Have any of the acronyms in your owner's manual ever made you shake your head? Do you get confused by some of the jargon that comes out of your mechanic's mouth? Don't worry, you're not alone. There's a lot of terminology to learn when you begin repairing and maintaining your vehicle, and at times it can seem daunting. This exhaustive list of automotive acronyms will help you cut through the jargon and improve your understanding.
AB - Air Bleed
ABDC - After bottom dead center
ABPV or ABV - Air Bypass Valve
AB - Air Bleed
ABDC - After bottom dead center
ABPV or ABV - Air Bypass Valve
ABS - Anti-lock Brake System
AC - Alternating current
A/C - Air Conditioner or Air Conditioning
ACCC - A/C Compressor Clutch
ACCCS - A/C Clutch Cycling Switch
ACL BI-Met - Air Cleaner Bimetal sensor
ACL DV - Air Cleaner Duct and Valve Vacuum motor
ACT - Air Charge Temperature sensor
ACV - Air Control Valve
ADS - Association of Diesel Specialists
AEA - Automotive Electric Association
AERA - Automotive Engine Rebuilders Association
A/F - Air/fuel
AFB - Aluminum four-barrel
AFC - Air-Flow Controlled
AFR - Air/fuel ratio
AFS - Air Flow Sensor
AI - Air Injection
AICV - Air Injection Check Valve
AIR-CHV - Air Check Valve
AIR-DV - Air Diverter Valve
AIR-IVV - Air Idle Vacuum Valve
AIS - Air Injection System
AIS - Automatic Idle Speed motor
AIV - Air Injection Valve
AMGV - Air Management Valve
AMS - Air Management System
ANTBV - Anti-Backfire valve
APDV - Air Pump Diverter Valve
API - American Petroleum Institute
AS - Airflow Sensor
ASE - Automotive Service Excellence
ASIA - Automotive Service Industry Association
ASME - American Society of Mechanical Engineers
ASRV - Air Switching Relief Valve
ASS - Air Switching Solenoid
ASV - Air Switching Valve
ATA - American Trucking Association
ATF - Automatic transmission fluid
ATS - Air Temperature Sensor
AWD - All-wheel-drive
BBDC - Before Bottom Dead Center
BCDD - Boost-Controlled Deceleration Device
BCI - Battery Council International
BDC - Bottom dead center
Bhp - Brake horsepower
BHS - Bi-Metal Heat Sensor
BMAP - Barometric and Manifold Absolute Pressure sensor
BP - Barometric Pressure sensor
BPA - By-Pass Air solenoid
BPEGR - Backpressure EGR
BPS - Barometric Pressure Sensor
BTU - British Thermal Unit
BV - Bowl Vent port
BVT - Backpressure Variable Transducer
C-3 - Computer Command Control system
C-4 - Computer Controlled Catalytic Converter system
CAM - Choke Air Modulator switch
CANP - Canister Purge solenoid
CAS - Cleaner Air System
CAT - Catalytic Converter
CAV - Coasting Air Valve
CBVV - Carburetor Bowl Vent Valve
CC - Catalytic Converter
CCC - Computer Command Control; Converter Clutch Control solenoid
CCEGR - Coolant Controlled Exhaust Gas Recirculation
CCEVS - Coolant Controlled Engine Vacuum Switch
CCIE - Coolant Controlled Idle Enrichment
CCO - Converter Clutch Override
CCS - Controlled Combustion System
CCT - Computer Controlled Timing
CCV - Closed Crankcase Ventilation system
CEC - Combined Emission Control system; Computerized Emission Control
system; Combination Emission Control
CES - Clutch Engine Switch
CID - Cubic Inch Displacement
CIS - Continuous Injection System
CKV - Check Valve
CLC - Converter Lock-up Clutch
CO - Carbon Monoxide
CO2 - Carbon Dioxide
COC - Conventional Oxidation Catalyst
CP - Crankshaft Position sensor
CPRV - Canister Purge Regulator Valve
CPS - Canister Purge Solenoid
CPV - Canister Purge Valve
CRV - Coasting Richener Valve
CSOV - Canister purge Shut Off Valve
CSSA - Cold Start Spark Advance system
CSSH - Cold Start Spark Hold system
CTAV - Cold Temperature Activated Vacuum
CTO - Coolant Temperature Override switch
CTS - Coolant Temperature Sensor; Coolant Temperature Switch
CTVS - Choke Thermal Vacuum Switch
CV - Check Valve
CWM - Cold Weather Modulator
DBC - Dual-Bed Catalytic Converter
DC - Direct current
DEFI - Digital Electronic Fuel Injection
DFS - Deceleration Fuel Shut-off
DIS - Distributorless Ignition System
DLV - Delay Valve
DP - Dashpot
DPDT - A double-pole, double-throw switch
DPST - A double-pole, single-throw switch
DRB II - Diagnostic Readout Box II
DS - Detonation Sensor See knock sensor
DSAV - Deceleration Spark Advance system
DV - Delay Valve
DVOM - Digital Volt-Ohmmeter
DVTRV - Diverter Valve
ECA - Electronic Control Assembly
ECC - Electronic Controlled Carburetor
ECM - Electronic Control Module
ECS - Evaporation Control System
ECT - Engine Coolant Temperature sensor
ECU - Electronic Control Unit
EDIS - Electronic Distributorless Ignition System
EDM - Electronic Distributor Modulator
EEC - Evaporative Emission Controls
EEC/EEC-I/EEC-II/EEC-III/EEC-IV - Electronic Engine Control systems
EEGR - Electronic EGR valve
EFC - Electronic Feedback Carburetor; Electronic Fuel Control
EFE - Early Fuel Evaporation
EFE TVS - EFE Thermal Vacuum Switch
EFI - Electronic Fuel Injection
EGO - Exhaust Gas Oxygen sensor
EGR-EPV - EGR External Pressure Valve
EGR-EVR - EGR Electronic Vacuum Regulator
EGR-FDLV - EGR Forward Delay Valve
EGR-RSR - EGR Reservoir
EGR-S/O - EGR Shut-Off
EGR-TVS - EGR Thermal Vacuum Switch
EGRV - EGR Vent solenoid
EGR-VCV - EGR Vacuum Control Valve
EGR-VSOL - EGR Vacuum Solenoid
EGR-VVA - EGR Venturi Vacuum Amplifier
EHCV - Exhaust Heat Control Valve
EIS - Electronic Ignition System
ELB - Electronic Lean Burn
EMF - Electromotive force, or voltage
EPA - Environmental Protection Agency
EPC - Electronic Pressure Control
EPR-SOL - Exhaust Pressure Regulator Solenoid
EPR-VLV - Exhaust Pressure Regulator Valve
ERS - Engine Rpm Sensor
ESC - Electronic Spark Control system
ESS - Engine Speed Sensor
ESSM - Engine Speed Switch Module
EST - Electronic Spark Timing system
ETC - Electronic Throttle Control
EVAP - Evaporative emission control system
EVCR - Emission Vacuum Control Regulator
EVP - EGR Valve Position sensor
EVR - EGR Vacuum Regulator
FAP - Forced Air Pre-heat system
FBC - Feedback Carburetor system
FBCA - Feedback Carburetor Actuator
FCS - Feedback Carburetor Solenoid, Feedback Control System, Fuel Control
Solenoid or Fuel Control System
FCV - Fuel Cut-off Valve
FI - Fuel Injection
FVEC - Fuel Vapor Emission Control
FVR - Fuel Vapor Recovery system
HAC - High altitude compensator
HAEC - High Altitude Emission Control system
HAI - Heated Air Inlet system
HC - Hydrocarbon
HCV - Heat control valve
HEGO - Heated EGO sensor
HEI - High Energy Ignition
HSC - High Swirl Combustion chamber
IAC - Idle Air Control
IAS - Inlet Air Solenoid valve
IAT - Intake Air Temperature
IBP - Integral Back Pressure
ICM - Ignition Control Module
ID - Inside diameter
IGN - Ignition
IHP - Indicated Horsepower
IMVC - Intake Manifold Vacuum Control
INJ - Injector
INJ GND - Injector Ground
ISS - Idle Stop Solenoid
ITC - Ignition Timing Control system
ITS - Idle Tracking Switch
IVV - Idle Vacuum Valve
JAS - Jet Air Stream
JCAV - Jet-Controlled Air Valve
JVS - Jet Valve System
KAM - Keep Alive Memory
KNK - Knock Sensor
KS - Knock Sensor
MAF - Mass Air Flow sensor
MAJC - Main Air Jet Control
MAT - Manifold Absolute Temperature sensor
MCS - Mixture Control System
MCT - Manifold Charge Temperature sensor
MCU - Microprocessor Control Unit
MEC - Motronic Engine Control
MECS - Mazda Equipped Control System
MEMA - Motor and Equipment Manufacturers Association
MEWA - Motor and Equipment Wholesalers Association
MFI - Mechanical Fuel Injection, or Multi-port Fuel Injection
MHCV - Manifold Heat Control Valve
MIL - Malfunction Indicator Light
MTA - Managed Thermactor Air
MVMA - Motor Vehicle Manufacturers Association
NADA - National Automobile Dealers Association
NAPA - National Automotive Parts Association
OC - Oxidation Catalyst
OHV - Overhead Valve
OS - Oxygen sensor
OSAC - Orifice Spark Advance Control
OSHA - Occupational Safety and Health Administration
OTVS - Oil Thermal Vacuum Switch
OXS - Oxygen Sensor system
PA - Pulse Air
PACV - Pulse Air Check Valve
PAF - Pulse Air Feeder
PAI - Pulse Air Injection
PAS - Pulse Air System
PCOV - Purge Control Valve
PCV - Positive Crankcase Ventilation system
PCVS - PCV Solenoid
PCVV - Positive Crankcase Ventilation Valve
PECV - Power Enrichment Control Valve
PFE - Pressure Feedback EGR sensor
PFI - Port Fuel Injection
PIP - Profile Ignition Pickup
PROM - Programmable Read-Only Memory
PSOV - Canister Purge Shut-Off Valve
PSPS - Power Steering Pressure Switch
PSV - Pulse Air Shut-off Valve
PTC - Positive Temperature Coefficient choke heater
PVA - Ported Vacuum Advance
PVCS - Ported Vacuum Control System
PVFFC - Pressure/Vacuum Fuel Filler Cap
PVS - Ported Vacuum Switch
RAM - Random Access Memory
RC - Rear Catalytic Converter
RDV - Retard Delay Valve or Reverse Delay Valve
RMA - The Rubber Manufacturers Association
ROM - Read Only Memory
SAS - Secondary Air Supply system See “Air Injection System.”
SBC - Single Bed Catalytic converter
SCC - Spark Control Computer
SCS - Spark Control System, or Speed Controlled Spark
SCVAC - Speed Control Vacuum Control
SDV - Spark Delay Valve
SEC ACT - Secondary Actuator
SEFI - Sequential Electronic Fuel Injection
SFI - Sequential Fuel Injection See “Sequential Electronic Fuel Injection.”
SHED - Sealed Housing Evaporative Determination system
SIL - Shift Indicator Light
SIS - Solenoid Idle Stop
SOL V - EGR Solenoid Vacuum Valve Assembly
SPFI - Single-Point Fuel Injection
SPDT - A single-pole, double-throw switch
SPST - A single-pole, single-throw switch
SRS - Supplemental Restraint System (airbag)
SSI - Solid State Ignition system
SVCBV - Solenoid Valve Carburetor Bowl Vent
SVV - Solenoid Vent Valve
TAC - Thermostatically Controlled Air cleaner
TCS - Transmission Controlled Spark
TDC - Top dead center
TAD - Thermactor Air Diverter solenoid
TAV - Temperature Activated Vacuum system
TC - Throttle Closer
TCAC - Thermostatic Controlled Air Cleaner system
TCC - Transaxle Converter Clutch system
TCS - Throttle Control System, or Transmission Controlled Spark system or
Transmission Converter Switch
TDC - Top Dead Center
TDP - Throttle closing Dashpot
TDS - Time Delay Solenoid
TEC - Thermactor Exhaust Control system
TES - Thermal Electric Switch
TFI, TFI-IV - Thick Film Integrated Ignition (Ford systems)
TIC - Thermal Ignition Control
TIV - Thermactor Idle Vacuum valve
TK - Throttle Kicker vacuum solenoid valve
TKA - Throttle Kicker Actuator
TKS - Throttle Kicker Solenoid
TO - Thermal Override
TOC - Throttle Opener Control system
TP - Throttle Position, or Throttle Position Sensor
TPI - Tuned Port Injection
TPS - Throttle Position Sensor
TR - Thermal Reactor
TSD - Throttle Solenoid
TSP - Throttle Solenoid Positioner
TVS - Temperature Vacuum Switch or Thermal Vacuum Switch
TVSV - Thermostatic Vacuum Switch Valve
TVV - Thermal Vacuum Valve, or Thermal Vent Valve
TWC - Three-Way Catalyst
UBC - Underbody Catalyst
VAC - Vacuum Advance Control
VAF - Vane Air Flow meter
VAT - Vane Air Temperature sensor
VAV - Vacuum Advance Valve
VB - Vacuum Break
VBV - Vacuum Bias valve
VCKV - Vacuum Check Valve
VCS - Vapor Control System, or Vacuum Control Switch
VCV - Vacuum Control Valve
VDV - Vacuum Delay Valve or Vacuum Differential Valve
VECI - Vehicle Emission Control Information decal
VHC - Vacuum Operated exhaust Heat Control valve
VIN - Vehicle Identification Number
VMV - Vacuum Modulator Valve
VOC - Volatile organic compounds
VOM - Volt-Ohmmeter
VOTM - Vacuum-Operated Throttle Modulator
VP - Vacuum Pump
VRDV - Vacuum Retard Delay Valve
VRESER - Vacuum Reservoir
VREST - Vacuum Restrictor
VR or VRS - Variable Reluctance Sensor
VR/S - Vacuum Regulator Solenoid
V-RSR - Vacuum reservoir
V-RST - Vacuum restrictor
VRDV - Vacuum Retard Delay Valve
VRES - Vacuum Reservoir
VREST - Vacuum Restrictor
VRV - Vacuum Reducer Valve, or Vacuum Regulator Valve
VS - Vacuum Switch
VSA - Vacuum Switch Assembly
VSC - Vehicle Speed Control sensor
VSS - Vehicle Speed Sensor, or Vacuum Switch Solenoid
VSV - Vacuum Solenoid Valve, or Vacuum Switching Valve
VTM - Vacuum Throttle Modulator
VTP - Vacuum Throttle Positioner
VTV - Vacuum Transmitting Valve
VVA - Venturi Vacuum Amplifier
VVC - Variable Voltage Choke
VVV - Vacuum Vent Valve
WAC - Wide-open throttle Air conditioner Cutoff
WOT (wide open throttle)
WOTS - Wide-Open Throttle Switch
WOTV - Wide Open Throttle Valve
