F 150 Heritage 2WD Pickup V8-5.4L SOHC VIN 3 (2004)
Air Diverter Solenoid: Description and Operation
AIR BYPASS SOLENOID
Secondary Air Injection Bypass Solenoid
The secondary air injection bypass (AIR bypass) solenoid (Figure 113) is used by the PCM to control vacuum to the secondary air injection diverter
(AIR diverter) valve. The AIR bypass solenoid is a normally closed solenoid. The AIR bypass solenoid also has a filtered vent feature to permit vacuum
release.