Acronyms and Definitions

4V:  Four valves per engine cylinder

ABS:  Anti-Lock Brake System

ABS_STAT:  ABS system status TCM received PID

A/C:  Air Conditioning

A/CC:  Air Conditioning Clutch

A/CCR:  A/C Clutch Control Relay

A/CLPCS:  A/C Low Pressure Cycling Switch

ACCS:  Air Conditioning Cycling Switch

ACD:  Air Conditioning Demand. A signal input to the PCM from the air conditioning control panel.

ACDS:  Air Conditioning Diagnostic Switch (refrigerant containment switch)

ACET:  Air Conditioning Evaporator Temperature (may also be referred to as Evaporator Air Discharge Temperature)

ACFDS_B:  Air Conditioning Full Demand Switch (for traction battery compartment)

ACFDS_P:  Air Conditioning Full Demand Switch (for passenger compartment)

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

ACPSW:  Air Conditioning Pressure Switch

ACPT:  Air Conditioning Pressure Transducer (switch)

ACP V:  Air Conditioning Pressure Volts. A voltage input to the PCM from the ACP switch or sensor.

ACRDV:  A/C Refrigerant Distribution Valve Output

ACRDV_F:  A/C Refrigerant Distribution Valve Output Fault

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

ADC:  See ATDC.

Air/Fuel Ratio:  Air-to-fuel mixture ratio. An air-to-fuel mixture that is 14.7:1 is also called stoichiometry.

Ambient Air Temperature:  Temperature of the air surrounding an object

Analog (Electrical/Electronic):  An electrical signal that can obtain any value within the voltage limits of the signal.

APP, APP1, APP2, APP3:  Accelerator Pedal Position 1, 2, 3

APPS, APPS1, APPS2, APPS3:  Accelerator Pedal Position Sensor 1, 2, 3

ARB:  Air Resource Board

ARPMDES:  Desired engine speed TCM received PID

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

Base Timing:  Spark advance in degrees before top dead center of the base engine without any control from the PCM.

Battery Positive Voltage (B+):  The positive (+) voltage from the battery or any circuit connected directly to the battery.

BATTEMP:  Battery Temperature

BJB:  Battery Junction Box

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

BPA:  Brake Pedal Applied. Typically located on the braking system master cylinder. Can be hydraulic or electric.

BPO:  Battery Power Off

BPO_Hz:  Battery Power Off Frequency PID

BPP:  Brake Pedal Position

BPS:  Brake Pedal Switch/Speed Control Deactivation

BRAKE_LMP or BRKL:  Brake Warning Lamp Status. Activates the brake warning lamp by applying voltage to the control line.

BSI:  Brake Shift Interlock

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.

Bus + or Bus -:  Multiplex circuits that carry controller area network (CAN) data from module to module and to the data link connector (DLC).

BVREF:  Buffer Voltage Reference. A dedicated circuit that provides approximately a 5 volt signal used as a reference by certain sensors.

CAFE:  Corporate Average Fuel Economy. A set of federal requirements and regulations which govern fuel economy standards.

CANVNT:  Canister Vent

CAN:  Controller Area Network

Catalyst:  Catalytic converter. An in-line exhaust system device used to reduce the level of engine exhaust emissions.

CAT EVAL:  Catalyst System Evaluated. This item indicates YES when the catalyst efficiency monitor has successfully completed.

CCM:  Comprehensive Component Monitor

CCNT:  Number of Stored and Pending DTCs

CD A through D:  Coil Driver 1 through 4

Centralized Testing Facility:  State government operation. Provides inspection/maintenance (IM) and safety inspections.

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

CHT:  Cylinder Head Temperature. Units are displayed in either degrees Fahrenheit or Celsius.

CHTV:  Cylinder Head Temperature Voltage

CKP:  Crankshaft Position

CKP_SHLD:  Crankshaft Position Shield

CKP+, CKP-:  CKP+ is the crankshaft position (CKP) sensor signal wire. CKP- is the signal return.

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

CMP:  Camshaft Position. PCM input signal from the camshaft position sensor.

CMPFM:  Camshaft Position Failure Mode. Indicates when the PCM identifies a CMP concern.

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.

CO  ₂  :  Carbon Dioxide. A colorless, odorless gas that is a normal by-product of the combustion of fuel.

Coil:  A device consisting of windings around an iron core. In a spark ignition system, designed to increase voltage.

Cold Soak:  Time given to a vehicle to sit at a low temperature, typically below 20°C (68°F), until the temperature of external and internal components stabilizes.

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

CONTACT:  Traction battery contactor status TCM received PID

Continuous Memory Self-Test:  A continuous test of the EEC system conducted by the PCM whenever the vehicle is operating.

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

CRK_T:  Time since engine started PID

CSE GND:  Case Ground

CT:  Closed Throttle. A mode when 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

DC:  1. Direct Current. Electric current flowing in 1 direction. 2. Duty Cycle. The voltage measurement of ON time versus the full cycle period, expressed in percent.

DCE:  DC/DC Converter Enable

DCE_F:  DC/DC Converter Enable Fault

DCF:  DC/DC Converter Fault

DCL:  Data Communication Link. A communication path between various in-vehicle electronic modules. Accessed by diagnostic tools through the data link connector (DLC).

Digital:  Controls process information by switching the current or voltage ON and OFF.

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

DLC:  Data Link Connector. 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.

DRI:  Deposit Resistant Injector. A fuel injector designed to prevent the build-up of carbon and other unwanted deposits.

DRIVECT:  Number of completed OBD Drive Cycles PID

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.

ECT:  Engine Coolant Temperature. Displayed in either Fahrenheit or Celsius.

ECTV:  Electronically Controlled Continuously Variable Transaxle

EEC:  Electronic Engine Control

EEC-V:  Fifth-generation EEC system

EEPROM:  Electrically Erasable Programmable Read Only Memory

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

EGR EVAL:  Exhaust Gas Recirculation System Evaluated. EGR EVAL will display YES when the monitor is complete.

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

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

EGRMDSD:  Electric Exhaust Gas Recirculation Motor Desired Position. The PID name used to operate the EEGR valve with diagnostic tools output state control.

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

EI:  Integrated Electronic Ignition. An electronic ignition system that has the ignition control module (ICM) integrated into the PCM.

EI-LDR:  Electronic Ignition-Low Data Rate

ENG CTO:  Vehicle speed TCM received PID

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.

EOT:  Engine Oil Temperature

EPA:  Environmental Protection Agency (United States Government)

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

ESM:  EGR System Module

ETC:  Electronic Throttle Control

ETCVREF:  Voltage Reference (5V) for ETC (APP BVREF, TP BVREF)

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

EVAPCP:  Evaporative Canister Purge Solenoid. Controls a solenoid which allows venting of the evaporative purge canister.

EVAPCPF:  Evaporative Canister Purge Solenoid Fault. Identifies whether an electrical concern exists for the current commanded state.

EVAPCV:  Evaporative Canister Vent Solenoid. Controls a solenoid which seals the EVAP system canister from atmospheric pressure during the EVAP OBD Monitor test.

EVAPCVF:  Evaporative Canister Vent Solenoid Fault.

Evaporative Emissions Canister:  An evaporative emission canister containing activated charcoal which absorbs and holds fuel vapors.

EVAPPDC:  Evaporative Canister Purge Duty Cycle. The duty cycle commanded to the EVAP canister purge solenoid by the PCM.

EVAPVMA:  Evaporative Vapor Management Valve Internal Circuit Monitor

EVO:  Electronic Variable Orifice

EVMV:  Electric Vapor Management Valve. Also known as the EVAP canister purge valve.

Exciter Ring:  A toothed or notched iron or steel disk which is the moveable part of a speed sensor.

FAN:  Fan Speed

FC, FC1, FC2, FC3:  Fan Control

FCS:  Fuel Control Solenoid

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

FEAD:  Front End Accessory Drive

FEPS:  Flash EEPROM Programming Signal. 18-volt DC signal sent by the diagnostic tool to initiate PCM reprogramming.

FLI:  Fuel Level Input. Used by the EVAP monitor to calculate fuel tank vapor volume. Displayed as a percentage.

FLI V:  Fuel Level Input Voltage

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.

FPC:  Fuel Pump Control

FPDM:  Fuel Pump Driver Module. A module that controls the electric fuel pump.

FPF:  Fuel Pump Fault. Identifies whether a concern exists in the FP circuit.

FPM:  Fuel Pump Monitor. Monitors the fuel pump/circuits for concerns.

Freeze Frame:  A block of memory containing the vehicle operating conditions at a specific time.

FRP:  Fuel Rail Pressure

FRPT:  Fuel Rail Pressure Temperature Sensor

FRP V:  Fuel Rail Pressure Voltage. A voltage input to the PCM from the fuel rail pressure sensor.

FRT:  Fuel Rail Temperature

FRT_V:  Fuel Rail Temperature Voltage

FRTMPAB:  Engine Fuel Temperature-Bank 1 Input

FSC:  Fail-Safe Cooling

FTIV:  Fuel Tank Isolation Valve

FTP:  Fuel Tank Pressure

FTP V:  Fuel Tank Pressure Voltage. From the FTP transducer

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 time of last data update.

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

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

Fuel Tank Vapor Valve:  A valve mounted in the top of the fuel tank that vents excess vapor and pressure from the fuel tank into the evaporative emission control system.

FWD:  Front Wheel Drive

GCLTEMP:  Generator Motor Coil Temperature

GCU:  Generator Control Unit

GENMODE:  Generator Motor operational mode TCM received PID

GND:  Ground

GPM:  Grams per Mile. Also known as Gallons per Minute.

Green State Vehicle:  Formally known as California Emissions. A vehicle that is equipped with California onboard diagnostics.

GSDN:  Generator Motor Shutdown

G_SDN:  Generator Motor Shutdown Request PCM PID

G_SDN_A, G_SDN_C:  Generator Motor Shutdown Request TCM PIDs

G_SPEED:  Generator Motor Speed

GTQ_CMD:  Measured generator motor torque PID

GTQ_OUT:  Desired generator motor torque TCM received PID

G_INV_V:  Actual generator motor inverter voltage

G_PHTEMP:  Highest of 3 phases generator motor inverter temperature

GVW:  Gross Vehicle Weight

Hall Effect:  A process where current is passed through a small portion of semiconductor material and a magnetic field to produce a small voltage in the semiconductor.

Hard Fault:  A concern currently present in the system

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

HFC:  High Fan Control

HFCF:  High Fan Control Fault. Identifies if there is a concern in the HFC circuit.

HFPIP:  PIP up edge to PIP down edge time

High Speed CAN:  High Speed Controller Area Network

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

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

Hot Soak:  Period of time after an engine operates where localized combustion heat dissipates throughout the engine.

HPUMP:  Heater Pump Control

HPUMP_F:  Heater Pump Fault

HTR, HTR11, HTR12:  HO2S Heater. Heater element for the HO2S sensor.

HTR11F, HTR12F:  HO2S Heater Fault

HV_AMP:  Traction battery current TCM received through the communication network PID.

HVBAT_V:  Traction battery voltage TCM received through the communication network PID.

HVIL:  High Voltage Interlock Circuit

HVINTLCK:  High Voltage Interlock Circuit Status PID

HVIN:  High Voltage Interlock Negative Circuit

HVIP:  High Voltage Interlock Positive Circuit

HVN:  High Voltage Negative Circuit

HVP:  High Voltage Positive Circuit

Hydrogen:  Chemical symbol H. Highly flammable gas.

Hz:  Hertz. Cycles per second

IAT:  Intake Air Temperature

IAT_V:  Intake Air Temperature Voltage. Actual voltage drop across the IAT sensor.

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

IFS:  Inertia Fuel Shut Off

IGN GND:  Ignition Ground

Ignition:  System used to provide high voltage spark for engines

IGN_KEY:  Ignition Key

IGN_OFF:  Ignition Switch Position OFF Input PID

IGN_R:  Ignition Switch Position RUN Input PID

IGN_R/S:  Ignition Switch Position START Input PID

IGN_SW:  Ignition Switch Position

IMAP:  Inferred MAP

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

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

INJ1, INJ2, INJ3, INJ4:  Injector number or its signal output from the PCM.

INJ_TIM:  Injector Timing Before Top Dead Center

Injector:  A device for delivering metered pressurized fuel to the intake system or the cylinders.

Intake Air:  Air drawn through a filter and distributed to each cylinder for use in combustion.

IPC:  Independent Plausibility Checker

ISDN1, ISDN2:  Immediate Shutdown Circuits 1 and 2

I_SDN_1, I_SDN_2:  Immediate Shutdown 1 and 2 PIDs

ISP-R:  Ignition Switch Position RUN Circuit

ISP-R/S:  Ignition Switch Position START Circuit

ISO:  International Standards Organization

ITCC:  Intelligent Torque Controlled Coupling

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 unswitched power circuit that maintains KAM.

KEYPWR:  Key Power. Battery voltage supplied when the ignition key is in the ON position.

Knock:  A sharp metallic sound produced when 2 combustion pressure fronts collide in the combustion chamber of an engine.

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.

Km/h:  Kilometers Per Hour

kPa:  Kilopascal. Unit of pressure. 3.386 kPa equals 1 inch of mercury (Hg.)

KS1:  Knock Sensor Bank 1. Detects engine knock.

L:  Liters. The unit of volume in the metric measuring system. One liter equals 1.06 quarts.

LDR:  Low Data Rate. Type of misfire monitor.

LFC:  Low Fan Control

LFCF:  Low Fan Control Fault

LOAD:  Calculated Engine Load

LONGFT1:  Long-Term Fuel Trim Bank 1. Fuel flow adjustment determined by the PCM.

LOOP:  Indicates OPEN or CLOSED loop status.

LOS:  Limited Operating Strategy

LOSSTRT:  Limited Operating Strategy related to the engine no start condition

LOS_BRK:  Limited Operating Strategy related to regenerative braking concern

LOS_ENG:  Limited Operating Strategy related to the engine concern

LOS_ETC:  Limited Operating Strategy related to the ETC system concern

LOS_EQ:  Limited Operating Strategy related to the E-Quizzer detected concern

LOS_GEN:  Limited Operating Strategy related to the generator motor concern

LOS_HV:  Limited Operating Strategy related to the high voltage traction battery concern

LOS_IPC:  Limited Operating Strategy related to the independent plausibility checker detected concern

LOS_KEY:  Limited Operating Strategy related to the ignition key position concern

LOS_LV:  Limited Operating Strategy related to the low voltage system concern

LOS_MOT:  Limited Operating Strategy related to the traction motor concern

LOS_TCM:  Limited Operating Strategy related to the transaxle concern

LPLR:  Low Pressure Low Resistance fuel injector

MAF:  Mass Air Flow

MAF_V:  Mass Air Flow Voltage

MAF RTN:  Mass Air Flow Return. A return circuit for the MAF sensor.

MAP:  Manifold Absolute Pressure. The internal pressure of the intake manifold.

MAP_V:  Manifold Absolute Pressure Voltage

MCLTEMP:  Traction Motor Coil Temperature

MCU:  Motor Control Unit

MECT:  Motor Electronics Cooling Temperature

MECT_V:  Motor Electronics Cooling Temperature Voltage

MECP:  Motor Electronics Cooling Pump Control

MECP_F:  Motor Electronics Cooling Pump Fault

MECP_V:  Motor Electronics Cooling Pump Voltage

MFC:  Medium Fan Control

Microprocessor:  A device that controls logic and arithmetic functions.

MIL:  Malfunction Indicator Lamp. An indicator lamp alerting the driver of an emission related malfunction.

MISF:  Misfire. Any event in the cylinder that causes a sudden change in acceleration of the crankshaft.

MSDN:  Motor Shutdown

M_SDN:  Motor Shutdown Request PCM PID

M_SDN_A, M_SDN_C:  Traction motor shutdown request TCM PIDs

MTQ_CMD:  Measured traction motor torque PID

MTQ_OUT:  Desired traction motor torque TCM received PID

M_INV_V:  Actual traction motor inverter voltage

M_PHTEMP:  Highest of 3 phases traction motor inverter temperature

M_SPEED:  Traction Motor Speed

MY:  Model Year

NC:  Normally Closed

NGS:  New Generation Self-Test Automatic Readout (STAR) tester.

NO:  Normally Open

NO  _X  :  Oxides of Nitrogen. Formed at high combustion temperatures.

O2S, O2S11, O2S12:  Oxygen Sensor. Provides information on rich or lean exhaust conditions to the PCM.

O2S11SV, O2S12SV:  Oxygen Sensor Voltage Input Pids.

OASIS:  On-line Automotive Service Information System

OBD, OBD-II:  On-Board Diagnostics, On-Board Diagnostics Second Generation. A system that monitors PCM input and output control signals.

On-Demand Test:  The KOEO and KOER tests of the PCM and KOEO test of the TCM initialized by a technician.

OC:  Oxidation Catalytic converter. A catalytic converter system that reduces the levels of HC and CO emissions.

OCT ADJ:  Octane Adjust. Compensating strategy that adjusts for changes in fuel octane.

OEM:  Original Equipment Manufacturer

OHC:  Overhead Cam. An engine configuration that uses a single camshaft positioned above the valves.

Open Circuit:  A circuit which does not provide a complete path for flow of current.

OL:  Open Loop. An operating condition based on instructions not modified by PCM feedback.

OSC:  Output State Control

OTM:  Output Test Mode

Ozone:  A blue gaseous form of oxygen (O ₃ ) formed naturally by electric discharge or exposure to ultraviolet radiation.

PCM:  Powertrain Control Module

PCV:  Positive Crankcase Ventilation. A system which allows the controlled flow of crankcase vapors into the combustion chamber.

PF:  Purge Flow. Amount of fuel vapor burned in the engine.

Photochemical:  Term describing the action of light on air pollutants which results in creating smog.

PID:  Parameter Identifier. Identifies an address in PCM memory which contains operating information.

PIP:  Profile Ignition Pickup. Provides crankshaft position information for ignition synchronization.

PIP_CTR:  PIP counter

PIPTIM:  Last PIP time

Potentiometer:  An adjustable resistance component commonly used as a sensor (example: TP sensor).

Powertrain:  Engine and transmission/transaxle components.

Pressure - Absolute:  A pressure referenced to a perfect vacuum.

Pressure - Atmospheric:  The pressure of the surrounding air at any given temperature and altitude. Sometimes called barometric pressure.

Pressure - Barometric:  Atmospheric pressure or the results obtained by a barometer.

Pressure - Differential:  The pressure difference between 2 regions, such as between the intake manifold and the atmospheric pressure.

Pressure - Gauge:  The amount by which the absolute pressure exceeds the atmospheric pressure.

PRNDL:  Gear Selector Position

PRNDL_T:  Gear Selector position TCM received PID

PPM:  Parts per Million. A measure used in emission analysis.

PROM:  Programmable Read-Only Memory. Similar to ROM, except without program instructions.

Protocol:  A set of rules for the exchange of information on a network.

PSC Module:  Power Steering Control Module

PSR:  Power Sustain Relay

PW:  Pulse Width. The length of time an actuator, such as a fuel injector, remains energized.

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.

PZEV:  Partial Zero Emission Vehicle

Quick Test:  A series of diagnostic tests consisting of KOEO, KOER, and continuous memory self-tests. The resulting DTCs are retrieved using the diagnostic tool.

RAM:  Random Access Memory. Memory into which information can be written as well as read.

RDI:  Restraint Deployment Indicator

REDOX:  Reduction Oxidation Catalytic converter. A catalytic converter system designed to operate at high temperatures.

Relay:  An electromechanical device in which connections in 1 circuit are opened or closed by changes in another circuit.

Repetitive Spark:  Multiple firings of individual spark plugs at engine speeds below 1,000 RPM to improve idle quality and improve emissions.

RF:  Radio Frequency

RFI:  Radio Frequency Interference

RFS:  Returnless Fuel System

RM:  Relay Module. A module containing 2 or more relays.

ROM:  Read-Only Memory. Computer memory that can be accessed and used, but not altered.

RON:  Research Octane Number

Routine:  A group of related tasks, such as a series of diagnostic tests.

RPM:  Revolutions per Minute

RPMDSD:  Desired engine speed

RTN:  Return. A dedicated sensor ground circuit.

RWD:  Rear Wheel Drive

SAE:  Society of Automotive Engineers

SCP:  Standard Corporate Protocol

Self-Test:  See QUICK TEST

Sensor:  A device that detects the value or change in a physical quantity, such as temperature, pressure, or flow rate, and converts the data into an electrical signal.

SFI:  Sequential Multiport Fuel Injection. A multiport fuel delivery system where each injector is individually energized and timed relative to its cylinder intake event.

Shield:  A conducting sleeve that surrounds wires to be electronically isolated from electromagnetic interference (EMI).

Short Circuit:  An undesirable condition in a circuit where the circuit termination is at a point other than that intended.

SHRTFT1:  Short-Term Fuel Trim Bank 1. Fuel flow adjustment in response to the HO2S sensor input during closed-loop operation.

SIG RTN:  Signal Return. A dedicated sensor ground circuit that is common to 2 or more sensors.

Smart Driver:  A PCM or ECU output driver that can detect concerns (open or shorts) on its output circuit.

SME:  Society of Manufacturing Engineers

Solenoid:  A device consisting of an electrical coil which produces a magnetic field which changes the position of a metal plunger.

Stoichiometry:  An air/fuel mixture that is neither too rich nor too lean. Stoichiometric ratio is 14.7 parts of air for every 1 part of fuel.

Switch:  A device for making, breaking, or changing the connections in an electrical circuit.

TACH:  Tachometer

TACM:  Throttle Actuator Control Motor used in the ETC system.

TB:  Throttle Body. A device that controls airflow through the engine via a butterfly valve and has an air bypass channel around the throttle plate.

TBCM:  Traction Battery Control Module

TCM:  Transaxle Control Module

TCM_CAU:  Caution indicator TCM commanded on.

TCM_HAZ:  Hazard indicator TCM commanded on.

TDC:  Top Dead Center

Tear Tag:  The 2-piece adhesive label attached to the PCM to identify its calibration.

TFT:  Transmission Fluid Temperature. Indicates the temperature of transmission fluid.

TGAC:  Torque of Generator AC signal

Thermistor:  A temperature dependent resistor used in CHT and ECT sensors.

Timing:  The relationship between spark plug firing and piston position expressed in crankshaft degrees before (BTDC) or after (ATDC) top dead center of the compression stroke.

TMAC:  Torque of Motor AC signal

TORQUE:  Engine torque TCM received PID

TQ_DSD:  Desired Engine torque TCM received PID

TP:  Throttle Position Sensor. A potentiometer that provides throttle angle and rate information for the PCM.

TP V:  Throttle Position Sensor Voltage

TP_MODE:  Throttle Position Mode

TP_V:  Throttle Position Voltage Input

TPB:  Secondary Throttle Position Voltage Input

TPREL:  Lowest steady TP voltage since engine start

TR:  Gear Position Indicated By Transmission Range Sensor

TR-A Sensor:  Analog Transmission Range Sensor. Provides information to the PCM on the transmission range selector position.

TR_A1, TR_A2, TR_A3:  TR-A 1, 2, and 3 inputs

Transducer:  A device that receives energy from 1 medium and transfers it to another. For example, thermal energy is converted to an electrical signal through a temperature probe.

TRIPCNT:  Number of completed OBD trips

TSB:  Technical Service Bulletin. Notifies the technician of any known vehicle concerns, procedures, or general repair information.

Underspeed Mode:  A control mode that prevents the engine from stalling in the event it stumbles while running. Also used during engine crank.

Vacuum:  Manifold pressure that is reduced below the ambient atmospheric pressure.

Variable Reluctance:  A process of passing a varying magnetic field through wire windings and inducing a voltage.

VBPWR:  Vehicle Buffered Power. A PCM supplied power source that supplies regulated voltage.

VC:  Vehicle Certification

VECI:  Vehicle Emission Control Information label

VEHMODE:  Vehicle operational mode TCM received PID

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. Controls the flow of fuel vapors out of the carbon canister.

VPWR:  Vehicle Power. A switched circuit that provides power to the EEC system. Compare Battery Voltage (B+).

VREF:  Reference Voltage. A dedicated circuit that provides approximately a 5 volt signal used as a reference by certain sensors.

VSC:  Vehicle System Controller

VSS:  Vehicle Speed Sensor. A magnetic pickup device that generates an AC signal that is proportional to the vehicle speed.

WAC:  Wide Open Throttle A/C Cut-Off. Turns the A/C system off during wide open throttle or certain other operating conditions.

WOT:  Wide Open Throttle. A condition of maximum airflow through the throttle body.

Zip Tube:  Another name for fresh air duct or air inlet duct.