Sentra L4-1597cc 1.6L DOHC MFI (GA16DE) (1991)
Idle Air Adjusting (I.A.A.) Unit
FAST IDLE CONTROL SOLENOID
There is also a fast idle control solenoid (FICD) that opens a separate passage, allowing additional air to bypass the throttle plate. It compensates
in the event the AAC valve cannot allow a sufficient amount of air through to keep the idle speed within the preset limits.