OBD2 Scan: Check Engine Light

Check engine light on? Plug in an ELM327 OBD2 adapter and this OBD2 scanner reads your car's trouble codes in seconds, tells you what each code means, how serious it is and whether it is OK to keep driving. A car code reader, OBD2 code reader and car diagnostic tool in one app, for OBD2 Bluetooth, Bluetooth LE and Wi-Fi adapters.

WHAT YOU GET
• Read check engine codes: stored, pending and permanent diagnostic trouble codes (DTC)
• Clear codes and turn off the check engine light after a repair (Pro)
• Engine code reader with plain explanations for more than 9,000 standard car codes and fault codes (P, B, C and U codes)
• Severity and "Can I keep driving?" for the most common codes (Pro)
• Fix guides with likely causes and what to check, for the 140+ most common codes (Pro)
• Live data: engine speed (RPM), coolant temperature, fuel trims, oxygen sensors, intake air, throttle and more, with live charts
• Freeze frame: the engine conditions the car saved when the code was set
• Emissions readiness: see if your car is ready for a smog check or emissions inspection
• Vehicle info: VIN, calibration ID, control module name, protocol and battery voltage
• Dashboard with large gauges for speed, RPM, coolant temperature and battery
• Metric or imperial units (km/h or mph, °C or °F)

HOW IT WORKS
1. Plug an ELM327 OBD2 adapter into the diagnostic port under the dashboard.
2. Turn the ignition on.
3. Connect over Bluetooth, Bluetooth LE or Wi-Fi and tap Run diagnostic scan.
No adapter yet? Try the built-in demo car to see how the car scanner works.

WHICH CARS WORK
Most gasoline cars and light trucks sold in the USA since 1996 use OBD-II (also written OBD II or OBD 2). Most European cars use EOBD (gasoline from 2001, diesel from 2004). The app talks to the car through an ELM327-compatible adapter; not every vehicle, adapter or value is supported. Manufacturer-specific codes are shown with their system and group but without a full description.

COMMON CHECK ENGINE CODES IT EXPLAINS
P0300 random misfire, P0171 system too lean, P0420 catalytic converter efficiency, P0442 EVAP leak, P0455 large EVAP leak, P0128 coolant thermostat, P0133 oxygen sensor slow response, P0401 EGR flow, P0505 idle control and thousands more.

PRO
Pro unlocks clearing codes, severity and "Can I keep driving?", the fix guides, more live data values on screen at the same time (the free version shows 1, or 2 after watching a short ad), sharing scan reports with your mechanic, and removes ads. Reading codes, code descriptions, freeze frame, emissions readiness, vehicle info and the dashboard do not need Pro. Weekly (with a free trial), monthly and lifetime options are available in the app; subscriptions renew automatically until you cancel in Google Play.

IMPORTANT
This OBD2 app gives general information, not a replacement for a professional mechanic. Do not use the app while driving. Clearing codes does not fix the fault, and it resets the emissions readiness tests.

ELM327 is a product name of Elm Electronics. This app is not affiliated with any adapter or car manufacturer.

Recent changes:
New look: every screen redesigned with real photos, new fonts and clearer cards. Weekly plan now shows the 3-day free trial up front. Minor fixes.