The device works with OBD II compliant vehicles (year 96 or newer in the US). It does NOT work with OBD I vehicles. For OBD II compliant vehicles, there should be a 16 pin DLC (Diagnostic Link Connector) usually under the dash or behind ashtray AND a note on a sticker or nameplate under the hood: “OBD II compliant/certified”.

It reads check engine light trouble codes (sometimes called service engine soon).

No, it does not read or reset these. Only supports check engine light.

Check the cigar fuse of your vehicle and try on another vehicle to see if the OBD connector is in good condition.

Make sure your vehicle is OBD2 compliant, the device is plugged in well and the ignition is at ON. Also start the vehicle to try again. Try it on another vehicle to see if the device is defective or incompatible with your vehicle.

First check if you have any other dash lights on. Sometimes fault from other systems will also cause the check engine light on. Or it’s a manufacturer-specific code that is not in the code library of the device.

Please note that not all codes can be cleared in this way. For some codes (especially confirmed or permanent), if the problem causing the code hasn’t been fixed, it won’t be cleared or it may be cleared, but will come back again right away. We usually suggest that you first use the code to check your car and fix the problems.

Not all vehicles support all the OBD II modes (depends on the car manufacturer).