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Terminology 101 *work in progress*

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  • Terminology 101 *work in progress*


    ABS - Anti Lock Braking System, NOT Automatic Braking System
    A/C - Air conditioning
    AC - Alternating Current, like what's in your house
    AIR - Air Injection Reaction
    BCM - Body Controller Module
    BDC - Bottom Dead Center
    CAI - Cold Air Intake, draws air from outside the engine bay
    CCV - Crank Case Ventilation
    CKP Sensor - Crankshaft Position Sensor (also called crank sensor)
    CMFI - Central Multiport Fuel Injection
    CMP Sensor - Camshaft Position Sensor (also called cam sensor) (Saturn S-Series cars do not have these)
    CNP - Coil Near Plug, ignition coil is near spark plugs, but in central location
    COP - Coil ON Plug. Exactly what it says, ignition coil is built into boot, doesn't use conventional spark plug wires.
    CTS - Coolant Temperature Sensor
    DC - Direct current, any current off of a battery
    DI - Direct Injection
    DIS - Distributorless Ignition System
    DOHC - Dual Overhead Cam/Twin Cam
    ECM - Engine Controller Module
    ECTS - Engine Coolant Temperature Sensor
    ECU - Engine Control Unit
    EFI - Electronic Fuel Injection
    EGR - Exhaust Gas Recirculation
    EGR Valve - Device controlled by PCM that controls EGR flow.
    EI - Electronic Ignition
    FI - Forced Induction, extra air forced into engine
    IAC - Idle Air Control
    IAT - Intake Air Temperature
    LCA - Lower Control Arm
    LED - Light Emitting Diode
    MAF - Mass Air Flow sensor
    MAP - Manifold Absolute Pressure Sensor
    MPFI - Multi Port Fuel Injection
    N/A - Naturally Aspirated, air pulled into engine at atmospheric pressure
    OBD1 - On Board Diagnostics system, first design
    OBD2 - On Board Diagnostics system, second design, 1996+ federally mandated.
    OE - Original Equipment
    OEM - Original Equipment Manufacturer
    OHV - Over Head Valve
    OHC - Over Head Cam
    PCV - Positive Crankcase Ventillation
    PCM - Powertrain Control Module
    PFI - Port Fuel Injection
    SOHC - Single Overhead Cam
    SPFI - Sequential Port Fuel Injection
    SRI - Short Ram intake, essentially the same as WAI
    TAM - Torque Axis Mount (also called Third Axis Mount)
    TBI - Throttle Body Injection
    TCC - Torque Converter Clutch/Timing Chain Cover/Timing Control Cover
    TCM - Transmission Controller Module
    TDC - Top Dead Center
    TPI - Tuned Port Injection
    TPS - Throttle Position Sensor
    VSS - Vehicle Speed Sensor
    WOT - Wide Open Throttle

    Common Misconceptions

    Engine - Your engine is not a motor. Engines use fuel, air and an ignition source. Essentially an oversized, fuel driven air pump.
    Motor - electrical, typically via magnetic induction. example-starter, windshield wiper motor, power window motor.
    NOS/Nitrous Express(NX) - These are brands, NOT the actual gas. The gas used is called Nitrous Oxide (N20)
    Transmission - For rear/all wheel drive vehicles with engine facing forwards. (Longitudinally Mounted Engines)
    Transaxle - For front wheel/ all wheel drive vehicles with engine facing sideways. (Transversely Mounted Engines)
    Headers - plural, more than one header. Any inline engine, regardless of # of cylinders cannot have headers.

    Quick Reference

    Alternator - AC Generator, produces AC voltage which is then rectified through a series of diodes (rectifier bridge) into DC voltage.
    Generator - DC generator used in the past (like 70's and before past)
    Ram Air Intake - any intake design which uses air pressure created by vehicle motion to increase the air pressure inside of the intake manifold.
    Header - Better version of an exhaust manifold, manufactured, not cast like a manifold
    Diode - One way resistor that doesn't allow current to flow backwards in a circuit.
    Supercharger - Belt driven forced induction
    Turbocharger / Turbo / Snail - A component of a forced induction system comprised of 5 main components: exhaust housing, exhaust turbine, center cartridge, compressor wheel, and compressor housing. There are smaller pieces within the cartridge that determine the behavior and care required for a turbocharger and a all of the components function differently based on design, but the basic function is as follows: an exhaust gas driven turbine used to create positive atmospheric pressure in the intake charge. This power is derived from a turbine wheel, in the compressor housing, attached to said exhaust turbine via a shaft that connects the two sculpted wheels. The conditions are met when the exhaust gas reaches a certain velocity and overcomes the vacuum of the intake charge. This process is achieved through the compression of the exhaust gas (increase in velocity) which, in turn, pulls even more air into the intake charge due to the compression of the intake charge (increase of velocity and volume due to compression within a closed system

    Engine/Transmission Codes

    LL0 = DOHC 1.9L Saturn engine (twin cam)
    LK0 - SOHC 1.9L Saturn engine (single cam, TBI)
    L24 = SOHC 1.9L Saturn engine (single cam, MPFI)
    L61 = 2.2L Ecotec engine
    LE5 = 2.4L Ecotec engine
    LSJ = 2.0L Ecotec engine (supercharged)
    LAT = 2.4L Ecotec engine (hybrid)
    L81 = 3.0L V6 engine
    L66 = 3.5L V6 engine
    LZ4 = 3.5L V6 engine
    LK9 = 3.5L V6 engine
    LY7 = 3.6L V6 engine
    LLT = 3.6L V6 engine
    LZ9 = 3.9L V6 engine
    LGD = 3.9L V6 engine (E85 flex fuel)

    MP2 - Saturn SOHC Manaul transaxle
    MP3 - Saturn DOHC Manual transaxle
    MP6 - Saturn SOHC Automatic transaxle
    MP7 - Saturn DOHC Automatic transaxle
    F23 = 5 speed Getrag transmission M86/M94
    4T40-E = 4 speed automatic transaxle (4cyl)
    4T45-E = 4 speed automatic transaxle (6cyl)

    Tire Reference

    P - Passenger (or LT - Light Truck
    205 -Tread width in millimeters
    55 - % height of side wall, based on tread width. example 205/55 means the sidewall is 55% as tall as the tread is wide
    R15 - Radial (The make up of the tire belt) and Rim size.

    Example: P205/55R15 91W M+S

    P: Passenger
    205: Tread Width (mm)
    55: Section width (%)
    R: Radial
    15: Rim Diameter (inches)
    91W: Service Description (Load and speed rating)
    M+S: Mud & Snow
    Last edited by slipstreamconversion; 02-22-2014, 11:20 AM. Reason: Cleaned up, added info from Steve
    1G8ZJ5472MZ134321-Jaded, my first, and favorite, still missed every day.
    1G8ZF5594PZ249184-Trinity, Parted Out-Bye old pal, been a hell of a ride.
    2C1MR2224Y6709630-DD, '00 Metro LSi, rebadged as Saturn Tau, because I can that's why.

  • #2
    Cleaned up the main post and whole thread.

    Many people have contributed to this thread, so if you find any errors let us know!

    Anyone who wants to add anything to this automotive terminology 101 thread can certainly post here and I'll add her in
    Last edited by slipstreamconversion; 02-22-2014, 11:20 AM.
    - Sixthsphere Admin Team -


    • #3
      Ptb-part trottle boost.
      72 Charger: pissed me off, on jackstands.
      95 SW1m: Dohc swap. DD. I can haz boost?


      • #4
        Under "headers" it states that all inline engine have only one header...which is not true. The are rare occasions that inline 6's will have two 3-runner headers.
        -6S Resident Mechanical Forensics member #001.
        1995 SC2 Turbo 3.6L DOHC, 6sp manual, Ford 8.8 rearend running on MS3x.
        1998 F-250 5.4L triton...stock.


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