On-Board System Readiness Test Mode: Description

All OBD-II scan tools should be able to display On-Board System Readings (OSR) test. The OSR will display monitors on the vehicle and status of all monitors; complete or not complete. If not complete, the scan tool will display which monitor has not completed. Comprehensive component, fuel and misfire monitors run continuously and will always display YES. Only a PCM reset, or keep alive RAM reset will cause non-continuous monitors to reinitialize and display NO.