Check Engine Light Related Acronyms
Below is our most current list of acronyms related to automotive check engine lights.
As time goes on we will be adding more on general repair, and some relating to other areas such as anti-lock brakes, air bag systems and more.
Please let us know if you need additional acronym information, and we will post it as quickly as possible. Thank you.
Check Engine Light Acronyms A - D
AIR : Secondary Air Injection
BARO: Barometric Pressure
BPP: Brake Pedal Position
BPS: Brake Pedal Switch
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.
CAN: Controller Area Network
CCM: Comprehensive Component Monitor
CHT: Cylinder Head Temperature
CKP: Crankshaft Position
CMCV: Charge Motion Control Valve
CMP: Camshaft Position
COP: Coil On Plug. Ignition coil on plug assembly
CPP: Clutch Pedal Position
CPU: Central Processing Unit
CV: Canister Vent Solenoid. A solenoid which seals the evaporative emission (EVAP) system from the atmosphere during EVAP monitor test.
DLC: Data Link Connector. SAE standard J1962 connector providing access to vehicle diagnostic information.
DMM: Digital Multimeter
DTC: Diagnostic Trouble Code. An alpha/numeric identifier for a concern identified by the OBD system.
Check Engine Light Acronyms E - H
ECM: Electronic Control Module
ECT: Engine Coolant Temperature
EEC: Electronic Engine Control
EEGR: Electric Exhaust Gas Recirculation 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.
EI: Electronic Ignition. An electronic ignition system that has the ignition control module integrated into the PCM.
EMI: Electromagnetic Interference. Usually caused by ignition voltage spikes, solenoids, relay operation, or noisy generator contacts.
EOT: Engine Oil Temperature
ERFS: Electronic Returnless Fuel System
ESM: EGR System Module
ESOF: Electronic Shift-on-the-Fly
ETB: Electronic Throttle Body
ETBTPS: Electronic Throttle Body Throttle Position Sensor
ETC: Electronic Throttle Control
EVAPCP: Evaporative Canister Purge Valve. A valve which controls the venting of fuel vapor from the evaporative emissions canister into the intake manifold for combustion.
FCIL: Fuel Cap Indicator Lamp. Indicates that the fuel filler cap is not correctly installed.
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.
FMEM: Failure Mode Effects Management. Operating strategy that maintains limited vehicle function in the event of a PCM or EEC component failure.
FPDM: Fuel Pump Driver Module. A module that controls the electric fuel pump.
FPM: Fuel Pump Monitor
FRP: Fuel Rail Pressure
FTP: Fuel Tank Pressure
HO2S: Heated Oxygen Sensor. Provides information on rich or lean exhaust conditions to the PCM.
Check Engine Light Acronyms I - L
IAC: Idle Air Control. Electrical control of throttle bypass air.
IAT: Intake Air Temperature
IDM: Ignition Diagnostic Monitor
IFS: Inertia Fuel Shut-Off
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.
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. A dedicated and un-switched power circuit that maintains KAM.
KOEO Self-Test: Key On Engine Off Self-Test. A test of the EEC system conducted by the PCM with power applied and the engine at rest.
KOER Self-Test: 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.
KS: Knock Sensor
LONGFT: Long-Term Fuel Trim. Fuel flow adjustment determined by the PCM.
Check Engine Light Acronyms M - P
MAF: Mass Air Flow
MAP: Manifold Absolute Pressure. The internal pressure of the intake manifold.
MIL: Malfunction Indicator Lamp. An indicator lamp alerting the driver of an EEC related concern. Also referred to as the Check Engine Light.
MRFS: Mechanical Returnless Fuel System
OHC: Overhead Cam. An engine configuration that uses a single camshaft positioned above the valves.
OL: Open Loop. An operating condition based on instructions not modified by PCM feedback.
PCM: Power train Control Module. Formerly know as the electronic engine control (EEC) processor.
PCV: Positive Crankcase Ventilation. A system which allows the controlled flow of crankcase vapors into the combustion chamber.
PID: Parameter Identifier. Identifies an address in the PCM memory which contains operating information. Helpful with check engine light diagnosis.
PIP: Profile Ignition Pickup. Provides crankshaft position information for ignition synchronization.
PSP: Power Steering Pressure. Indicates the pressure in the power steering system.
PWM: Pulse Width Modulation. Controls the intensity of an output by varying the signal duty cycle.
PWR GND: Power Ground. The main ground circuit in the EEC system.
Check Engine Light Acronyms Q - T
RAM: Random Access Memory. Memory into which information can be written as well as read.
ROM: Read-Only Memory. Computer memory that can be accessed and used, but not altered.
RPM: Revolutions Per Minute
SAE: Society of Automotive Engineers
SFI: Sequential Multiport Fuel Injection. A multiport fuel delivery system in which each injector is individually energized and timed relative to its cylinder intake event.
SHRTFT: Short-Term Fuel Trim. Fuel flow adjustment in response to the Oxygen sensors input during closed-loop operation.
SIG RTN: Signal Return. A dedicated sensor ground circuit that is common to 2 or more sensors.
TCM: Transmission Control Module
TDC: Top Dead Center
TP: Throttle Position
TSB: Technical Service Bulletin. Notifies technicians of any known vehicle concerns, procedures or general repair information.
Check Engine Light Acronyms V - Z
VCT: Variable Camshaft Timing
VECI: Vehicle Emission Control information
VIN: Vehicle Identification Number. A unique identification number given to every vehicle produced. Includes information about the year, model, engine and plant origin of the vehicle.
VMV: Vapor Management Valve.
VPWR: Vehicle Power. A switched circuit that provides power to the EEC system. Compare to battery voltage (B+)
VREF: Reference Voltage. A dedicated circuit that provides an approximate 5.0 volt signal used as a reference by certain sensors.
VRIS: Variable Resonance Induction System
WOT: Wide Open Throttle. A condition of maximum airflow through the throttle body.
Transmission Related Check Engine Light Acronyms
A/T: Automatic Transmission
CCS: Coast Clutch Solenoid
EPC: Electronic Pressure Control
ISS: Intermediate/Input Shaft Speed Sensor
OCS: Overdrive Cancel Switch
OSS: Output Shaft Speed. Indicates the rotational speed of the transmission output shaft.
PNP: Park/Neutral Position switch
SSA/SSB/SSC/SSD/SSE: Shift solenoids. Devices in an automatic transmission that control the shifting by varying fluid flow when commanded by the PCM.
TCC/TCCH: Torque Converter Clutch. When energized, causes a mechanical engagement and disengagement of the torque converter clutch.
TCIL: Transmission Control Indicator Lamp. Indicates that the TCS has been activated.
TCS: Transmission Control Switch. Modifies the operation of electronically controlled transmissions.
TFT: Transmission Fluid Temperature. Indicates the temperature of transmission fluid.
TR: Transmission Range. The range in which the transmission is operating.
TSS: Turbine Shaft Speed. Indicates the rotational speed of the transmission turbine shaft.
VSS: Vehicle Speed Sensor. A magnetic pickup device that generates an AC signal that is proportional to the vehicle speed.