There has been a rapid growth of electronics used inside automobiles today from electronic fuel injection, automatic gear box, anti-lock braking system to telematics and in car infotainment systems which has also led to the development of various automotive diagnostic protocols to ensure good vehicle performance. The diagnostic tester is usually used as External Test Equipment by the service technician to request diagnostic functions to be performed in one or more servers/ECU. The server uses the application layer defined by the diagnostic services to respond back to the client/tester. However, using the diagnostic tool on-board would not only help in preventing the catastrophic failures but also letting the driver know of the malfunctioning of any of the vehicle modules which might be serviced suitably later. Here we introduce a diagnostic system which regularly monitors all the car modules and also takes care of the dysfunctional units through the various services defined in the Unified Diagnostic Services Standard.