I stole the bulk of these. Just trying to get a post here folks can access to look these up (as we all tend to toss them around quite a bit)
If there are any glaring omissions or errors, post em up.
2wd Two Wheel Drive.
4FT Four Wheel Drive, Full Time.
4LO Four Wheel Drive Low.
4PT Four Wheel Drive, Part Time.
4wd Four Wheel Drive.
AAL Add A Leaf.
ABS Anti-lock Brake System.
AC or A/C Air Conditioning.
ACM Airbag Control Module.
AECM Airbag Electonic Control Module.
AEV American Expedition Vehicles. A vehicle modification/conversion shop, located in Montana.
AMC American Motor Corporation. Owners of the Jeep brand from 1970-87.
ARB ARB Corporation named for its founder, Anthony Ronald Brown. Aftermarket manufacturer.
ASDM Airbag System Diagnostic Module.
AT (A/T) All Terrain tire.
ATC Automatic Temperature Control
ATF Automatic Transmission Fluid.
AtoZ A to Z Fabrication. Aftermarket Fabrication.
AVG ECO Average Fuel Economy.
AW4 Automatic Transmission used on the XJ since 1987.
AWD All Wheel Drive.
AX15 5 speed manual stick in a pre-99 6 cylinder TJ.
AX5 5 speed manual stick in a pre-99 4 cylinder TJ.
BB Budget Boost (small, 2" lift, typically a spring spacer lift).
BCM Body Control Module.
BFG BFGoodrich Tires.
BFH Big F-ing Hammer.
BL Body Lift. Spacers between the frame and body/tub of a vehicle.
BPE Bar Pin Eliminators.
BS Backspacing. Wheel hub location in relation to inside edge of rim.
BTT Back To Top.
BTW By The Way.
C-101 Jeepster/ Commando 1967-1973. Part Jeep CJ and part Jeep Wagoneer.
CAB Controller, Antilock Brake.
CAT Catayltic Converter.
CB Citizen Band Radio.
CCD Chrysler Collision Detection (vehicle communications bus).
CCV Crank Case Ventilation.
CEL Check Engine Light.
CG or COG Center of Gravity.
CJ Jeep models 1944-1986.
CJ-2A Civilian version of the MB, split windshield.
CJ-3A Updated version, single pane windshield
CJ-3B High hood version of 3A to fit larger engine
CJ-5 Early years were 81" wheelbase, later years were ~84". Built until 1983.
CJ-5A based on the M38A1 design
CJ-6 Stretch version of CJ-5, 101" wheelbase
CJ-6A based on the M38A1 design
CJ-7 smilar to late CJ-5, but with ~94" wheelbase. Built until 1986.
CJ-8 Scrambler Pickup, stretch version of the CJ-7, 104" wheelbase.
CJ-10 Heavy Duty Truck, Military airport Jeep pickup - 2wheel drive
CMTC Compass/Mini-Trip Computer (module)
COG Center Of Gravity.
CPS Crank Position Sensor.
CV Constant Velocity Joint.
D30 Dana 30 axle.
D35 Dana 35 axle.
D35C Dana 35 axle with C clips. The 'C' stands for custom. They are custom because they are shipped incomplete from the Dana factory to Chrysler. Final assembly was done by Chrysler.
D44 Dana 44 axle.
D44a Dana 44 axle with an aluminum housing
D60 Dana 60 axle.
DAB Driver Airbag
DC Daimler-Chrysler. Owners of the Jeep brand from 1998 until 2007.
DD Daily Driver.
DDM Driver Door Module
DJ AMC 2wd Postal Jeeps. 1952 - 1973
DLC Data Link Connector (same as EDC)
DOHC Dual (or double) OverHead Cams.
DOT Department of Transportation
DRB Digital Readout Box
DRL Daytime Running Lights.
DPA Dropped Pitman Arm
DS Death Shake (same as DW)
DTE Distance To Empty
DW Death Wobble. Violent shaking of the vehicle. (same as DS)
ECO Intantaneous Fuel Economy
ECU Engine Control Unit (same as ECM)
ECM Engine Control Module (same as ECU)
EDC Engine Diagnostic Connector (same as DLC)
EGR Exhaust Gas Recirculation
EFI Electronic Fuel Injection
ET Elapsed Time
FAQ Frequently Asked Questions.
FC Forward Control Trucks 1957 - 1966
FIPK Fuel Injection Performance Kit. Sold by K&N.
FSJ Full Size Jeep (SJ's and J-trucks).
FSM Factory Service Manual.
FWD Front Wheel Drive
GC Grand Cherokee
GPS Global Positioning System.
HCU Hydraulic Control Unit
HD Heavy Duty
HF Harbor Freight. A discount tool store.
HID High Intensity Discharge. A lighting system that produces an intense, white light.
HO High Output
HP High Pinion
HTH Hope this helps, happy to help.
HU Head Unit. The main part of your stereo system.
HVAC Heater, Ventilation, Air Conditioning system.
I4 Inline four cylinder engine.
I6 Inline six cylinder engine.
IAC Idler Air Control Valve
ID or I/D Inside Diameter
IFS Independant Front Suspension.
IOD Ignition Off-Draw
IR Ingersoll Rand. Air tool manufacturer
IRS Independant Rear Suspension.
JK New model Jeep Wranglers made from 2007+
JTEC Jeep Truck Engine Controller (PCM)
KJ Jeep Liberty models from 2002+ (Cherokee in Europe).
LA Long Arm. Refers to length of control arms.
LCA Lower Control Arms. (same as LSA)
LD Left Door.
LED Light-Emitting Diode.
LHS Left Hand Drive.
LJ Unofficial (?) letter code for the Jeep Wrangler Unlimited 2004+.
LOM Lamp Outtage Monitor.
LR Left Rear.
LSA Lower Suspension Arm (same as LCA).
LSD Limited Slip Differential.
LWB Long Wheel Base.
MAP Manifold Absolute Pressure sensor.
MIC Mechanical Instrument Cluster.
MJ Jeep Comanchee, Compact Pickup models from 1986-92.
MML Motor Mount Lift.
MPI Multi-Port Fuel Injection.
MPG Miles Per Gallon.
MPH Miles Per Hour.
MSTM Memory Seat Module.
MT (M/T) Mud Terrain tire.
NP New Process (same as NV).
NP 231 Command-Trac Transfer Case (2HI - 4HI - N - 4LO).
NP 242 Selec-Trac Transfer Case (2HI - 4PT - 4FT - N - 4LO).
NP 247 Quadra-Trac II Transfer Case.
NP 249 Quadra-Trac Transfer Case (4 All Time - N - 4LO).
NV New Venture (same as NP).
NV3550 5 speed manual stick in a post-99 6 cylinder TJ.
NWS Not Work Safe (this thread might get you fired at work)
O2 Oxygen (usually in reference to an oxygen sensor).
OBA On Board Air. A system of a tank and/or air compressor located on a vehicle.
OBD, OBDI First generation of On Board Diagnostics.
OBDII Second generation of On Board Diagnostics (1996+).
OBW On-Board Welder.
OD or O/D Outside Diameter.
OEM Original Equiptment Manufacturer.
OHV Off-Highway Vehicle
OME Old Man Emu. Aftermarket Manufacturer.
ORV Off Road Vehicle.
PAB Passenger Airbag.
PB PB Blaster. A penetrating liquid.
PCM Powertrain Control Module.
PDC Power Distribution Center.
PDM Passenger Door Module.
POS Piece Of Sh--.
PS or P/S Power Steering.
PSI Pounds per Square Inch (of pressure).
PSF Pounds per Square Foot.
PRNDL Park, Reverse, Neutral, Drive, Low.
PRNODL Park, Reverse, Neutral, Overdrive, Drive, Low.
PTC Positive Temperature Coefficient.
PTO Power Take Off.
QD Quick Disconnect. Installed on the anti-sway bar.
RA Road Armor.
RC Reverse Cut.
RD Right Door.
RE Rubicon Express. Aftermarket manufacturer.
RFI Radio Frequesncy Interference.
RHD Right Hand Drive.
RK Rock Krawler. An aftermarket suspension company.
RKE Remote Keyless Entry.
RPM Revolutions Per Minute.
RR Right Rear.
RTI Ramp Travel Index.
RTV Room Temperature Vulcanizing. A product that is used to form gaskets.
SAE Standard American Equivalent. You know, tools that aren't metric.
SAS Solid Axle Swap. Swappnig in a solid front axle to replace IFS.
SE Jeep's basic trim package.
SEMA Specialy Equipment Market Association.
SF Superflex. A lift option for Rubicon Express lift kits.
SFA Solid Front Axle.
SJ Jeep Grand Wagoneers, Trucks from 1963-92.
SOA Spring Over Axle.
SOHC Single OverHead Cam.
SUA Spring Under Axle.
SWB Short Wheel Base.
SWR Standing Wave Ratio.
SYE Slip Yoke Eliminator. Installed on transfer case to decrease driveline angles.
TB Throttle Body.
TBI Throttle Body Injection.
TBS Throttle Body Spacer.
TBT Toys by Troy. Aftermarket Manufacturer.
TC Transfer Case.
TCM Transmisison Control Module.
TJ Jeep Wrangler models from 1997-06.
TJL, TJ-L Unofficial letter codes for Jeep Wrangler Unlimited 2004+.
TPS Throttle Position Sensor.
TRE Tie Rod End.
TSB Technical Service Bulliten.
UCA Upper Control Arms. (same as USA).
USA Upper Suspension Arm (same as UCA).
US/M U.S. to Metric [button].
VC Viscous Coupler.
VF Vaccum Flourescent Display.
VIC Vehicle Information Center.
VIN Vehicle Identification Number.
VSS Vehicle Speed Sensor.
VTSS Vehicle Theft Security System.
WJ Jeep Grand Cherokee models from 1999-04.
WD-40 Water Displacement, Formula 40. A common oil used to do pretty much anything.
WK Jeep Grand Chrokee models from 2005+.
WMS Wheel Mounting Surface.
WOT Wide Open Throttle.
WTF What The F-.
XJ Jeep Cherokee and Wagoneers from 1984-2001.
X Jeep Wrangler Trim/Option Package.
XM A satellite radio service.
YJ Jeep Wrangler models from 1987-95.
ZJ Jeep Grand Cherokee models from 1993-98.