Conditions for Running the DTC

WARNING: This page is about a different car, the 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0128, P0222, P0223, P0443, P0449, P0452, P0453, P0455, P0496, P0502, P0562, P0563 are not set.
The ignition voltage is between 11-18 volts.
The barometric pressure (BARO) is more than 68 kPa.
The fuel level is between 15-85 percent.
The estimated ambient air temperature is between 2-32°C (35.6-90°F).
The start-up ECT and estimated ambient air temperature are within 9°C (16.2°F) of each other.
The vehicle speed sensor (VSS) is less than 1.7 km/h (2 mph).
The purge solenoid valve is enabled.
DTC P0446 will attempt to run up to 10 times until it successfully completes.
DTC P0446 completes one test per trip when the above conditions have been met.