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Home >> Hummer >> 2006 >> H3 Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 3.5L - Trouble Shooting >> Inspection/Maintenance (I/M) Catalyst System Set Procedure >> Diagnostic Aids
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Diagnostic Aids

The control module runs a maximum of 12 tests per trip. If there is an impending failure, the system may require more time than was allotted in the system set procedure. If any DTCs do not run and no DTC is set, review the appropriate scan tool data list and service information. This will give an indication of why the DTCs do not run. Some may abort due to changes in the conditions while running. For example, changes in engine load such as a cooling fan or A/C compressor clutch turning ON, may cause a DTC to abort. If the Catalyst I/M System Status does not update to YES, the procedure can be repeated until a YES status is achieved.

Inspection/Maintenance (I/M) Catalyst System Set Procedure

Step Action Yes No
1 Did you perform the Inspection/Maintenance (I/M) System Check? Go to Step 2  Go to Inspection/Maintenance (I/M) System Check 
2
  1. Ensure the vehicle is within the Conditions for Running specified in the supporting text.
  2. Turn OFF all of the accessories, e.g., A/C, blower fan, etc.
  3. Start and allow the engine to idle for 2 minutes.
    4. CAUTION: Refer to Road Test Caution in Cautions and Notices.
  4. Accelerate at part throttle to 89 km/h (55 mph) with this speed maintained until the engine reaches operating temperature. This may take up to 10 minutes.
  5. Continue operating under these conditions for an additional 8 minutes after the engine reaches operating temperature.
  6. Decelerate to 0 km/h (0 mph).
  7. Allow the engine to idle for 1 minute while the following criteria is maintained:
    • Service brake depressed
    • Automatic transmission in DRIVE or manual transmission in NEUTRAL with the clutch pedal depressed
  8. Observe the I/M System Status display with a scan tool.
Did the Catalyst System Status update to YES?		 Go to Step 5  Go to Step 3 
3 Observe the DTC Information with a scan tool.
Does the scan tool indicate any failed DTCs?		 Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information Go to Step 4 
4
  1. Refer to Inspection/Maintenance (I/M) System DTC Table  to determine which DTCs are required to run in order to update the Catalyst I/M System Status to YES.
  2. Observe the Not Ran Since Code Cleared display with a scan tool.
  3. Determine which of the DTCs required for a YES status has not run.
  4. Enter the DTC number in the Specific DTC menu of the scan tool.
  5. Operate the vehicle within the Conditions for Running the DTC, located in the supporting text for the diagnostic table of the DTC.
  6. Repeat numbers 4 and 5 of this step for any additional required DTCs that have not run.
  7. Observe the I/M System Status display with a scan tool.
Did the Catalyst System Status update to YES?		 Go to Step 5  Go to Diagnostic Aids
5 Observe the Emission Related DTC portion of the I/M System Status display with a scan tool.
Does the scan tool indicate any Emission Related DTCs set?		 Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information System OK
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