A system and method of diagnosing a vehicle using a smart phone to collect symptomatic data from the user/driver. The symptomatic data is received by the user in response to symptomatic questions displayed on the user's smart phone. The symptomatic questions are generated in response to deriving vehicle characteristic information (i.e., year, make, model, engine) from vehicle identification information (i.e., the vehicle identification number (VIN) or license plate information). In this regard, vehicle-specific symptomatic questions may be presented to the user so as to ask pertinent questions based on a history of diagnoses of vehicles sharing similar vehicle characteristics.