Questions, answered

Into the 16-pin diagnostic socket under the dashboard, usually on the driver's side near the steering column. Sometimes it's behind a small cover. Push the adapter in all the way.

Unplug it when you're done. Most cars keep power on the diagnostic socket even with the car off, so an adapter left in slowly drains the battery, and a car parked for a while may not start. It's fine plugged in while you drive, for live data.

Yes. The app talks to your car through an adapter plugged into its diagnostic socket. We recommend the Athena OBD adapter: it's the one we test and support. Other Bluetooth LE ELM327 adapters may work, but many cheap copies answer wrongly or not at all, so we can't promise them. The demo car in the app needs no adapter.

Make sure the adapter is pushed all the way into the socket and the ignition is on (the dashboard lights on). Turn Bluetooth on, and allow Athena OBD to use it when your phone asks. Don't pair the adapter in your phone's Bluetooth settings: the app connects by itself.

In the app, open Settings and tap Send the log. Add a message and your email address if you'd like an answer. The app sends us its log of what it tried with your car and shows you a reference, like L-7K2QXM. Or email support@athenaobd.app and quote that reference. Nothing is sent unless you tap Send. What the log contains.

Every car and light truck sold in the US from 1996 on has the socket. From 2008 they all speak the language our adapter reads. Before that, many Fords, GMs and Chryslers used an older one (J1850) it doesn't, so those may not connect. Other cars from 1996 on work, including hybrids. Check yours by VIN or year.

Checking that your car and adapter work together, and reading the car's stored codes, with what each means and a guide to how urgent it usually is, are free. Saved reports and the demo car are free too. One in-app purchase unlocks the rest for good: the emissions test check, live data on dashboards you arrange, recording a drive and playing it back, trip and fuel economy, 0-60 and quarter-mile timers, pending and permanent codes, what the engine was doing when a code was stored, the car's self-test results, and resetting codes after a repair. No subscription. See the comparison.

Athena OBD reads what every car shares through the standard diagnostic socket: the engine and emissions systems, which are what turn on the check engine light and what the emissions test looks at. Warning lights for the airbags, ABS brakes, the body electronics and the like come from modules each carmaker talks to in its own way, so a generic reader like Athena OBD can't see those codes.

No, it usually does the opposite. Clearing codes also resets the car's self-tests, and the station will ask you to come back until they've finished (a few days of normal driving). Fix the fault, clear the codes, then drive normally for a few days, in town and on the highway (the car's "drive cycle"), and use Athena OBD's emissions test check to see when you're ready.

It tells you which system reported a problem, what the code means and a general guide to how urgent that kind of fault usually is. The guide comes from the code's type, not from looking at your car, so treat it as a starting point: if the car drives, sounds or smells wrong, or the light is flashing, stop and have it checked. A code points at a fault, not always a part: a mechanic's diagnosis is what a repair needs.

Athena OBD reads your BMW's engine and emissions like any car's. For the whole car (airbags, ABS, the instrument cluster, body modules) and service resets, our sister app AutoLingo for BMW is made for it, with its own adapter.

If the adapter doesn't work with your car, send it back within 30 days of delivery for a full refund. Email support@athenaobd.app with your order number and we'll send the return details.

The adapter has a one-year warranty against defects.

Not yet. The adapter ships to US addresses, and the app is in the US App Store and Google Play only, for now.