I

IDENTIFICATION CODE - A single digit selftest service code, outputted at the beginning of the "engine running" test which is equal to onehalf of the number of engine cylinders.

IDLE VACUUM VALVE (IVV) - This device may be used in conjunction with other vacuum controls to dump thermactor air during extended periods of idle. Provides protection to the catalyst.

Ignition Barometric Pressure Switch:

IGNITION BAROMETRIC PRESSURE SWITCH - Device used to control spark timing and/or other electrical devices in response to changes in barometric pressure (i.e. altitude). In normal operation, spark timing is increased for vehicle operation above the switching point (increasing altitude) and retarded for vehicle
operation below the switching point (decreasing altitude). When controlling other electrical devices, only ON/OFF control is provided.
IGNITION DIAGNOSTIC MONITOR (IDM)
- A continuous self-test feature which senses a fault in the TFI IV Ignition module coil output signal.


IGNITION MODULE SIGNAL (IMS) - The signal produced by the ECA that controls the ignition module ON and OFF time and, therefore, the spark plug timing and coil dwell.


IGNITION PRESSURE SWITCH ASSEMBLY
- Pressure switches used on turbocharged engines in conjunction with dual mode ignition to retard spark timing during boost to prevent engine damage.


IGNITION TIMING VACUUM SWITCH - ITVS


IMCO - An improved combustion type engine exhaust emission system. Similar to engine exhaust emission systems used on GM, Chrysler and American Motors vehicles (IMproved COmbustion). A product identification name of Ford Motor Company.


INFERRED MILEAGE SENSOR (IMS) - A circuit using an E-cell which deflates its state with the application of a current. When the Ecell is completely deflated calibration parameters in the ECA are changed compensating for vehicle aging.


INFRARED ANALYZER - Instrument used to measure exhaust emissions.
INLET AIR SOLENOID (IAS) - A solenoid used to control fresh air duct/valve operation on the 1985 2.8L Ranger/Bronco II application.


INLET AIR SYSTEM (IAS) - Computer-controlled system used on the 1985 2.8L Ranger/ Bronco II models that controlled the admission of heated and ambient air into the air cleaner.