Operation CHARM: Car repair manuals for everyone.

Part 1 of 2

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 repaired.

2V: Two valves per engine cylinder

3V: Three valves per engine cylinder

4V: Four valves per engine cylinder

ABS: Anti-Lock Brake System

A/C: Air Conditioning

A/CC: Air Conditioning Clutch

A/CCR: Air Conditioning Clutch Control Relay

ACCS: Air Conditioning Cycling Switch

ACDS: Air Conditioning Diagnostic Switch (refrigerant containment switch)

ACET: Air Conditioning Evaporator Temperature

ACP: Air Conditioning Head Pressure or A/C cycling switch input state

ACPSW: Air Conditioning Pressure Switch

ACPT: Air Conditioning Pressure Transducer (Switch)

A/D: Analog-to-Digital. Analog-to-Digital signal conversion.

AFCM: Alternative Fuel Control Module

AIR: Secondary Air Injection

AIRB: Secondary Air Injection Bypass

AIR EVAL: Air System Evaluated. Displays a YES or NO status indicating whether the AIR System has been evaluated for On-Board Diagnostic (OBD) purposes.

AIRM: Secondary Air Pump Monitor

APP: Accelerator Pedal Position

ARB: Air Resource Board

ASCII: American Standard Code 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.

AWD: All-Wheel Drive

BARO: Barometric Pressure

BJB: Battery Junction Box

BOB: Breakout Box. A test device which connects in series to the PCM and PCM harness.

BPA: Brake Pedal Applied

BPP: Brake Pedal Position

BPS: Brake Pedal Switch/Speed Control Deactivation

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.

CAC: Charge Air Cooler. 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.

CAN: Controller Area Network

CAT EVAL: Catalyst System Evaluated. This item indicates YES when the Catalyst Efficiency Monitor has successfully completed.

CCM: Comprehensive Component Monitor

CD A through J: Coil Driver 1 through 10

CGND: Case Ground. Provides a ground source for the PCM case.

CHT: Cylinder Head Temperature

CHTIL: Cylinder Head Temperature Indicator Lamp

CKP: Crankshaft Position

CKP+, CKP-: CKP+ is the CKP sensor signal circuit. CKP- is the signal return circuit.

CL: Closed Loop. An operating condition or mode which enables operation based on sensor feedback.

CMCV: Charge Motion Control Valve

CMP, CMP1, CMP2: Camshaft Position. CMP1 and CMP2 on V engines where applicable.

CMS: Catalyst Monitor Sensor. The downstream HO2S.

CMVSS: Canadian Motor Vehicle Safety Standards

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.

CONT: Continuous Memory. The portion of keep alive memory (KAM) used to store DTCs generated during the continuous memory self-test.

COP: Coil On Plug. Ignition coil on plug assembly.

CPP: Clutch Pedal Position

CT: Closed Throttle. A mode in which 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.

CV: Canister Vent Solenoid. A solenoid which seals the evaporative emission (EVAP) system from the atmosphere during the EVAP monitor test.

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. A communication path between various in-vehicle electronic modules.

DI: Distributor Ignition. A system in which the ignition coil secondary circuit is sequenced by a distributor.

DIS: Distributorless Ignition System. A system in which the ignition coil secondary circuit is sequenced without a distributor.

DLC: Data Link Connector. SAE standard J1962 connector providing access to vehicle diagnostic information.

DMM: Digital Multimeter

DOHC: Dual Overhead Cam. An engine configuration that uses 2 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. A 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 the build-up of carbon and other unwanted deposits.

DTM: Diagnostic Test Mode. A level of capability in an OBD system.

DTC: Diagnostic Trouble Code. An alpha/numeric identifier for a concern identified by the OBD system.

E-85: Fuel containing 85% ethanol alcohol

ECT: Engine Coolant Temperature

ECU: Electronic Control Unit. A module that handles the control strategy and monitors system inputs or outputs.

EEC: Electronic Engine Control

EEGR: Electric Exhaust Gas Recirculation (EEGR) System

EEPROM: Electrically Erasable Programmable Read-Only Memory. An electronic component in the PCM that allows the electronic storage of information.

EGR: Exhaust Gas Recirculation. A process in which a small amount of exhaust gas is routed into the combustion chamber.

EGRMC (1-4): Electric Exhaust Gas Recirculation Motor Control

EGRT: Exhaust Gas Recirculation Valve Temperature. A temperature sensor that is threaded into the bottom of the intake plenum.

EGRVR: Exhaust Gas Recirculation Vacuum Regulator. A solenoid which controls vacuum to the EGR valve by varying the duty cycle signal from the PCM.

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.

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 conform to design specifications.

EONV: Engine Off Natural Vacuum

EOT: Engine Oil Temperature

EPA: Environmental Protection Agency (United States Government)

E-Quizzer: Enhanced Quizzer

ESM: EGR System Module

ESOF: Electronic Shift-on-the-Fly

ETB: Electronic Throttle Body

ETC: Electronic Throttle Control

ETCREF: Voltage Reference (5V) for ETC (APP VREF, TP VREF).

EVAP: Evaporative Emissions. A system to prevent fuel vapor from escaping into the atmosphere.

EVAPCP: Evaporative Canister Purge Solenoid. A solenoid which controls the venting of fuel vapor from the evaporative emissions canister into the intake manifold for combustion.

EVO: Electronic Variable Orifice

EVR: Electronic Vacuum Regulator Solenoid

EWP: Electric Water Pump

FCS: Fuel Control Solenoid

FCIL: Fuel Cap Indicator Lamp. Indicates that the fuel filler cap is not correctly installed.

FEAD: Front End Accessory Drive

FEPS: Flash EEPROM Programming Signal. An 18-volt DC signal input from the diagnostic tool used by the PCM to initiate programming.

FFV: Flexible Fuel Vehicle

FLI: Fuel Level Input. Provides information on the amount of liquid fuel in the fuel tank. Used by the EVAP monitor to calculate the fuel tank vapor volume. Displayed as a percentage.

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.

FRP: Fuel Rail Pressure

FRPT: Fuel Rail Pressure Temperature

FSS: Fan Speed Sensor

FSSW: Fuel Select Switch. An output signal between the PCM and the fuel injector interface module which determines the fuel delivery mode.

FTP: Fuel Tank Pressure

FUEL PR: Fuel Pressure. Measurement of the force of the fuel delivered by the fuel pump.

FUELPW: Fuel Pulse Width. Displays the commanded pulse width at the time of the last data update.

FUELPW1: Fuel Injector Pulse Width #1. Corresponds to injectors normally affected by HO2S11.

FUELPW2: Fuel Injector Pulse Width #2. Corresponds to injectors normally affected by HO2S21.

FUELSYS: Fuel System Status (OPEN/CLOSED Loop). Formerly known as LOOP.

FWD: Front Wheel Drive

GEN: Generator

GENLI: Generator Load Input. An input signal used by the PCM to monitor charging system operation and determine the system voltage.

GND: Ground

GPM: 1. Grams per Mile. 2. Gallons per Minute.

GVW: Gross Vehicle Weight

GVWR: Gross Vehicle Weight Rating

HC: 1. Hydrocarbon. A by-product of combustion and a component of auto exhaust emissions. 2. High Compression.

HFC: High Fan Control

HLOS: Hardware Limited Operating Strategy. A mode of operation where the PCM replaces output commands with fixed values in response to internal PCM concerns.

HO: High Output

HO2S: Heated Oxygen Sensor. Provides information on rich or lean exhaust conditions to the PCM.

HTR11, HTR12, HTR13, HTR21, HTR22: HO2S Heater. Heater element for the HO2S sensor.

Hz: Hertz. Cycles per second.

IAC: Idle Air Control. Electrical control of throttle bypass air.

IAT: Intake Air Temperature

IAT2: Intake Air Temperature 2. Used on supercharged vehicles.

IC: Integrated Circuit. A small semi-conductor device capable of many separate circuit functions.

ICM: Ignition Control Module. The module that controls the ignition system.

IFS: Inertia Fuel Switch

IMRC: Intake Manifold Runner Control. Controls or modifies airflow in the intake air system.

IMRCM: Intake Manifold Runner Control Monitor. Monitors the IMRC circuits for concerns.

IMTV, IMTV1, IMTV2: Intake Manifold Tuning Valve. Controls airflow through runners in a split intake manifold.

INJ1, INJ2, INJ3, INJ4, INJ5, INJ6, INJ7, INJ8, INJ9, INJ10: Injector number or its signal output from the PCM.

IPC: Independent Plausibility Checker

ISO: International Standards Organization