Description
The purpose of this test is to satisfy the enable criteria necessary to execute inspection maintenance (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. The I/M System Status Display on the scan tool provides an indication of whether 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.
Conditions for Running
| • | The engine coolant temperature (ECT) is between -10 to +110°C (14-230°F). |
| • | The intake air temperature (IAT) is between -10 to +100°C (14-212°F). |
| • | The battery voltage is more than 11.7 volts. |
| • | The start-up ECT is less than 70°C (158°F). |
| • | The engine is running for more than 30 seconds. |
| • | The mass air flow (MAF) is less than 22 g/s. |
| • | The air fuel ratio is 14.7:1. |
| • | The engine load is less than 40 percent. |
| • | The vehicle speed is more than 25 km/h (15 mph). |
| • | The engine is operating in Closed Loop for more than 15 seconds. |
| • | The engine speed is more than 850 RPM. |
| • | The fuel system is operating in fuel trim cells 1, 2, 4, or 5. |
| • | The short term FT is between -4 and +4 percent. |
| • | The engine is not operating in any of the following modes: |
| • | Power Enrichment mode |
| • | Decel Fuel Cut-off mode |
| • | Catalyst Over Temperature mode |
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. Some systems will perform a Passive Diagnostic Test at this time. The Active Diagnostic Test is performed after the engine goes into Closed Loop Fuel Control. On vehicles that perform a Passive Test, the Active Test will only run if the Passive Test fails or is indeterminate. The Active Test may not run if the Passive Test passes.
If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES.
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.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Inspection/Maintenance (I/M) System Check? | Go to Step 2 | |
2 |
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 5 | Go to Step 3 |
3 | Observe the DTC Information with a scan tool. Does the scan tool indicate any failed DTCs? | Go to Step 4 | |
4 |
Did the AIR 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? | System OK |
