ACRONYMS AND DEFINITIONS
NOTE : 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 serviced.
2V : Two Valve engine configuration.
4V : Four Valve engine configuration.
ABS : Anti-lock Brake System.
A/C : Air Conditioning. A vehicle accessory system that modifies the passenger compartment air by cooling and dehydrating the air.
ACC : Air Conditioning Clutch. Indicates status of the A/C clutch.
ACCS : Air Conditioning Cycling Switch. Indicates status of the A/C cycling switch.
ACD : Air Conditioning Demand. A signal input to the PCM from the Air Conditioning control panel.
ACP : Air Conditioning Head Pressure or A/C cycling switch input state.
ACPSW : Air Conditioning Pressure Switch.
ACPV : Air Conditioning Head Pressure Volts. A voltage input to the Powertrain Control Module (PCM) from the ACP switch or sensor.
ACR : Air Conditioning Relay. Commanded output controlled by the PCM and acts as an A/C cutout control during heavy acceleration.
A/D : Analog-to-Digital. Analog-to-Digital signal conversion.
ADC : See ATDC.
AFCM : Alternative Fuel Control Module.
AIR : Secondary Air Injection.
AIRB : Secondary Air Injection Bypass.
Air Diverter : Air Diverter Valve. Part of the EAIR system. Diverts fresh air to the exhaust system when the electric air pump is commanded on.
AIR EVAL : Air System Evaluated. Displays a YES or NO status indicating whether the Air System has been evaluated for OBD (On-Board Diagnostic) II purposes.
Air/Fuel Ratio : Air to fuel mixture ratio. An air/fuel mixture that is 14.7:1 is also called stoichiometry.
AIRM : Secondary AIR pump monitor.
Ambient Air Temperature : Temperature of the air surrounding an object.
Analog (Electrical/Electronic) : An electrical signal that can obtain any value within the voltage limits of the signal.
ARB : Air Resource Board.
ARPMIDES: Ancillary RPM Desired. RPM required to maintain the vehicle speed commanded by Speed Control Command Switch (SCCS) inputs.
ASCII : American Standard Code for Information Interchange.
ATDC : After Top Dead Center. The location of the piston after it has reached the top of its stroke. Measured in degrees of crankshaft rotation.
AVOM : Analog Volt-Ohm Multimeter. Readings are indicated by a sweep hand on a printed scale, rather than a digital display.
AWD : All-Wheel Drive.
BARO : Barometric Pressure.
Base Idle : Idle rpm determined by the throttle lever hardset on the throttle body with the IAC solenoid disconnected.
Base Timing : Spark advance in degrees before top dead center of the base engine without any control from the PCM or ICM.
Battery Positive Voltage (B+): The positive (+) voltage from the battery or any circuit connected directly to the battery. Compare "Vehicle Power (VPWR)."
BAT TEMP : Battery Temperature.
BJB : Battery Junction Box.
BOB : Breakout Box. A test device which connects in series to the PCM and PCM harness.
BPA : Brake Pedal Applied switch. Typically located on the braking system master cylinder. Can be hydraulic or electric.
BPP : Brake Pedal Position. Indicates the position of the brake pedal, based on input from the Brake Pedal Position (BPP) switch.
BRAKE LMP or BRKL: Brake Warning Lamp Status. Activates the Brake Warning Lamp by applying voltage to the control line.
BTDC : Before Top Dead Center. The location of the piston before it has reached the top of its stroke. Measured in degrees of crankshaft rotation.
Bus + or Bus - : Multiplex circuits that carry Standard Corporate Protocol (SCP) data from module to module and to the DLC.
CAC : Charge Air Cooler. Formerly known as Intercooler. A device which lowers the temperature of pressurized intake air.
CAFE : Corporate Average Fuel Economy. A set of federal requirements and regulations which govern fuel economy standards.
CANVNT : Canister Vent Solenoid.
Catalyst : Catalytic converter. An in-line exhaust system device used to reduce the level of engine exhaust emissions.
CAT EVAL : Catalyst System Evaluated. This item indicates YES when the Catalyst Efficiency Monitor has successfully completed.
CCM : Comprehensive Component Monitor.
CCRM : Constant Control Relay Module. A relay module that provides ON-OFF control of various EEC components.
CD A through J: Coil Driver 1 through 10.
Centralized Testing Facility: State government operation. Provides Inspection/Maintenance (IM) and safety inspections.
CGND or CSE GND: Case Ground. Provides a ground source for the PCM or ECU case.
CHT : Cylinder Head Temperature. Units are displayed in either degrees Fahrenheit or Centigrade.
CHTIL : Cylinder Head Temperature Indicator Lamp.
CHTV : Cylinder Head Temperature Voltage. The actual voltage drop across the CHT sensor thermistor.
CID : Cylinder Identification. PCM input signal from Camshaft Position Sensor.
CKP : Crankshaft Position. Senses the position of the crankshaft.
CKP+, CKP- : CKP+ is the Crankshaft Position (CKP) sensor signal wire. CKP - is the signal return.
CL : Closed Loop. An operating condition or mode which enables operation based on sensor feedback.
CMP : Camshaft Position. Indicates camshaft position.
CMPFM : Camshaft Position Failure Mode. Indicates when the PCM identifies a CID/CMP fault.
CMS : Catalyst Monitor Sensor. Downstream H025.
CMVSS : Canadian Motor Vehicle Safety Standards.
CNG : Compressed Natural Gas.
CO : Carbon Monoxide. A colorless, odorless and toxic gas that is a component of auto exhaust emissions.
CO(2) : Carbon Dioxide. A colorless, odorless gas that is a normal by-product of the combustion of fuel.
Coil : A device consisting of windings around an iron core. In a spark ignition system, designed to increase voltage.
Cold Soak : Time given to a vehicle to sit at a low temperature (typically below 68°F / 20°C ) until the temperature of external and internal components stabilize.
CONT : Continuous Memory. The portion of KAM (Keep Alive Memory) used to store DTCs generated during Continuous Memory Self-Test.
Continuous Memory Self- Test : A continuous test of the EEC system conducted by the PCM whenever the vehicle is operating.
CPP : Clutch Pedal Position. Indicates clutch pedal position.
CPP Switch : Clutch Pedal Position Switch. Located on the clutch pedal and detects when the clutch pedal is depressed.
CQIS : Common Quality Indicator System.
CSE GND : Case Ground.
CT : Closed Throttle Mode. A mode when the PCM varies the pulse width of the fuel injectors to obtain the air/fuel mixture appropriate for closed throttle operation.
CTO : Clean Tach Output. Signal used to drive the instrument panel tachometer.
Data Communications Link : A communication path between various in-vehicle electronic modules. Accessed by scan tools through the Data Link Connector (DLC) .
DC : 1. Direct Current. Electric current flowing in one direction. 2. Duty Cycle. The voltage measurement of ON time versus the full cycle period, expressed in percent.
DCL : Data Communication Link.
DI : Distributor Ignition. A system in which the ignition coil secondary circuit is sequenced by a distributor.
Digital : Controls process information by switching the current or voltage ON and OFF.
DLC : Data Link Connector. J1962 connector providing access to vehicle diagnostic information.
DOHC : Dual Overhead Cam. An engine configuration that uses two camshafts positioned above the valves.
DOL : Data Output Line. A circuit that sends certain information from the PCM to the instrument cluster.
DPFEGR : Differential Pressure Feedback Exhaust Gas Recirculation. System that uses a pressure transducer to control the operation of the Exhaust Gas Recirculation (EGR) Vacuum Regulator Valve.
DRI : Deposit Resistant Injector. A fuel injector designed to prevent build-up of carbon and other unwanted deposits.
DRL : Daytime Running Lamps. A system that keeps the vehicle running lamps on at all times while the vehicle is operating.
DTM : Diagnostic Test Mode. A level of capability in an On-Board Diagnostic (OBD) system.
DTC : Diagnostic Trouble Code. An alpha/numeric identifier for a fault condition identified by the On-Board Diagnostic System.
DVOM : Digital Volt-Ohm Meter.
E-85 : Fuel containing 85% ethanol alcohol.
EAIR : Electric Secondary Air Injection. A pump-driven system for providing secondary air using an electric air pump.
EAIRM : Electric Secondary Air Pump circuit Monitor.
ECT : Engine Coolant Temperature. Displayed in either Fahrenheit or Centigrade.
ECTV : Engine Coolant Temperature Voltage. The actual voltage drop across the ECT sensor thermistor.
ECU : Electronic Control Unit. A module that handles the control strategy and monitors system inputs or outputs.
EEC : Electronic Engine Control system.
EEC-V : Fifth generation EEC system.
EFT : Engine Fuel Temperature.
EFTA : Bank 1 input. EFTA is displayed in either Fahrenheit or Centigrade.
EFTAV : Voltage drop across the EFTA (Bank 1) sensor thermistor.
EFTB : Bank 2 input. EFTB is displayed in either Fahrenheit or Centigrade.
EFTBV : Voltage drop across the EFTB (Bank 2) sensor thermistor.
EGR : Exhaust Gas Recirculation. A process in which a small amount of exhaust gas is routed into the combustion chamber.
EGR EVAL : Exhaust Gas Recirculation System Evaluated. EGR EVAL will display YES when the monitor is complete.
EGRMDSD : Electric Exhaust Gas Recirculation Motor Desired position. The PID name used to operate the Electric Exhaust Gas Recirculation (EEGR) valve with scan tool's output state control.
EGRS : EGR Shutoff. A normally closed solenoid that applies vacuum to the EGR valve when energized by the PCM.
EGRT : Exhaust Gas Recirculation Valve Temperature Sensor. A temperature sensor that is threaded into the bottom of the intake plenum.
EGR Vacuum Regulator : Controls vacuum to the EGR valve by a duty cycle signal from the PCM.
EGRVR : Exhaust Gas Recirculation Vacuum Regulator. Solenoid which varies the vacuum to the EGR valve by varying the duty cycle to the regulator.
EGRVRA : Exhaust Gas Recirculation Vacuum Regulator Actual (volt). The actual state of the commanded output.
EGRVRF : Exhaust Gas Recirculation Vacuum Regulator Fault. Represents whether a fault exists in the EGRV circuit.
EI : Integrated Electronic Ignition. An Electronic Ignition system that has the Ignition Control Module (ICM) integrated into the PCM.
EI-HDR : Electronic Ignition, High Data Rate. Formerly known as Electronic Distributorless Ignition System.
EI-LDR : Electronic Ignition, Low Data Rate. Formerly known as Distributorless Ignition System.
EMI : Electromagnetic Interference. Usually caused by ignition voltage spikes, solenoids, relay operation or noisy generator contacts.
EOL : End Of Line. A system designed specifically for use at assembly plants to make sure all new vehicles perform to design specifications.
EPA : Environmental Protection Agency (U.S. Government).
EPROM : Erasable Programmable Read-Only Memory. An electronic component in the PCM that requires the electronic storage of information.
ESOF : Electronic Shift-on-the-Fly.
EVAP : Evaporative Emissions. A system to prevent fuel vapor from escaping into the atmosphere.
EVAPCP : Evaporative Canister Purge Solenoid. Controls a solenoid which allows venting of the evaporative purge canister.
EVAPCPF : Evaporative Canister Purge Solenoid Fault. Identifies whether an electrical fault exists for the current commanded state.
EVAPCV : Evaporative Canister Vent Solenoid. Controls a solenoid which seals the EVAP system canister from atmospheric pressure during the EVAP OBD II Monitor test.
Evaporative Emissions Canister : An evaporative emission canister, containing activated charcoal which absorbs and holds fuel vapors.
EVAPPDC : Evaporative Canister Purge Duty Cycle. The duty cycle commanded to the Evap Canister Purge Solenoid by the PCM.
EVO : Electronic Variable Orifice.
EWP : Electric Water Pump.
Exciter Ring : A toothed or notched iron or steel disk, which is the moveable part of a wheel speed sensor.
FAN : Fan Speed. Used in conjunction with vehicles having multiple fan speed control. Displays OFF, LOW, or HIGH status.
FC : Fan Control.
FCS : Fuel Control Solenoid.
FCIL : Fuel Cap Off Indicator Lamp. Indicates that the fuel filler cap was not properly installed.
FEAD : Front End Accessory Drive.
FEPS : Flash Electrically Erasable Programmable Read Only Memory (EEPROM) Programming Signal. 18 volt DC signal sent by the scan tool to initiate PCM reprogramming.
FF : 1. Flexible Fuel. A system capable of using a variety of fuels for vehicle operation. 2. A PID that displays the % alcohol content in fuel.
FFLRN : Flex Fuel Learned. Displays when the PCM's Flex Fuel strategy has completed calculating the inferred alcohol content of fuel.
FFFM : Flexible Fuel Failure Mode. Indicates whether the current Flex Fuel Sensor reading (FF) is reliable or not. Displays a YES or NO.
FFTEMP : Flexible Fuel Sensor - Temperature. Alcohol concentration derived from the signal pulse width.
FFV : Flexible Fuel Vehicle.
FIFO : First In First Out.
FILO : First In Last Out.
FIM : Fuel Indicator Module.
FLI : Fuel Level Input. Used by the Evap monitor to calculate fuel tank vapor volume. Displayed as a percentage.
FLIV : Fuel Level Input Voltage.
FMEM : Failure Mode Effects Management. Operating strategy that maintains limited vehicle function in the event of a PCM or EEC component failure.
FP:1. Fuel Pump. Indicates whether the pump has been commanded ON or OFF by the PCM. 2. Fuel Pump (Modulated). Fuel pump duty cycle percentage.
FPDM: Fuel Pump Driver Module. A module that controls the electric fuel pump.
FPF : Fuel Pump Fault. Identifies whether a fault exists in the FP circuit.
FPM : Fuel Pump Monitor. Monitors the Fuel Pump I circuits for faults.
Freeze Frame : A block of memory containing the vehicle operating conditions at a specific time.
FRP : Fuel Rail Pressure. Based on FRP V.
FRP V : Fuel Rail Pressure Voltage. A voltage input to the PCM from the Fuel Rail Pressure Sensor.
FSC : Fail-Safe Cooling.
FSV : Fuel Shut-off Valve. A component of Natural Gas Vehicles. This valve either allows or prevents Natural Gas flow to the fuel rail.
FSVF : Fuel Shut-Off Valve Fault. Indicates if there is a fault in the FSV circuit. Displayed as YES or NO.
FSVM : Fuel Shut-off Valve Monitor. Monitors operation of the Fuel Shut-Off Valve / circuit.
FTP : Fuel Tank Pressure. Displayed as inches of water, kPa, or volts.
FTP V : Fuel Tank Pressure Voltage. From the FTP transducer.
FUEL PR : Fuel Pressure. Measurement of the force of the fuel delivered via the fuel pump.
FUELPW : Fuel Pulse Width. Displays the commanded pulse width at time of last data update.
FUELPW1 : Fuel Injector Pulse Width #1. Corresponds to injectors normally affected by O2S1 (HEGO1).
FUELPW2 : Fuel Injector Pulse Width #2. Corresponds to injectors normally affected by O2S2 (HEGO2).
FUELSYS : Fuel System Status (OPEN/CLOSED Loop). Formerly known as LOOP.
Fuel Tank Vapor Valve : A valve mounted in the top of the fuel tank that vents excess vapor and pressure from the fuel tank into the Evaporative Emission Control System.
FWD : Front Wheel Drive.
GEM : Generic Electronic Module.
GEN : Generator.
GENF : Generator Output Fault.
GENFDC : Generator Field Control Output.
GFS : Generator field signal monitor.
GND : Ground.
GPM : Grams Per Mile. Also known as Gallons Per Minute.
GPS : Global Positioning Satellite.
Green State Vehicle : Formally known as California Emissions. A vehicle that is equipped with California on-board diagnostics.
GSS : Gear Select Solenoid.
GVW : Gross Vehicle Weight.
Hall Effect : A process where current is passed through a small slice of semi-conductor material and a magnetic field to produce a small voltage in the semi-conductor.
Hard Fault : A fault currently present in the system.
HC : 1. Hydrocarbon. A by-product of combustion and a component of auto exhaust emissions. 2. High Compression.
HCF : Hydraulic Cooling Fan.
HCFD : Hydraulic Cooling Fan Drive.
HFC : Hydraulic Cooling Fan.
HFCF : High Fan Control Fault. Identifies if there is a fault in the HFC circuit.
HFP : High Fuel Pump.
HLOS : Hardware Limited Operating Strategy. A mode of operation where the PCM replaces output commands with fixed values in response to internal PCM malfunctions.
HO : High Output.
HO2S : Heated Oxygen Sensor. Formerly known as Heated Exhaust Gas Oxygen (HEGO) Sensor. Provides information on rich or lean exhaust conditions to the PCM.
Hot Soak : Period of time after an engine operates where localized combustion heat dissipates throughout the engine.
HTR, HTR11, HTR12, HTR21 H1R22, HTRX1, HTRX2 : HO2S Heater. Heater element for the HO2S sensor.
Hydrogen : Chemical symbol H. Highly flammable gas.
Hz : Hertz. Cycles per second.
IAC : Idle Air Control. Electrical control of throttle bypass air.
IAT : Intake Air Temperature.
IATV : Intake Air Temperature Voltage. Actual voltage drop across the IAT sensor.
IAT2 : Intake Air Temperature 2. Displayed in either Fahrenheit or Centigrade. Used on supercharged vehicles.
IAT2V : Intake Air Temperature 2 Voltage. Actual voltage drop across the IATV2 sensor.
IC : Integrated Circuit. A small Semi-Conductor device capable of doing many separate circuit functions.
ICM : Ignition Control Module. The module that controls the ignition system.
IFDM : Integrated Fuel Delivery Module.
IFS : Inertia Fuel Shutoff.
IGN GND : Ignition Ground.
Ignition : System used to provide high voltage spark for internal combustion engines.
IGNKEY(IGKY) : Ignition Key status.
IGNSW (IGSW) : Ignition Switch Position.
IMRC : Intake Manifold Runner Control. Controls airflow through the high-speed runners in the intake manifold.
IMRCM : Intake Manifold Runner Control Monitor. Monitors the IMRC / circuits for faults.
IMTV : Intake Manifold Tuning Valve. Controls airflow through runners in a split intake manifold.
INJ1, INJ2, INJ3, INJ4, INJ5, INJ6, INJ7, INJ8, INJ9, INJ1O : lnjector number or its signal output from the PCM.
Injector : A device for delivering metered pressurized fuel to the intake system or the cylinders.
Intake Air : Air drawn through a filter and distributed to each cylinder for use in combustion.
Intercooler : See CAC.
IPATS : Integrated Passive Anti-Theft System.
ISO : international Standards Organization.
KAM : Keep Alive Memory. A portion of the memory within the PCM that must have power even when the vehicle is not operating.
KAPWR : Keep Alive Power. Dedicated, unswitched power circuit that maintains KAM.
Key On Engine Off Self- Test : A test of the EEC system conducted by the PCM with power applied and the engine at rest.
Key On Engine Running Self- Test : A test of the EEC system conducted by the PCM with the engine running and the vehicle at rest.
KEYPWR : Key Power. Battery voltage supplied when the ignition key is in the ON position.
Knock : The sharp metallic sound produced when two combustion pressure fronts collide in the combustion chamber of an engine.
KOEC : Key On Engine Continuous.
KOEO : Key On Engine off.
KOER : Key On Engine Running.
KPA : Kilopascal. Unit of pressure. 3.386 kPa = 1 inch of mercury (Hg.) .
KPH : Kilometers Per Hour.
KS : Knock Sensor. Detects engine knock.
L : Liters. The unit of volume in the metric measuring system. One liter equals 1.06 quarts.
LEV : Low Emissions Vehicle.
LFC : Low Fan Control.
LFP : Low Fuel Pump. Reduced operating speed for multi-speed fuel pumps.
LIFO : Last In First Out.
LILO : Last In Last Out.
LONGFT1, LONGFT2 : Long-Term Fuel Trim. Fuel flow adjustment determined by the PCM.
LOOP : indicates OPEN or CLOSED loop status.
LPG : Liquefied Petroleum Gas.
LPLR : Low Pressure Low Resistance fuel injector.