Part 2 of 2
ACRONYMS AND DEFINITIONSNOTE: This acronyms and definitions listing contains technical terms applicable to Ford Motor Company products. It is not intended to be an all-inclusive dictionary of components and their functions. If a detailed description of a particular system or component is desired, refer to the applicable Vehicle System for the specific vehicle being repaired.
O2S, O2S11, O2S12: Oxygen Sensor. Provides information on rich or lean exhaust conditions to the PCM.
O2S11SV, O2S12SV: Oxygen Sensor Voltage Input Pids.
OASIS: On-line Automotive Service Information System
OBD, OBD-II: On-Board Diagnostics, On-Board Diagnostics Second Generation. A system that monitors PCM input and output control signals.
On-Demand Test: The KOEO and KOER tests of the PCM and KOEO test of the TCM initialized by a technician.
OC: Oxidation Catalytic converter. A catalytic converter system that reduces the levels of HC and CO emissions.
OCT ADJ: Octane Adjust. Compensating strategy that adjusts for changes in fuel octane.
OEM: Original Equipment Manufacturer
OHC: Overhead Cam. An engine configuration that uses a single camshaft positioned above the valves.
Open Circuit: A circuit which does not provide a complete path for flow of current.
OL: Open Loop. An operating condition based on instructions not modified by PCM feedback.
OSC: Output State Control
OTM: Output Test Mode
Ozone: A blue gaseous form of oxygen (03) formed naturally by electric discharge or exposure to ultraviolet radiation.
PCM: Powertrain Control Module
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.
PIP: Profile Ignition Pickup. Provides crankshaft position information for ignition synchronization.
PIP_CTR: PIP counter
PIPTIM: Last PIP time
Potentiometer: An adjustable resistance component commonly used as a sensor (example: TP sensor).
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: Atmospheric pressure or the results obtained by a barometer.
Pressure - Differential: The pressure difference between 2 regions, such as between the intake manifold and the atmospheric pressure.
Pressure - Gauge: The amount by which the absolute pressure exceeds the atmospheric pressure.
PRNDL: Gear Selector Position
PRNDL_T: Gear Selector position TCM received PID
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.
PSC Module: Power Steering Control Module
PSR: Power Sustain Relay
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.
PZEV: Partial Zero Emission Vehicle
Quick Test: A series of diagnostic tests consisting of KOEO, KOER, and continuous memory self-tests. The resulting DTCs are retrieved using the diagnostic tool.
RAM: Random Access Memory. Memory into which information can be written as well as read.
RDI: Restraint Deployment Indicator
REDOX: Reduction Oxidation Catalytic converter. A catalytic converter system designed to operate at high temperatures.
Relay: An electromechanical device in which connections in 1 circuit are opened or closed by changes in another circuit.
Repetitive Spark: Multiple firings of individual spark plugs at engine speeds below 1,000 RPM to improve idle quality and improve emissions.
RF: Radio Frequency
RFI: Radio Frequency Interference
RFS: Returnless Fuel System
RM: Relay Module. A module containing 2 or more relays.
ROM: Read-Only Memory. Computer memory that can be accessed and used, but not altered.
RON: Research Octane Number
Routine: A group of related tasks, such as a series of diagnostic tests.
RPM: Revolutions per Minute
RPMDSD: Desired engine speed
RTN: Return. A dedicated sensor ground circuit.
RWD: Rear Wheel Drive
SAE: Society of Automotive Engineers
SCP: Standard Corporate Protocol
Self-Test: See Quick Test
Sensor: A device that detects the value or change in a physical quantity, such as temperature, pressure, or flow rate, and converts the data into an electrical signal.
SFI: Sequential Multiport Fuel Injection. A multiport fuel delivery system where each injector is individually energized and timed relative to its cylinder intake event.
Shield: A conducting sleeve that surrounds wires to be electronically isolated from electromagnetic interference (EMI).
Short Circuit: An undesirable condition in a circuit where the circuit termination is at a point other than that intended.
SHRTFT1: Short-Term Fuel Trim Bank 1. Fuel flow adjustment in response to the HO2S sensor input during closed-loop operation.
SIG RTN: Signal Return. A dedicated sensor ground circuit that is common to 2 or more sensors.
Smart Driver: A PCM or ECU output driver that can detect concerns (open or shorts) on its output circuit.
SME: Society of Manufacturing Engineers
Solenoid: A device consisting of an electrical coil which produces a magnetic field which changes the position of a metal plunger.
Stoichiometry: An air/fuel mixture that is neither too rich nor too lean. Stoichiometric ratio is 14.7 parts of air for every 1 part of fuel.
Switch: A device for making, breaking, or changing the connections in an electrical circuit.
TACH: Tachometer
TACM: Throttle Actuator Control Motor used in the ETC system.
TB: Throttle Body. A device that controls airflow through the engine via a butterfly valve and has an air bypass channel around the throttle plate.
TBCM: Traction Battery Control Module
TCM: Transaxle Control Module
TCM_CAU: Caution indicator TCM commanded on.
TCM_HAZ: Hazard indicator TCM commanded on.
TDC: Top Dead Center
Tear Tag: The 2-piece adhesive label attached to the PCM to identify its calibration.
TFT: Transmission Fluid Temperature. Indicates the temperature of transmission fluid.
TGAC: Torque of Generator AC signal
Thermistor: A temperature dependent resistor used in CHT and ECT sensors.
Timing: The relationship between spark plug firing and piston position expressed in crankshaft degrees before (BTDC) or after (ATDC) top dead center of the compression stroke.
TMAC: Torque of Motor AC signal
TORQUE: Engine torque TCM received PID
TQ_DSD: Desired Engine torque TCM received PID
TP: Throttle Position Sensor. A potentiometer that provides throttle angle and rate information for the PCM.
TP V: Throttle Position Sensor Voltage
TP_MODE: Throttle Position Mode
TP_V: Throttle Position Voltage Input
TPB: Secondary Throttle Position Voltage Input
TPREL: Lowest steady TP voltage since engine start
TR: Gear Position Indicated By Transmission Range Sensor
TR-A Sensor: Analog Transmission Range Sensor. Provides information to the PCM on the transmission range selector position.
TR_A1, TR_A2, TR_A3: TR-A 1, 2, and 3 inputs
Transducer: A device that receives energy from 1 medium and transfers it to another. For example, thermal energy is converted to an electrical signal through a temperature probe.
TRIPCNT: Number of completed OBD trips
TSB: Technical Service Bulletin. Notifies the technician of any known vehicle concerns, procedures, or general repair information.
Underspeed Mode: A control mode that prevents the engine from stalling in the event it stumbles while running. Also used during engine crank.
Vacuum: Manifold pressure that is reduced below the ambient atmospheric pressure.
Variable Reluctance: A process of passing a varying magnetic field through wire windings and inducing a voltage.
VBPWR: Vehicle Buffered Power. A PCM supplied power source that supplies regulated voltage.
VC: Vehicle Certification
VECI: Vehicle Emission Control Information label
VEHMODE: Vehicle operational mode TCM received PID
VIN: Vehicle Identification Number. A unique identification number given to every vehicle produced. Includes information about the year, model, engine, and plant origin of the vehicle.
VMV: Vapor Management Valve. Controls the flow of fuel vapors out of the carbon canister.
VPWR: Vehicle Power. A switched circuit that provides power to the EEC system. Compare Battery Voltage (B+).
VREF: Reference Voltage. A dedicated circuit that provides approximately a 5 volt signal used as a reference by certain sensors.
VSC: Vehicle System Controller
VSS: Vehicle Speed Sensor. A magnetic pickup device that generates an AC signal that is proportional to the vehicle speed.
WAC: Wide Open Throttle A/C Cut-Off. Turns the A/C system off during wide open throttle or certain other operating conditions.
WOT: Wide Open Throttle. A condition of maximum airflow through the throttle body.
Zip Tube: Another name for fresh air duct or air inlet duct.