F 250 4WD Super Duty V10-6.8L VIN S (2001)
PCM: Powertrain Control Module. Formerly known as the EEC (Electronic Engine Control) Processor.
PCV: Positive Crankcase Ventilation. A system which allows the controlled flow of crankcase vapors into the combustion chamber.
PF: Purge Flow. Amount of fuel vapor burned in the engine.
Photochemical: Term describing the action of light on air pollutants which results in creating smog.
PID: Parameter Identifier. Identifies an address in PCM memory which contains operating information.
Powertrain: Engine and transmission/transaxle components.
Pressure - Absolute: A pressure referenced to a perfect vacuum.
Pressure - Atmospheric: The pressure of the surrounding air at any given temperature and altitude. Sometimes called Barometric Pressure.
Pressure - Barometric: Pertaining to atmospheric pressure or the results obtained by a barometer.
Pressure - Differential: The pressure difference between two regions, such as between the intake manifold and atmospheric pressure.
Pressure - Gage: The amount by which absolute pressure exceeds the ambient atmospheric pressure.
PIP: Profile Ignition Pickup. Provides crankshaft position information for ignition synchronization.
Potentiometer: An adjustable resistance component commonly used as a sensor (Example: TP Sensor).
PPM: Parts Per Million. A measure used in emission analysis.
PROM: Programmable Read-Only Memory. Similar to ROM except without program instructions.
Protocol: A set of rules for the exchange of information on a network.
PSOM: Programmable Speedometer/Odometer Module. A module that processes vehicle speed information.
PSP: Power Steering Pressure. Indicates the pressure in the power steering system.
PSP V: Power Steering Pressure Input Voltage.
PTEC: Powertrain Electronic Controller.
PTO: Power Take-Off.
PW: Pulse Width. The length of time an actuator, such as a fuel injector, remains energized.
PWM: Pulse Width Modulation. Controls the intensity of an output by varying the signal duty cycle.
PWR GND: Power Ground. The main ground circuit in the EEC system.
Quick Test: A series of diagnostic tests of the EEC system consisting of KOEO, KOER and Continuous Memory Self-Tests. Results are displayed as a
series of DTCs.
RABS: Rear Antilock Brake System.
RAM: Random Access Memory. Memory into which information can be written as well as read.
REDOX: Reduction Oxidation Catalytic converter. A catalytic converter system designed to operate at high temperatures.
Regulator: Controls the alternator/generator field current to maintain proper battery charge. Contained within the PCM in smart charging applications.
Relay: An electromechanical device in which connections in one circuit are opened or closed by changes in another circuit.
REM: Rear Electronic Module.
Repetitive Spark: Multiple firings of individual spark plugs at engine speeds below 1000 RPM to improve idle quality and improve emissions.
