Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 1:  Before you perform this test, you must perform the I/M System Check. Failure to do so may result in difficulty updating the status to YES.
2. 2:  This step is to run the HO2S heater tests and initiates the EVAP system test. Preprogramming the scan tool will reduce the amount of time that the oxygen sensor heaters operate while verifying the enable criteria. The engine control module considers the engine to be cold if the following conditions are met:
   • The ECT is less than 30° C (86° F).
   • The ECT and the IAT are within 8° C (14° F) of each other during start-up.
3. 3:  This step is to run the evaporative emission (EVAP) test, the secondary air injection (AIR) test, and the Oxygen Sensor Test. The EVAP Test begins when the engine coolant reaches a calibrated temperature. If the vehicle is equipped with this equipment, the AIR Test begins after Closed Loop, and after the indicated speed is achieved. The oxygen sensor tests begin when the engine reaches the operating temperature, in Closed Loop Fuel Control, and when a calibrated amount of time has elapsed.
4. 4:  This step is to run the Catalyst Tests. This test runs during the idle period immediately following a cruise period that meets a minimum calibrated RPM and time period.
5. 5:  Perform the individual system test for any of the systems that do not update to YES.
6. 6:  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 emissions-related DTC sets after the tests are complete, the DTC will require diagnosis.