Overview/On Board Diagnostics

OBD II Function: Overview (On Board Diagnosis)


Since the 1996 model year all vehicles must meet OBD II requirements. OBD II requires the monitoring of virtually every component that can affect the emission performance of a vehicle plus store the associated fault code and condition in memory. If a problem is detected, the OBD II system must also illuminated a warning lamp (Malfunction Indicator Light - MIL "Check Engine Light"" located on the vehicle instrument panel to alert the driver that a malfunction has occurred. In order to accomplish this task, BMW utilizes the Engine Control Module (ECM/DME) as well as the Automatic Transmission Control Module (EGS/AGS) and the Electronic Throttle Control Module (EML) to monitor and store faults associated with all components/systems that can influence exhaust and evaporative emissions.