Air System

The AIR pump and solenoid is controlled by the PCM. The PCM will turn ON the AIR pump by providing the ground to complete the circuit which energizes the AIR pump/solenoid relay. When air to the exhaust ports is desired, the PCM will energize the relay to turn ON the solenoid and the AIR pump.

The PCM turns ON the AIR pump during startup any time engine coolant temperature is above 0°C (32°F). The AIR pump will operate for a maximum of 240 seconds, or until the system enters Closed Loop operation. When the PCM commands the AIR pump/solenoid relay OFF, the AIR pump will stop and the solenoid will turn off, stopping vacuum to the shut off valve. The shut off valve will close preventing any air getting to the exhaust ports.

The AIR system will be disabled under the following conditions:
^ The PCM recognizes a problem and sets a diagnostic trouble code.
^ The AIR pump has been ON for 240 seconds.
^ The Engine Speed is greater than 2825 RPM.
^ The MAP is greater than 96 kPa with VSS over 60 mph.
^ The MAP is less than 20 kPa.
^ Warm up 3-way catalytic converters over temperature detected.
^ The short and long term fuel trim are not in their normal ranges.
^ Power enrichment is detected.