Description
The purpose of this test is to satisfy the enable criteria necessary to execute I/M readiness diagnostics for the secondary air injection (AIR) system. The test may be used to set the I/M System Status to YES. Ensure the vehicle meets the requirements listed in Conditions for Running before performing this test. Failure to meet the necessary requirements may produce inaccurate test results.
Conditions for Running
| • | The engine coolant temperature (ECT) is between 19-105°C (66-221°F). |
| • | The intake air temperature (IAT) is between 5-40°C (41-104°F). |
| • | The engine is idling. |
| • | The vehicle speed is 0 km/h (0 mph). |
Diagnostic Aids
The AIR pump generally operates once per ignition cycle, usually upon initial start up before the engine goes into Closed Loop fuel control. The diagnostic test is performed when the fuel system is in Closed Loop and the engine is idling.
If the diagnostic test does not run, observe the fuel trim correction. If the fuel trim correction is more than plus or minus 4 percent, the AIR System Test may not run. If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES.
The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. 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 required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the malfunction indicator lamp (MIL) is requested. The I/M System Status also registers the number of diagnostic trouble codes (DTCs).
The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down.
The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass.
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 a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort.
If a diagnostic test is difficult to run, maintain necessary enable conditions until the system status updates to YES.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Make sure you perform the I/M System Check before performing this test. Failure to do so may result in difficulty updating the status to YES.
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This step is to determine whether or not the AIR Service Bay Test has passed. If the system is operating correctly, the scan tool will not display any DTCs for the system and the I/M System status updates to YES. If the AIR Service Bay Test aborts because of lost enable conditions, the test can be repeated once the enable criteria is met.
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An AIR system DTC that fails during the Service Bay Test will appear on the scan tool in the DTC Information.
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The AIR Tests will begin during the specified idle period, shortly after the engine goes into Closed Loop fuel control .
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This step is to identify a first failure of a type B DTC. A DTC only appears on the I/M System Status display when it becomes a MIL illuminating DTC. This occurs on the second failure of a type B DTC. A first failure of a type B DTC will not allow the I/M System Status to update to YES. Refer to Diagnostic Aids.
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This step is to help identify any unique or unusual criteria required to run the diagnostic test in the event the universal set procedure does not. This information is located in the service information under Conditions for Running the DTC.
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The I/M System Status only reports on whether or not a diagnostic has run, not what the outcome of the test was. If any Emission Related DTC sets after the tests are complete, the DTC will require diagnosis.
Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
Did you perform the Inspection/Maintenance (I/M) System Check? | Go to Step 2 | ||||||
2 |
Is the vehicle equipped with an AIR Service Bay Test? | Go to Step 3 | Go to Step 5 | ||||
Did the AIR system pass the Service Bay Test? | Go to Step 8 | Go to Step 4 | |||||
Is the repair complete? | Go to Inspection/Maintenance (I/M) Complete System Set Procedure | -- | |||||
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 the Active Test to run, the vehicle must operate in the
following conditions:
Did the AIR System Status update to YES? | Go to Step 8 | Go to Step 6 | |||||
With a scan tool, observe the DTC Information. Does the scan tool indicate any failed DTCs? | Go to Step 7 | ||||||
Did the AIR System Status update to YES? | Go to Step 8 | Go to Diagnostic Aids | |||||
With a scan tool, observe the Emission Related DTC portion of the I/M System Status display. Does the scan tool indicate any Emission Related DTCs set? | System OK |
