answer, instead of filling the gap with a zero. You are never told a vehicle has no trouble codes when the truth is that it never replied.

FREE, NO ACCOUNT

No sign-up, no subscription, nothing locked behind a payment. Your scans are saved on your phone.

WHAT YOU NEED

A Bluetooth Classic OBD2 adapter, paired in your phone's Bluetooth settings before you scan. Bluetooth Low Energy adapters, often sold as "for iPhone", cannot connect. Neither can Wi-Fi adapters.

IT ONLY READS

A scan changes nothing in your vehicle. Clearing trouble codes is a separate action, never automatic, and it always asks first. Clearing may also reset the readiness monitors.

WHAT IT IS NOT

ScanBuddy is a scan tool, not a mechanic. It shows you what your vehicle reports. It does not find or repair the cause of a fault, and it cannot tell you whether a vehicle is safe to drive.

English and Spanish throughout. Built by one person — if something does not work, there is a Report a problem button in the app.