2V - L

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.