OBDII Terminology The following terms and their definitions are related to OBD2 systems. Powertrain Control Module (PCM) - The PCM is the OBD2 accepted term for the vehicle''s 'on-board computer.' In addition to controlling the engine management and emissions systems, the PCM also participates in controlling the powertrain (transmission) operation. Most PCMs also have the ability to communicate with other computers on the vehicle (ABS, ride control, body, etc.). Monitor - Monitors are 'diagnostic routines' programmed into the PCM. The PCM utilizes these programs to run diagnostic tests, and to monitor operation of the vehicle''s emissions-related components or systems to ensure they are operating correctly and within the vehicle''s manufacturer specifications. Currently, up to eleven Monitors are used in OBD2 systems. Additional Monitors will be added as the OBD2 system is further developed. Not all vehicles support all eleven Monitors. Enabling Criteria - Each Monitor is designed to test and monitor the operation of a specific part of the vehicle''s emissions system (EGR system, oxygen sensor, catalytic converter, etc.). A specific set of 'conditions' or 'driving procedures' must be met before the computer can command a Monitor to run tests on its related system. These 'conditions' are known as 'Enabling Criteria.' The requirements and procedures vary for each Monitor. Some Monitors only require the ignition key to be turned 'On' for them to run and complete their diagnostic testing. Others may require a set of complex procedures, such as, starting the vehicle when cold, bringing it to operating temperature, and driving the vehicle under specific conditions before the Monitor can run and complete its diagnostic testing. Monitor Has/Has Not Run - The terms 'Monitor has run' or 'Monitor has not run' are used throughout this manual. 'Monitor has run,' means the PCM has commanded a particular Monitor to perform the required diagnostic testing on a system to ensure the system is operating correctly (within factory specifications). The term 'Monitor has not run' means the PCM has not yet commanded a particular Monitor to perform diagnostic testing on its associated part of the emissions system. Trip - A Trip for a particular Monitor requires that the vehicle is being driven in such a way that all the required 'Enabling Criteria' for the Monitor to run and complete its diagnostic testing are met. The 'Trip Drive Cycle' for a particular Monitor begins when the ignition key is turned 'On.' It is successfully completed when all the 'Enabling Criteria' for the Monitor to run and complete its diagnostic testing are met by the time the ignition key is turned 'Off.' Since each of the eleven monitors is designed to run diagnostics and testing on a different part of the engine or emissions system, the 'Trip Drive Cycle' needed for each individual Monitor to run and complete varies. OBD2 Drive Cycle - An OBD2 Drive Cycle is an extended set of driving procedures that takes into consideration the various types of driving conditions encountered in real life. These conditions may include starting the vehicle when it is cold, driving the vehicle at a steady speed (cruising), accelerating, etc. An OBD2 Drive Cycle begins when the ignition key is turned 'On' (when cold) and ends when the vehicle has been driven in such a way as to have all the 'Enabling Criteria' met for all its applicable Monitors. Only those trips that provide the Enabling Criteria for all Monitors applicable to the vehicle to run and complete their individual diagnostic tests qualify as an OBD2 Drive Cycle. OBD2 Drive Cycle requirements vary from one model of vehicle to another. Vehicle manufacturers set these procedures. Consult your vehicle''s service manual for OBD2 Drive Cycle procedures. Do not confuse a 'Trip' Drive Cycle with an OBD2 Drive Cycle. A 'Trip' Drive Cycle provides the 'Enabling Criteria' for one specific Monitor to run and complete its diagnostic testing. An OBD2 Drive Cycle must meet the 'Enabling Criteria' for all Monitors on a particular vehicle to run and complete their diagnostic testing. Warm-up Cycle - Vehicle operation after an engine off period where engine temperature rises at least 40 F (22 C) from its temperature before starting, and reaches at least 160 F (70 C). The PCM uses warm-up cycles as a counter to automatically erase a specific code and related data from its memory. When no faults related to the original problem are detected within a specified number of warm-up cycles, the code is erased automatically. The following terms and their definitions are related to OBD 1 systems. A - Amperes A/C - Air Conditioning A/CL BIMET - Air Cleaner Bi-Metal Sensor A/CL DV - Air Cleaner Duct and Valve Vacuum Motor A/D - Analog to Digital Converter A/F - Air Fuel Ratio A/T - Automatic Transmission A4R70W - Automatic Overdrive Electronic Wide Ration Transmission AAC - Auxiliary Air Control Valve AAV - Anti-Afterburn Valve (Mazda) ABCV - Airbleed Control Valve (Ford) ABS - Antilock Brake System ABSV - Air Bypass Solenoid Valve (Mazda) ABV - Air Bypass Valve AC - Alternating Current ACC - Air Conditioning Clutch ACC - Automatic Climate Control ACCS - A/C Cycling Clutch Switch ACD - Air Conditioning Demand Switch ACON - Air Conditioning On Signal ACP - Air Conditioning Pressure Signal ACPSW - Air Conditioning Pressure Switch ACR - Air Conditioning Relay ACR4 - Air Conditioning Refrigerant, Recovery, Recycling, Recharging ACT - Air Charge Temperature ACV - Air Control Valve ADU - Analog-Digital Unit AFC - Air Flow Control AFM - Air Flow Meter AFR - Air Fuel Ratio AFS - Air Flow Sensor (Mitsubishi) AIR - Secondary Air Injection System AIRB - Air Bypass Solenoid AIRD - AIR Diverter Solenoid AIS - Air Injection System (Chrysler) AIS - Automatic Idle Speed AIV - Air Injection Valve ALC - Automatic Level Control ALCL - Assembly Line Communications Link (GM) ALDL - Assembly Line Data Link ALT - Alternator (replaced with GEN) AM1 - Air Management 1, AIR Bypass AM2 - Air Management 2, AIR Diverter AMB - Ambient AOD - Automatic Overdrive AODE - Automatic Overdrive Electronic Transmission AODE-W - Automatic Overdrive Electronic Wide (ratio transmission) AP - Accelerator Pedal APC - Automatic Performance Control APS - Atmospheric Pressure Sensor (Mazda) APS - Absolute Pressure Sensor (GM) APT - Adjustable part Throttle ARC - Automatic Ride Control ARS - Automatic Restraint System ASARC - Air Suspension Automatic Ride Control ASD - Automatic Shutdown Relay ASDM - Airbag System Diagnostic Module (Chrysler) ASE - Automotive Service Excellence ASM - Acceleration Simulation Mode ASR - Acceleration Slip Regulation ATC - Automatic Temperature Control ATDC - After Top Dead Center ATF - Automatic Transmission Fluid ATM - Actuator Test Mode ATS - Air Temperature Sensor (Chrysler) ATX - Automatic Transaxle AVOM - Analog Volt / Ohm Meter AWD - All-Wheel Drive AWD - All Wheel Drive AWG - American Wire Gage'' AX4S - Automatic 4-Speed Trans. AXOD - Automatic Overdrive Transaxle AXOD-E - Automatic Overdrive Transaxle - Electronically Controlled B/MAP - Barometric/Manifold Absolute Pressure B+ - Battery Positive Voltage BAC - Bypass Air Control Valve BARO - Barometric Pressure BAT - Battery BC - Blower Control BCM - Body Control Module BHP - Brake Horsepower BHS - Bimetal Heat Sensor (Ford) BID - Breakerless Inductive Discharge (AMC) BLM - Block Learn Multiplier (replaced with LT FUEL TRIM) BMAP - Barometric/Manifold Absolute Pressure Sensor (Ford) BOB - Breakout Box BOO - Brake On / Off Switch BP - Barometric Pressure BPA - Mechanical Bypass Air BPCSV - Bypass Control Solenoid Valve BPP - Brake Pedal Position Switch BPS - Back Pressure Sensor BPT - Back-Pressure Transducer BPV - Bypass Valve (Ford) BPW - Brake Pulse Width BSV - Backfire Suppressor (Ford) BTDC - Before Top Dead Center BTS - Battery Temperature Sensor BTSI - Brake Transmission Shift Interlock Btu - British Thermal Unit BUS N - Bus Negative BUS P - Bus Positive BV - Bowl Vent Port (Ford) BVSV - Bi-Metal Vent Control Valve BVT - Backpressure Variable Transducer System (Ford) C - Carbon C - Celsius C.A.R.B. - California Air Resource Board C3 - Computer Command Control System (GM) C3I - Computer Controlled Coil Ignition C4 - Computer Controlled Catalytic Converter System (GM) CAC - Charge Air Cooler CANP - EVAP Canister Purge Solenoid CARB - Carburetor CAS - Clean Air System CAS - Crank Angle Sensor CASE - Cranking Angle Sensing Error CBD - Closed Bowl Distributor CC - Catalytic Converter CC - Cruise Control CC - Cubic Centimeters CC - Climate Control CCC - Converter Clutch Control CCC - Computer Command Control System (GM) CCD - Computer Controlled Dwell CCD - Chrysler Collision Detection CCDIC - Climate Control Driver Information Center CCEI - Coolant Controlled Idle Enrichment (Chrysler) CCEV - Coolant Controlled Engine Vacuum Switch (Chrysler) CCM - Central Control Module CCM - Continuous Component Monitor CCNT, DTC CCNT - Count Code CCO - Converter Clutch Override CCOT - Cycling Clutch Orifice Tube CCP - Climate Control Panel CCP - Controlled Canister Purge (GM) CCRM - Constant Control Relay Module CCS - Coast Clutch Solenoid CCSP - Carbon Canister Storage/Purge CCV - Canister Control Valve CDCV - Canister Drain Cut Valve CDI - Capacitor Discharge Ignition (AMC) CDR - Chrysler Diagnostic Readout CDRV - Crankcase Depression Regulator Valve CE - Commutator End CEAB - Cold Engine Air Bleed CEC - Crankcase Emission Control System (Honda) CECU - Central Electronic Control Unit (Nissan) CEL - Check Engine Light CER - Cold Enrichment Rod (Ford) CES - Clutch Engage Switch CESS - Cold Engine Sensor Switch CFC - Chlorofluorocarbons CFI - Central Fuel Injection CFI - Continuous Fuel Injection CFM - Cubic Feet Per Minute CFV - Critical Flow Venturi CHM - Cold Mixture Heater CID - Cylinder Identification Signal CID - Cubic Inch Displacement CIS - Continuous Injection System (Bosch) CKP - Crankshaft Position Sensor CKP REF - Crankshaft Position Reference CKT - Circuit CL - Closed Loop CLC - Converter Lockup Clutch (replaced with TCC) CLCC - Closed Loop Carburetor Control CLNT - Coolant CLV - Calculated Load Value CMFI - Central Multi-port Fuel Injection CMP - Camshaft Position Sensor CMP REF - Camshaft Position Reference CO - Carbon Monoxide CO2 - Carbon Dioxide COC - Conventional Oxidation Catalyst (Ford) COP - Coil On Plug Electronic Ignition CP - Canister Purge (GM) CP - Crankshaft Position Sensor (Ford) CPA - Connector Position Assurance CPI - Central Port Fuel Injection CPP - Clutch Pedal Position CPS - Central Power Supply CPSOV - Canister Purge Shut Off Valve (Ford) CPU - Central Processing Unit CRK - Cranking Signal CRT - Cathode Ray Tube CSC - Coolant Spark Control (Ford) CSE GND - PCM Case Ground CSSA - Cold Start Spark Advance System (Ford) CSSH - Cold Start Spark Hold System (Ford) CTAV - Cold Temperature Actuated Vacuum Switch (Ford) CTM - Central Timer Module CTO - Clean Tachometer Output CTO - Coolant Temperature Override CTOX - Continuous Trap Oxidizer CTP - Closed Throttle Position CTS - Charge Temperature Switch (Chrysler) CTS - Coolant Temperature Sensor CTVS - Closed Throttle Vacuum Switch CV - Constant Velocity CV - Control Valve CVCC - Compound Vortex Controlled Combustion System (Honda) CVR - Control Vacuum Regulator (Ford) CVS - Constant Volume Sampler CWM-Ford - Cold Weather Modulator (Ford) DAB - Delayed Accessory Bus dB - Decibels DC - Duty Cycle DC - Direct Current DCISCA - DC Motor Idle Speed Actuator DCL - Data Communication Link DDL - Diagnostic Data Link DE - Drive End DEC - Digital Electronic Controller DEFI - Digital Electronic Fuel Injection (Cadillac) DEPS - Digital Engine Position Sensor DERM - Diagnostic Energy Reserve Module DFCO - Decel Fuel Cutoff Mode DFI - Direct Fuel Injection DFS - Decel Fuel Shutoff DI - Direct Ignition DI - Distributor Ignition (System) DIC - Driver Information Center DICM - Distributor Ignition Control Module DIS - Direct Ignition (Waste Spark) DLC - Data Link Connector (OBD) DM - Drive Motor DMCM - Drive Motor Control Module DMCT - Drive Motor Coolant Temperature DMPI Module - Drive Motor Power Inverter Module DMS - Distributor Modulator System DOHC - Dual Overhead Cam DOL - Data Output Line to IPC DPC - Dynamic Pressure Control DPFE - Differential Pressure Feedback DPI - Fuel Plug Inhibit DRB II - Diagnostic Readout Box (Chrysler) DRCV - Distributor Retard Control Valve DRL - Daytime Running Lights DSO - Digital Storage Oscilloscope DSR - Ford Diagnostic Subroutine DSS - Downshift Solenoid DSSA - Dual Signal Spark Advance (Ford) DSV - Deceleration Solenoid Valve DTC - Diagnostic Trouble Code DTC FRZ - Diagnostic Trouble Code Freeze Frame DTM - Diagnostic Test Mode DTVS - Dual Temperature Vacuum Switch DV - Delay Valve DVAC - Distributor Vacuum Advance Control Valve DVDSV - Differential Vacuum Delay and Separator Valve DVDV - Distributor Vacuum Delay Valve DVOM - Digital Volt-Ohmmeter DV-TW - Relay Valve Two Way DVVV - Distributor Vacuum Vent Valve E4OD - Electronic 4-Speed Overdrive EAC - Electronic Air Control (replaced with AIR) EACV - Electronic Air Control Valve EAIR - Electronic Secondary Air Injection EBCM - Electronic Brake Control Module EBP - Exhaust Back: Pressure EBTCM - Electronic Brake T/C Module EC - Engine Control ECA - Electronic Control Assembly (Ford) ECC - Electronic Climate Control ECCS - Electronic Concentrated Control System ECI - Extended Compressor at Idle ECIT - Electronic Control Ignition Timing ECL - Engine Coolant Level ECM - Engine/Electronic Control Module ECS - Evaporation Control System (Chrysler) ECS - Emission Control System ECT - Engine Coolant Temperature ECU - Electronic Control Unit EDF - Electro-Drive Fan EDIS - Electronic Direct Ignition System (replaced with EI) EDM - Electronic Distributor Modulator (Ford) EEC - Electronic Engine Control (Ford) EEC-I - Control of Ignition Timing EEC-II - Control of Ignition Timing and Fuel Delivery Through a Feed Carburetor System EEC-III - Control of Ignition Timing and Fuel Delivery Through a Central Fuel Injection System EEC-IV - Control of Ignition Timing and Fuel Delivery Through an Electronic Fuel Injection System EECS - Evaporative Emission Control System EEGR - Electronic EGR (Solenoid) EEGR Monitor - Electronic EGR Test EEPROM - Electronically Erasable Programmable Read Only Memory EESS - Evaporative Emission Shed System (Ford) EEVIR - Evaporator Equalized Values in Receiver EFC - Electronic Fuel Control EFC - Electronic Feedback Carburetor (Chrysler) EFCA - Electronic Fuel Control Assembly (Ford) EFE - Early Fuel Evaporation EFI - Electronic Fuel Injection EFT - Engine Fuel Temperature EFV - Early Fuel Evaporation EGC - Exhaust Gas Check Valve (Ford) EGO - Exhaust Gas Oxygen Sensor (Ford) EGOR - EGO Signal Return (Ford) EGR - Exhaust Gas Recirculation EGR Monitor - OBDII EGR Test EGR TVV - Exhaust Gas Recirculation Thermal Vacuum Valve EGRB - EGR Boost Sensor EGRC - EGR Control Solenoid (Ford) EGRC-BPT - EGR Control Back Pressure Transducer EGRPS - EGR Valve Position Sensor (Mazda) EGRT - Exhaust Gas Recirculation Temperature EGRV - Exhaust Gas Recirculation Vent Solenoid EGTS - Exhaust Gas Temperature Switch (replaced with EGRT) EH - Electro-Hydraulic EI - Integrated Electronic Ignition System EICV - Electronic Idle Control Valve ELB - Electronic Lean Burn (Chrysler) ELC - Electronic Level Control ELCD - Evaporative Loss Control Device EM - Engine Modification EMB - Electromagnetic Brakes EMF - Electromotive Force (voltage) EMI - Electromagnetic Interference EMR - Electronic Module Retard EN - Generator (Alternator) EOBD - European On Board Diagnostics EOP - Engine Oil Pressure EOS - Exhaust Oxygen Sensor EOT - Engine Oil Temperature EP - Exhaust Pressure EPA - Environmental Protection Agency EPC - Electronic Pressure Control EPOS - EGR Valve Position Sensor (Ford) EPROM - Erasable Programmable Read Only Memory EPT - EGR Pressure Transducer (replaced with PFE) ESA - Electronic Spark Advance (Chrysler) ESC - Electronic Spark Control System (Ford) ESD - Electrostatic Discharge ESS - Electronic Spark Selection (Cadillac) EST - Electronic Spark Timing ETC - Electronic Temperature Control ETP - EGR Pressure Transducer ETR - Electronically Tuned Receiver EVAP - Evaporative Emissions System EVAP CP - Evaporative Canister Purge EVAP CV - Evaporative Emissions System Canister Vent EVIC - Electronic Vehicle Information Center EVO - Electronic Vehicle Orifice EVP - EGR Valve Position Sensor EVR - EGR Vacuum Regulator EXH - Exhaust F4WD - Full Time Four Wheel Drive FAN - Cooling Fan (Low or High Speed) FBC - Feedback Carburetor FBCA - Feedback Carburetor Actuator (Ford) FC - Fan Control FCA - Fuel Control Assembly (Chrysler) FCS - Fuel Control Solenoid (Ford) FDBK - Feedback FDC - Fuel Deceleration Valve (Ford) FDV - Fuel Decel Valve (Ford) FEEPROM - Flash Electronically Erasable Programmable Read Only Memory FEPROM - Flash Erasable Programmable Read Only Memory FF - Flexible Fuel FI - Fuel Injector FIC - Fast Idle Control FICD - Fast Idle Control Device FIPL - Fuel Injection Pump Lever FLC - Fluid Lock-up Converter (Ford) FLS - Fluid Level Sensor (GM) FM - Fan Motor Program in PCM FMEM - Failure Mode Effect Management FMVSS - Federal Motor Vehicle Safety Standards FOM - Fix Operating Mode (Limp Mode) FP - Fuel Pump Relay (Ford) FP - Fuel Pump FPM - Fuel Pump Monitor (in PCM) FPRC - Fuel Pump Regulator Control FRC - Forced FRP - Fuel Rail Pressure FRT - Fuel Rail Temperature FRZ - Freeze Frame FT - Fuel Trim FTL - Fuel Tank Level Sensor FTO - Filtered Tachometer Output FTP - Fuel Tank Pressure FTT - Fuel Tank Temperature FWD - Front Wheel Drive g/sec - Grams per Second GA - Gage GCM - Governor Control Module GCW - Gross Combination Weight GDC - Fuel Data Center GDI - Gasoline Direct Injection GEM - Generic Electronic Module GEN - Generator (Alternator) GND - Electrical Ground Connection GOOSE - Brief Throttle Open/Close GPM - Grams Per Mile GPS - Governor Pressure Sensor GST - Generic Scan Tool GVW - Gross Vehicle Weight H - Hydrogen H/CMPR - High Compression H2O - Water HAC - High Altitude Compensator HAIS - Heated Air Intake System (Chrysler) HBV - Heater Blower Voltage HC - Hydrocarbons HCDS - High Clutch Drum Speed HCV - Hydrocarbon (Ford) HCV - Exhaust Heat Control Valve (Ford) HD - Heavy Duty HDC - Heavy Duty Cooling HDR-CKP - High Data Rate CKP Sensor HEGO - Heated Exhaust Gas Oxygen Sensor HEI - High Energy Ignition (GM) HFC - High (speed) Fan Control HFP - High Fuel Pump (Relay) Control Hg - Mercury HIC - Hot-Idle Compensator (Ford) HLOS - Hardware Limited Operation System HO - High Output HO2S - Heated Oxygen Sensor HO2S-1-1 - Bank One Sensor One Signal HO2S-1-2 - Bank One Sensor Two Signal HO2S-1-3 - Bank One Sensor Three Signal HO2S-2-1 - Bank Two Sensor One Signal HO2S-2-2 - Bank Two Sensor Two Signal hp - Horsepower HPC - High Pressure Cutoff HPL - High Pressure Liquid HPS - High Performance System HPV - High Pressure Vapor HSC - High Swirl Combustion HT - High Tension HUD - Heads Up Display HVAC - Heater Ventilation and Air Conditioning HVACM - Heater-Vent-Air Conditioning Module HVS - High Voltage Switch Hz - Hertz I/M - Inspection and Maintenance I/O - Input / Output I/P - Instrument Panel IA - Intake Air IAC - Idle Air Control (motor or solenoid) IACV - Idle Air Control Valve IAS - Inlet Air Solenoid (Ford) IAT - Intake Air Temperature IBP - Integral Back Pressure IC - Integrated Circuit IC - Ignition Control ICM - Ignition Control Module ICP - Injection Control Pressure ICS - Idle Control Solenoid (GM) ID - Inside Diameter IDI - Integrated Direct Ignition IDL - Idle Position Switch IDM - Ignition Diagnostic Monitor IDM - Injector Driver Module IFI - Indirect Fuel Injection IFS - Inertia Fuel Switch IGN - Ignition IGN ADV - Ignition Advance IGN GND - Ignition Ground ILC - Idle Load Compensator IMA - Idle Mixture Adjuster IMRC - Intake Manifold Runner Control IMS - Ignition Module Signal IMS - Inferred Mileage Sensor (Ford) IMT - Intake Manifold Timing INJ 1 to INJ 10 - Fuel Injectors 1 to 10 INT - Integrator (replaced with ST FUEL TRIM) IPC - Instrument Panel Cluster IPR - Injector Pressure Regulator IRCM - Integrated Relay Control Module ISA - Idle Speed Actuator ISC - Idle Speed Control ISO - International Standard of Organization ISS - Input Shaft Speed ITA - Ignition Timing Adjustment ITCS - Ignition Timing Control System (Honda) ITS - Idle Tracking Switch IVS - Idle Validation Switch IVSC - Integrated Vehicle Speed Control IVV - Idle Vacuum Valve (Ford) JAS - Jet Air System (Mitsubishi) JSV - Jet Mixture Solenoid Valve KAM - Keep Alive Memory KAPWR - Direct Battery Power KD - Kickdown KDLH - Kickdown Low Hold Kg/cm2 - Kilograms/ Cubic Centimeters kHz - Kilohertz Km - Kilometers KOEC - Key On, Engine Cranking KOEO - Key On, Engine Off KOER - Key On, Engine Running KPA - Kilopascal KS - Knock Sensor KSM - Knock Sensor Module L - Liters L4 - Four Cylinder Inline Engine LAMBSE - Short Term Fuel Trim LCD - Liquid Crystal Display LED - Light Emitting Diode LFC - Low Fan Control LFP - Low Speed Fuel Pump Control LHD - Left Hand Drive LOAD - Calculated Load Value LOC - Light Off Catalyst LONGFT - Long Term Fuel Trim LOOP - Engine Operating Loop Status LOS - Limited Operating Strategy LPG - Liquid Petroleum Gas LSS - Linear Shift Solenoid LTFT - Long Term Fuel Trim LTS - Low Coolant Switch LUS - Lock-Up Solenoid LV8 - Load Variable LWB - Long Wheel Base M/C - Mixture Control M/T - Manual Transmission MAF - Mass Air Flow Sensor MAF RTN - Mass Airflow Sensor Ground MAP - Manifold Absolute Pressure Sensor MAS - Mixture Adjust Screw MAT - Manifold Air Temperature MC - Mixture Control MCS - Mixture Control Solenoid (GM) MCT - Manifold Charge Temperature Sensor (Ford) MCU - Microprocessor Control Unit (Ford) MCV - Manifold Control Valve (Ford) MDP - Manifold Differential Pressure MECS - Mazda Electronic Control System MEMCAL - Memory Calibration MFI - Multiport Fuel Injection MIC - Mechanical Instrument Cluster MIL - Malfunction Indicator Lamp MISAR - Microprocessed Sensing and Automatic Regulation (GM) MLP - Manual Lever Position MLUS - Modulated Lock Up Solenoid or its Control Circuit (Ford) MLVLPS - Manual Valve Lever Position MPFI - Multi-Port Fuel Injection MPG - Miles Per Gallon MPH - Miles Per Hour MPI - Multi Port Injection mS or ms - Millisecond MSFF - Miles Since First Fail MSLF - Miles Since Last Fail MST - Manifold Surface Temperature MT - Manual Transmission MTV - Manifold Tune Valve mV or mv - Milivolt MVLPS - Manual Valve Lever Position MVZ - Manifold Vacuum Zone N - Nitrogen N.C. - Normally Closed Position N.O. - Normally Open Position N/MIL - A Code Set Without a MIL Request N/V - Input Shaft Speed to Vehicle Speed NDIR - Non Dispersive Infrared NDS - Neutral Drive Switch NGS - Neutral Gear Switch (Ford) NGV - Natural Gas Vehicles Nm - Newton Meters NOx - Oxides of Nitrogen NTC - Negative Temperature Coefficient NVRAM - Non Volatile Random Access Memory O2 - Oxygen O2S-11 - Oxygen Sensor Signal (Bank 1) O2S-21 - Oxygen Sensor Signal (Bank 2) OASIS - Ford Motor Company Online Automotive Service Information System OBD I - On Board Diagnostics Version I OBD II - On Board Diagnostics Version II OBD STAT - On Board Diagnostic System Status OC - Oxidation Catalytic Converter OCC - Output Circuit Check (Ford) OCIL - Overdrive Cancel Indicator Lamp OCS - Overdrive Cancel Switch OCT ADJ - Octane Adjust Fuel Switch OD - Overdrive OD - Outside Diameter ODM - Output Device Monitor ODS - Overdrive Drum Speed OE - Original Equipment OEM - Original Equipment Manufacturer OHC - Overhead Cam Engine OHV - Over Head Valve OL - Open Loop ORC - Oxidation Reduction Converter OS - Oxygen Sensor OSAC - Orifice Spark Advance Control (Chrysler) OSC - Output State Check (Ford) OSM - Output State Monitor OSS - Output Speed Shaft OTIS - Overhead Travel Information System OVCV - Outer Vent Control Valve P/B - Power Brakes P/E - Power Enrichment P/N - Part Number P/S - Power Steering PA - Pressure Air (Honda) PAFS - Pulse Air Feeder System (Chrysler) PAIR - Pulsed Secondary Air Injection PAS - passive Anti-Theft System PAS - Power Assisted Steering PASS - Personalized Automotive Security System PC - Pressure Control PCB - Printed Circuit Board PCI - Programmable Communications Interface PCM - Powertrain Control Module PCS - Pressure Control Solenoid PCV - Positive Crankcase Ventilation PECV - Power Enrichment Control Valve PF - Purge Flow Sensor PFE - Pressure Feedback EGR Sensor PFI - Port Fuel Injection PFI - Port Fuel Injection (GM) PGM-FI - Programmed Gas Management Fuel Injection (Honda) PID - Parameter Identification Location PID SUP - Parameter Identification Supported PIP - Profile Ignition Pickup Signal PIV - Peak Inverse Voltage PKE - Passive Keyless Entry PMD - Pump Mounted Driver PNP - Par Neutral Position POT - Potentiometer PPM - Parts Per Minute PPS - Ported Pressure Switch (Ford) PR - Pressure Relief PRC - Pressure Regulator Control PRNDL - Switch PROM - Programmable Read-Only Memory PS - Power Steering PSA - Pressure Switch Assembly PSC - Power Steering Control PSI - Pounds Per Square Inch PSOM - Programmable Speedometer Odometer Module PSOV - Purge Shut Off Valve (Ford) PSP - Power Steering Pressure PSPS - Power Steering Pressure Switch PTC - Positive Temperature Coefficient Resistor PTO - Power Take Off (4WD Option) PTOX - Periodic Trap Oxidizer PTU - Part Throttle Unlock PVA - Ported Vacuum Advance PVS - Ported Vacuum Switch PWM - Pulse Width Modulation PWR GND - Power Ground for PCM QDM - Quad Driver Module RABS - Rear Antilock Brake System RAM - Random Access Memory RAP - Retained Access Power RECAL - Calibration Adjustment REDOX - Reduction Oxidation Converter REF - Reference RFI - Radio Frequency Interference RHD - Right Hand Drive RKE - Remote Keyless Entry RM - Relay Module ROM - Read Only Memory RON - Rated Octane Number RPM - Revolutions Per Minute RRS - Variable Reluctance Sensor RTD - Real Time Dampening RTN - Dedicated Sensor Ground Circuit RTV - Room Temperature Vulcanizing RVP - Reid Vapor Pressure RWAL - Rear Wheel Anti-Lock RWD - Rear Wheel Drive S4WD - Selectable Four Wheel Drive SAE - Viscosity Grade SA-FV - Separator Assembly Fuel/Vacuum SAVM - Spark Advance Vacuum Modulator SAW - Spark Angle Work SBDS - Service Bay Diagnostic System SBEC - Single Board Engine Controller (replaced with PCM0 SBS - Boost Solenoid (Ford) SBT - Serial Bus Traveler SC - Supercharged Engine SCAP - Silicone Capacitance Absolute Pressure Sensor (Ford) SCB - Supercharger Bypass SCC - Spark Control Computer (Chrysler) SCP - Standard Corporate Protocol SDI - Saab Direct Ignition SDM - Sensing Diagnostic Module SDV - Spark Delay Valve SDV - Spark Deceleration Valve SEFI - Sequential Electronic Fuel Injection SEO - Special Equipment Option SES - Service Engine Soon (replaced with MIL) SFI - Sequential Fuel Injection SHED - Sealed Housing Evaporative Determination System SHO - Super High Output Engine SHRT FT - Short Term Fuel Trim SHRTFT1 - Short Term Fuel Trim Bank 1 SIG RTN - Signal Return (sensor ground) SIL - Shift Indicator Lamp SIPS - Side Impact Protections System SIR - Supplemental Inflatable Restraint SIS - Solenoid Idle Stop SMEC - Single Module Engine Controller (replaced with PCM) SMPI - Sequential Multiport Fuel Injection (Chrysler) SO2 - Sulfur Dioxide SOHC - Single Overhead Cam SPD - Speed SPFI - Single Point Fuel Injection (throttle body) SPI - Serial Peripheral Interface SPL - Smoke Puff Limiter SPOUT - Spark Output Signal SPS - Service Programming System SRC - Selective Ride Control SRDV - Spark Retard Delay Valve SRI - Service Reminder Indicator SRS - Spark Retard Solenoid SRS - Supplemental Restraint System (air bag) SRT - System Readiness Test SS - Speed Sensor (Honda) SS1, SS2,etc. - Shift Solenoid 1, 2, etc. SSI - Solid State Ignition (Ford) ST - Scan Tool STAR - Self Test Automatic Readout STI - Self Test Input STI - Self-Test Input (Ford) STO - Self Test Output STO - Self-Test Output (Ford) STS - Service Throttle System (lamp) SUSP - Suspension System Module SVV - Solenoid Vent Valve (Ford) SWB - Short Wheel Base TA - Temperature Air (Honda) TAB - Thermactor Air Bypass TAC - Throttle Actuator Control TAC - Thermostatic Air Cleaner (GM) TACH - Tachometer TAD - Thermactor Air Diverter TAP - Transmission Adaptive Pressure TAV - Temperature Actuated Vacuum TBI - Throttle Body Injection TC - Turbocharger TCA - Thermostat Controlled Air Cleaner TCC - Torque Converter Clutch TCCP - Torque Converter Clutch Pressure TCCS - Toyota Computer Controlled System TCIL - Transmission Control Indicator Lamp TCM - Transmission Control Module TCP - Torque Charger TCP - Temperature Compensated Accelerator Pump (Ford) TCS - Traction Control Switch TCS - Transmission Control Switch TCS - Transmission Controlled Spark (GM) TD - Turbo Diesel TDC - Top Dead Center TDI - Turbo Direct Injection TE - Thermal Expansion TFP - Transmission Fluid Pressure TFP - Throttle Fluid Pressure TFT - Transmission Fluid Temperature THM - Turbo Hydra-Matic TI - Transistorized Ignition System TIC - Thermal Ignition Control (Chrysler) TIV - Thermactor Idle Vacuum Valve (Ford) TK - Throttle Kicker Actuator (Ford) TKS - Throttle Kicker Solenoid TOT - Transmission Oil Temperature TP - Throttle Position TP Mode - Throttle Position Mode TPCV - Tank Pressure Control Valve TPI - Tuned Port Injection TPM - Tire Pressure Monitor TPP - Throttle Position Potentiometer TPS - Throttle Position Sensor TPT - Throttle Position Transducer (Chrysler) TR - Transmission Range Sensor TRLHP - Thermal Vacuum Valve TRS, TRS+1 - Transmission Regulated Spark Control System TSB - Technical Service Bulletin TSP - Throttle Solenoid Positioner (Ford) TSS - Transmission Shaft Speed Sensor TSS - Turbine Speed Shaft Sensor TV - Throttle Valve TVS - Temperature Vacuum Switch TVV - Thermal Vent Valve (Ford) TWC - Three Way Catalyst TWC + OC - Three Way Catalyst UART - Universal Asynchronous Receiver-Transmitter UD - Underdrive UIDI - Up-Integrated Direct Ignition V - Volts VAC - Vacuum VAF - Vane Airflow Meter VAF - Volume Air Flow VAT - Vane Air Temperature Sensor VATS - Vehicle AntiTheft System VBAT - Vehicle (system) Battery Voltage VCC - Vacuum Cut Control Solenoid VCM - Vehicle Control Module VCRM - Variable Control Relay Module VCTS - Vacuum Control Temperature Sensing Valve (Ford) VCV - Vacuum Control Valve (Ford) VDOT - Variable Displacement Orifice Tube VDV - Vacuum Delay Valve VDV - Vacuum Differential Valve (Ford) VECI - Vehicle Emission Control Information Decal VF - Vacuum Fluorescent VIM - Vehicle Interface Module VIN - Vehicle Identification Number VIS - Variable Induction System VLCM - Variable Load Control Module VMV - Vapor Management Valve (EVAP) VMV - Vacuum Modulator Valve VNT - Variable Nozzle Turbocharger VOTM - Vacuum Operated Throttle Modulator (Ford) VPWM - Variable Pulse Width Modulated VPWR - Ignition Switched Power VR - Voltage Regulator VR/S - Vacuum Regulator/Solenoid (Ford) VRDV - Vacuum Retard Delay Valve (Ford) VREF - Reference Voltage (from PCM) VRESER - Vacuum Reservoir (Ford) VREST - Vacuum Restrictor (Ford) VRIS - Variable Resonance Induction System VRS - Variable Reluctance Sensor VRV - Vacuum Regulator Valve (Ford) VSS - Vehicle Speed Sensor VVA - Venturi Vacuum Amplifier (Ford) VVC - Variable Voltage Choke (Ford) VVV - Vacuum Vent Valve (Ford) W/B - Wheelbase WAC - WOT A/C Cutout Relay WACA - A/C WOT Cutout Relay Monitor WOT - Wide Open Throttle WOTV - Wide-Open Throttle Valve (Ford) WSS - Wheel Speed Sensor WU OC - Warm Up Oxidation Catalytic Converter WU TWC - Warm Up Three Way Catalytic Converter