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 section within this Computers and Control Systems Information Service Manual or consult the diagnostic/repair information for the specific vehicle being serviced.
- 2V: Two Valves per engine cylinder.
- 4V: Four Valves per engine cylinder.
- 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.
- ACP V: Air Conditioning Head Pressure Volts. A voltage input to the 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)."
- BATTEMP: 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 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 HO2S.
- 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.
- CO2: 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 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 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 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.
- FF_LRN: 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.
- FF_TEMP: 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.
- FLI V: 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 / 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, HTR22, HTRX1, HTRX2: HO2S Heater. Heater element for the HO2S sensor.
- Hydrogen: Chemical symbol H. Highly flammable gas.
- Hz: Hertz. Cycles per second.
Continued: See: I-Z
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