When you have any familiarity with On-Board-Diagnostics or OBD2 then you know it is a system that monitors your vehicle's performance and definately will let the driver know of any problems through the 'Check Engine' light about the dashboard. All car, light truck and SUV manufacturers happen to be mandated http://www.madisonbst.com/index.php?page=user&action=pub_profile&id=201733