This app is the most complete offline OBD trouble code definitions. Especially for JDM cars. To use this app need OBD II Bluetooth Dongle. We recommend to use vgate icar pro bluetooth 4.0 device. This app only for home use. This app allows you to read diagnostic data from your vehicle. You can create virtual dashboards showing multiple vehicle sensors, estimate fuel economy, read diagnostic trouble codes, and turn off your check engine light