Test Description
WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic procedures.
- 1 - 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.
- 2 - This step is to run the HO2S Heater Tests and initiate the EVAP System Test. Preprogramming the scan tool will reduce the amount of time the O2S heaters operate while verifying the enable criteria. The engine control module considers the engine to be cold if the ECT is less than 86°F (30°C) and ECT and IAT are within 14°F (8°C) of each other at start-up.
- 3 - This step is to run the EVAP, secondary air injection (AIR) and the oxygen sensor tests. The EVAP Test begins once the engine coolant reaches a calibrated temperature. The AIR Test, if equipped, begins shortly after Closed Loop and the indicated speed is achieved. The oxygen sensor tests begin once the engine is at operating temperature, in Closed Loop fuel control, and a calibrated amount of time has elapsed.
- 4 - This step is to run the Exhaust Gas Recirculation (EGR) tests. The EGR tests are run during a gradual deceleration with a closed throttle. The vehicle speed is required in order to maintain a high, steady Manifold Absolute Pressure (MAP) signal.
- 5 - 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.
- 6 - Perform the individual system test for any of the systems that do not update to YES.
- 7 - 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.