Air System

Air System:

The AIR pump and solenoid is controlled by the PCM. The PCM turns 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 energizes the relay in order to turn ON the solenoid and the AIR pump.

The PCM turns ON the AIR pump during startup any time the engine coolant temperature is above 0°C (32°F). The AIR pump operates 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 stops and the solenoid turns OFF, stopping vacuum to the shut off valve. The shut off valve closes in order to prevent any air getting to the exhaust ports.

The AIR system is 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 more than 2,825 RPM.
^ The Manifold Absolute Pressure (MAP) is more than 96 kPa with Vehicle Speed Sensor (VSS) over 96.5 km/h (60 mph).
^ The Manifold Absolute Pressure (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.