OBD2 Scanners Buying Guide Imagine that you are driving your car quietly, when all of a sudden, the most mysterious indicator of all lights on the dashboard and asks you to "check the engine." What is the meaning of such a message?
A car engine is a relatively huge and complex body and therefore the "engine check" admits of many possible answers. And it is here that a code reader of an on-board diagnostic system II (OBD-II) can be very useful because it allows you to specify the origin of the fault. Obtain an OBD-II diagnostic device. These devices are available for sale online or at suppliers of spare parts for cars.
If your smartphone is usable with Bluetooth, you can purchase an ODB reader that directly displays the codes and their meanings. If your car or van was built before 1996, you should install an OBD-I type diagnostic device that is more suitable for cars, but this device does not use the OBD-II coding system. It should be noted that this our website deals mainly with OBD systems. This system continuously monitors the vehicle's exhaust emissions, and whenever these emissions become 150% or more of the limit values laid down by the law, the failure is reported to the driver through an On the dashboard that displays a message prompting you to check the engine.
Via: https://www.wlap.org/best-obd2-scanner/