Poor Vehicle Maintenance

The sensitivity of OBD-II diagnostics will cause the check engine lamp to turn on if the vehicle is not maintained properly. Restricted oil filters, fuel filters, and crankcase deposits due to lack of oil changes or improper oil viscosity can trigger actual vehicle faults that were not previously monitored prior to OBD-II. Poor vehicle maintenance can not be classified as a non-vehicle fault, but with the sensitivity of OBD-II diagnostics, vehicle maintenance schedules must be more closely followed.