Automotive Definitions and Acronyms
The automotive industry loves abbreviations and acronyms. Take for instance this conversation recently overheard, "Your MAF has failed and the ECM is setting a DTC."
What the ...?
Well, this is why we created this list, to help decipher what all these things mean. Next to each acronym you will find a brief description, and we will link to additional information as it becomes available.
| Acronym | Definition | | A/C | Air Conditioning | | A/F | Air/Fuel Ratio | | A/T | Automatic Transmission or Transaxle | | ABS | Anti-Lock Brake System | | AC | Alternating Current | | AIR | Secondary Air Injection | | ATDC | After Top Dead Center | | ATF | Automatic Transmission Fluid | | AWD | All-Wheel Drive | | B1 | Bank 1 | | B1 S1 | Bank 1 Sensor 1 | | B1 S2 | Bank 1 Sensor 2 | | B2 | Bank 2 | | B2 S1 | Bank 2 Sensor 1 | | B2 S2 | Bank 2 Sensor 2 | | B+ | Battery Positive Voltage (12 Volts) | | BMW | Bayerische Motoren Werke (Bavarian Motor Works) | | BARO | Barometric Pressure (Atmospheric Pressure) | | BAT | Battery | | BCM | Body Control Module | | BHP | Brake Horsepower | | BTC | Before Top Center | | BTDC | Before Top Dead Center | | BTU | British Thermal Units | | C | Celsius | | CAC | Charge Air Cooler (Inter-Cooler) | | CC | Cubic Centimeters | | CFI | Continuous Fuel Injection | | CFM | Cubic Feet per Minute | | CID | Cubic Inch Displacement | | CIS | Continuous Injection System | | CIS-E | Electronic Continuous Injection System | | CKP | Crankshaft Position Sensor | | CL | Closed Loop | | CMP | Camshaft Position Sensor | | CO | Carbon Monoxide | | CO2 | Carbon Dioxide | | CPP | Clutch Pedal Position | | CTP | Closed Throttle Position | | dB | Decibels | | DC | Direct Current | | DFI | Direct Fuel Injection | | DLC | Data Link Connector | | DOHC | Dual Overhead Cams | | DTC | Diagnostic Trouble Code | | DTM | Diagnostic Test Mode | | DVOM | Digital Volt Ohm Meter | | EBCM | Electronic Brake Control Module | | EBTCM | Electronic Brake Traction Control Module | | EC | Engine Control | | ECM | Engine Control Module | | ECT | Engine Coolant Temperature | | EFE | Early Fuel Evaporation | | EGR | Exhaust Gas Recirculation | | EGRT | EGR Temperature | | EI | Electronic Ignition | | EM | Engine Modification | | EMI | Electromagnetic Interference | | EPROM | Erasable PROM | | EVAP | Evaporative Emission System | | F | Fahrenheit | | FC | Fan Control | | FF | Flexible Fuel | | FP | Fuel Pump | | FPROM | Flash Erasable PROM | | FT | Fuel Trim (Fuel Mixture) | | ft. lb. | Foot Pound (Unit of Measure for Torque) | | FTP | Federal Test Procedure | | FWD | Front-Wheel Drive | | gal | Gallon | | GEN | Generator | | GND | Ground | | GPM | Grams per Mile | | H20 | Water | | HC | Hydrocarbon | | Hg | Mercury (Unit of Measure for Vacuum) | | HO2S | Heated Oxygen Sensor | | HO2S1 | Upstream Heated Oxygen Sensor | | HO2S2 | Up or Downstream Heated Oxygen Sensor | | HO2S3 | Downstream Heated Oxygen Sensor | | HP | Horsepower | | HVAC | Heating Ventilation and A/C System | | HVS | High Voltage Switch | | I/M | Inspection/Maintenance | | I/P | Instrument Panel | | IA | Intake Air | | IAC | Idle Air Control | | IAT | Intake Air Temperature | | IC | Ignition Control Circuit | | ICM | Ignition Control Module | | ID | Inside Diameter | | IFS | Inertia Fuel Shutoff | | IGN | Ignition | | IPC | Instrument Panel Cluster | | ISC | Idle Speed Control | | kHz | Kilohertz | | Km | Kilometers | | KOEC | Key On, Engine Cranking | | KOEO | Key On, Engine Off | | KOER | Key On, Engine Running | | kPa | Kilopascals | | KS | Knock Sensor | | KV | Kilovolts | | L | Liters | | lb. ft. | Pound Feet | | LT | Long Term Fuel Trim | | MAF | Mass Airflow Sensor | | MAP | Manifold Absolute Pressure Sensor | | MC | Mixture Control | | MFI | Multiport Fuel Injection | | MIL | Malfunction Indicator Lamp | | mm | Millimeters | | MPG | Miles per Gallon | | MPH | Miles per Hour | | ms | Millisecond (1/1000 of a Second) | | mV | Millivolts | | Nm | Newton Meters | | NOX | Oxides of Nitrogen | | O2S | Oxygen Sensor | | OBD | Onboard Diagnostics | | OBD I | Onboard Diagnostics, First Generation | | OBD II | Onboard Diagnostics, Second Generation | | OC | Oxidation Catalyst | | OD | Outside Diameter | | ODM | Output Device Monitor | | OE | Original Equipment | | OEM | Original Equipment Manufacturer | | OHC | Overhead Cam | | OL | Open Loop | | P/B | Power Brakes | | P/N | Part Number | | P/S | Power Steering | | PAIR | Pulsed Secondary Air Injection | | PCM | Powertrain Control Module | | PCV | Positive Crankcase Ventilation | | PNP | Park/Neutral Switch | | PPM | Parts per Million | | PROM | Programmable Read Only Memory | | PSA | Pressure Switch Assembly | | PSI | Pounds per Square Inch | | PSP | Power Steering Pressure | | pt. | Pint | | Qt. | Quart | | RAM | Random Access Memory | | RFI | Radio Frequency Interference | | ROM | Read Only Memory | | RPM | Revolutions per Minute | | RWD | Rear-Wheel Drive | | SC | Supercharger | | SCB | Supercharger Bypass | | SFI | Sequential Fuel Injection | | SOHC | Single Overhead Cam | | SRI | Service Reminder Indicator | | SRT | System Readiness Test | | ST | Short Term Fuel Trim | | TACH | Tachometer | | TB | Throttle Body | | TBI | Throttle Body Injection | | TC | Turbocharger | | TCC | Torque Converter Clutch | | TCCM | Transfer Case Control Module | | TCM | Transmission or Transaxle Control Module | | TDC | Top Dead Center | | TFP | Throttle Fluid Pressure | | TP | Throttle Position | | TPS | Throttle Position Sensor | | TVV | Thermal Vacuum Valve | | TWC | Three Way Catalyst | | TWC+OC | Three Way + Oxidation Catalytic Converter | | V | Volts | | VATS | Vehicle Anti-Theft System | | VAC | Volts Alternating Current | | VAF | Volume Airflow | | VDC | Volts Direct Current | | VIN | Vehicle Identification Number | | VR | Voltage Regulator | | VS | Vehicle Sensor | | VSS | Vehicle Speed Sensor | | WOT | Wide Open Throttle | | WU-TWC | Warm Up Three-Way Catalytic Converter | | | |