In00Z–01 – Introduction General Information In–13 OBD Monitor Drive Patterns Purpose of the Readiness Tests The On–Board Diagnostic (OBD II) system is designed to monitor the performance of emission–related com- ponents and report any detected abnormalities in the form of Diagnostic Trouble Codes (DTCs). Since the various components need to be monitored during different driving conditions, the OBD II system is designed to run separate monitoring programs called Readiness Monitors. Many state emissions inspection and main- tenance (I/M) programs require that vehicles complete their Readiness Monitors prior to beginning an emis- sions test. NOTE:
A diagnostic trouble code for a subsystem or component within a subsystem will not set until the associated readiness monitor is complete. The readiness monitor status will be reset to incomplete if: The battery is disconnected. DTCs have been cleared. The monitor drive cycle has not been completed. The monitor status can be checked using an OBD II scan tool. When using hand–held tester, monitor status can be found in the Enhanced OBD II Extended Data List or under CARB OBD II. In the event that any moni- tors show incomplete, follow the appropriate Readiness Monitor Drive Pattern to change the readiness sta- tus to “complete”. CAUTION:
Strict observance of posted speed limits, traffic laws, and road conditions are required when per- forming these drive patterns. NOTE: These drive patterns represent the fastest method to satisfy all necessary conditions which allow the specific readiness monitor to complete. In the event that the drive pattern must be interrupted (possibly due to traffic conditions or other fac- tors) the drive pattern can be resumed and, in most cases, the readiness monitor will still set to com- plete. To ensure rapid completion of readiness monitors, avoid sudden changes in vehicle load and speed (driving up and down hills and/or sudden acceleration). 1996–2003 ADDITION OF OBD (OTH021U) 13 Author :
Date: Pattern No. Readiness Code Patterns Page 1 EGR Monitor (Except 1FZ–FE engine) In–27 2 EGR Monitor (For 1FZ–FE engine) In–28 3 Catalyst Monitor (Front and rear heated oxygen sensors equipped) In–29 4 Catalyst Monitor (A/F sensor equipped) In–30 5 EVAP Monitor (Fuel tank pressure monitor) In–31 6 EVAP Monitor (Vacuum monitor and LEV II) In–33 7 EVAP Monitor (Engine RPM monitor) In–35 8 Heated Oxygen Sensor Monitor (Front and rear heated oxygen sensors equipped) In–36 9 A/F Sensor and Heated Oxygen Sensor Monitor (Front A/F sensor and rear heated oxygen sensor equipped) In–37 10 Oxygen Sensor Heater and A/F Sensor Heater Monitor In–38