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Home >> Jeep >> 2004 >> Grand Cherokee Overland, AWD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Powertrain Diagnostic Procedures >> System Description And Functional Operation >> Function Operation >> On-Board Diagnostics >> OBDII/EUROIII Monitor Run Process, JTEC >> Monitor Preliminary Checks:
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Monitor Preliminary Checks:

  1. Plug a DRB III into the vehicle's DLC.
  2. Turn the ignition, KEY ON - ENGINE OFF. Watch for MIL lamp illumination during the bulb check. MIL lamp must have illuminated, if not, repair MIL lamp.
  3. On the DRB III Select #1 DRB III Stand alone
  4. Select #1 1998-2002 Diagnostics.
  5. Select #1 Engine.
  6. Select #2 DTCs and Related Functions.
  7. Select #1 Read DTCs
    • * Verify that No Emissions Related DTCs are present.
    • * If an Emissions DTC is Present, the OBD II Monitors may not run and the CARB Readiness will not update.
    • * The Emissions related DTC, will need to be repaired, then cleared. By clearing DTCs, the OBD Monitors will need to be run and completed to set the CARB Readiness Status.
  8. Return to Engine Select Function Menu and Select #9, OBD II Monitors.
  9. Select #3 CARB Readiness Status.

    Do all the CARB Readiness Status Locations read YES?

    • *YES, then all monitors have been completed and this vehicle is ready to be I/M or Emission Tested.
    • *NO, then the following procedure needs to be followed to run/complete all available monitors.
NOTE:
  1. Only the monitors, which are not  YES in the CARB Readiness Status, need to be completed.
  2. Specific criteria need to be met for each monitor. Each monitor has a Pre-Test screen to assist in running the monitor. For additional information, refer to the Chrysler Corporation Technical Training Workbook.

The most efficient order to run the monitors has been outlined below, including suggestions to aid in process. The first two monitors have very similar enable criteria; it is possible that the Evaporative Leak Detection Monitor will run during the O2 Sensor Heater Monitor.

  1. O2 Sensor Heater Monitor  This monitor requires a cold start, usually an overnight soak or parked for at least 8 hours without the engine running. The engine coolant temperature must be within 10 degrees of ambient/battery temperature, and the sensed Ambient (outside) Temperature must be between approximately 0°F and 100°F. For the monitor run conditions, select the O2S HEATER MON PRE-TEST in the DRB III, OBD II Monitors Menu.
  2. Evaporative Leak Detection Monitor (If the vehicle is equipped with an LDP system)  This monitor requires a cold start, usually an overnight soak or parked for at least 8 hours without the engine running. The engine coolant temperature must be within 10 degrees of ambient/battery temperature, and the sensed Ambient (outside) Temperature must be between approximately 40°F and 90°F. For the monitor run conditions select the EVAP LDP MON PRE-TEST in the DRB III, OBD II Monitors Menu.
  3. Catalyst Monitor  The vehicle will need to be driven at highway speed for a few minutes. If the vehicle is equipped with a manual transmission, using 4th gear may assist in meeting the monitor running criteria. For the monitor run conditions, select the EWMA CAT MON PRE-TEST in the DRB III, OBD II Monitors Menu.
  4. O2 Sensor Monitor  The vehicle will need to be driven for a period of time and brought to a stop for a short period of time with the Automatic Transmission left in Drive. The O2S Monitor will not run in Park or Neutral on an Automatic Transmission equipped vehicle. For the monitor run conditions, select the O2S MON PRE-TEST in the DRB III, OBD II Monitors Menu.
  5. Purge Monitor  All the Purge Free (PF) cells must update on the ADAPTIVE MEMORY screen before the Purge Flow Monitor will run. For the monitor run conditions, select the PURGE FLOW MON PRE-TEST in the DRB III, OBD II Monitors Menu. The Purge Flow Monitor will not run in Park or Neutral on an Automatic Transmission equipped vehicle. The purge flow monitor will attempt to run every other  throttle closure. If all of the parameters are met and it still does not run, with your foot firmly on the Service Brake, slightly (1/4) open the Throttle and quickly close the Throttle. This will allow the purge Free update to happen, and then the Purge Flow Monitor will Run.
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