F 350 4WD Pickup V8-7.3L DSL (1988)
-Open Loop Switch
OPEN LOOP SWITCH - A normally opened or normally closed vacuum operated electric switch.
OPEN SYSTEM - Descriptive term for crankcase emissions control system which vents to the atmosphere.
OUTPUT CYCLING CHECK (OCC) - A position of the end of the "key on/engine off" test that enables energizing and de-energizing the auxiliary
output on demand.
OUTPUT STATE CHECK - A test performed in the "key on/engine off" mode after the continuous codes have been sent which forces the processor to
activate some actuators for additional diagnostics.
OVERBOOST WARNING SWITCH - Switch assembly which has a pressure switch that causes a light or buzzer to come on when turbocharger boost
pressure is excessive.
P
PART THROTTLE MODE - Same as "closed throttle mode".
PARTICULATE - A tiny bit of solid matter found in exhaust gases.
PARTS PER MILLION - A measure used in emission analyses. Abbreviation is PPM or ppm.
PCV - Abbreviation for Positive Crankcase Ventilation.
PERCOLATION - Undesirable condition during hot soak in which heat causes the air or fuel in the float bowl to expand so that fuel is forced into the
intake manifold. A properly working float bowl vent should prevent percolation.
PHOTOCHEMICAL - Term describing the action of light (photo) on air pollutants (chemicals), which creates smog.
PORTED PRESSURE SWITCH - PPS
PORTED VACUUM - Vacuum tapped from a passage just above the throttle plate in a carburetor.
Ported Vacuum Switch
PORTED VACUUM SWITCH (PVS) - A temperature actuated switch that changes vacuum connections when the coolant temperature changes.
2.3L Positive Crankcase Ventilation System
POSITIVE CRANKCASE VENTILATION SYSTEM (PCV) - An emission-control system that routes engine crankcase fumes into the intake manifold