GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Avalanche - 4WD 🢒 Engine 🢒 Engine Controls - 8.1L 🢒 Inspection/Maintenance Evaporative Emission System Set

Description

The purpose of this test is to satisfy the enable criteria necessary to execute I/M readiness diagnostics for the Evaporate Emission (EVAP) System. The test may be used to set the I/M System Status indicators to YES. The I/M System Status Display on the scan tool provides an indication of when the control module has completed the required tests. The I/M System Status does not indicate that the tests have passed or failed. When all of the diagnostics for a specific system have run and passed the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the other tests for that system have not run. Performing a visual inspection prior to running the EVAP test may prevent having to repeat the test. A failed or aborted test will require the vehicle to cool down in order to meet the enable criteria to run another test.

Conditions for Running
    • DTCs P0442, P0446, P0455, P0496 are not set.
    • The BARO is more than 75 kPa.
    • The fuel level is between ¼ and ¾.
    • The battery voltage is between 10-18 volts.
    • The engine coolant temperature (ECT) is between 3.75-30°C (39-86°F).
    • The intake air temperature (IAT) is between 3.75-30°C (39-86°F).
    • The difference between the ECT and the IAT is less than 8°C (14°F).

Diagnostic Aids

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load such as cooling fan or an A/C compressor clutch turning ON may cause the test to abort.

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. Important: Once the engine is started, DO NOT turn the engine OFF for the remainder of the procedure until the test is complete.

  3. Start the engine and idle.

    4. Caution: Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.

    Important: In order for this test to run, the vehicle must operate in the following conditions:

  4. Acceleration at part throttle to 72 km/h (45 mph) with this speed maintained until the engine reaches operating temperature. This may be up to 8-10 minutes depending on the start up coolant temperature.
  5. Continue the operating conditions for an additional 3 minutes after the engine reaches operating temperature.
  6. Decelerate to 0 km/h (0 mph).
  7. Idle the engine for 2 minutes.
  8. Turn OFF the ignition for 1 hour.
  9. After 1 hour, turn ON the ignition.
  10. Observer the EVAP System Status with a scan tool.

Did the EVAP 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

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 complete this test.
  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 the procedure until the scan tool indicates the diagnostic test has run.
  7. Repeat steps 4-6 for any additional required DTCs that have not run.
  8. Observe the I/M System Status display with a scan tool.

Did the EVAP 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

System OK