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OBDII abbreviations and acronyms

Understanding OBDII abbreviations and acronyms

As you work on your car’s computers and sensors, you’ll see a lot of OBDII abbreviations and acronyms. Here’s a complete list of the abbreviations and what they mean.

ABS: anti lock brake system

A/C: air conditioning
AC: air cleaner
AIR: secondary air injection
A/T: automatic transmission or transaxle
AP: accelerator pedal
APP: accelerator pedal position sensor
B+: battery positive voltage
BARO: barometric pressure
CAC: charge air cooler
CFI: continuous fuel injection
CL: closed loop
CKP: crankshaft position sensor
CKP REF: crankshaft reference voltage
CMP: camshaft position sensor
CMP REF: camshaft reference voltage
CO: carbon monoxide
CO2: carbon dioxide
CPP: clutch pedal position sensor
CTOX: continuous trap oxidizer
CTP: closed throttle position
DEPS: digital engine position sensor
DFCO: deceleration fuel cut-off mode
DFI: direct fuel injection
DLC: data link connector
DTC: diagnostic trouble code
DTM: diagnostic test mode
EBCM: electronic brake control module
EBTCM: electronic brake traction control module
EC: engine control
ECL: engine coolant level
ECM: engine control module
ECT: engine coolant temperature
EEPROM: electrically erasable programmable read only memory
EFE: early fuel evaporation
EGR: exhaust gas recirculation
EGRT: EGR temperature
EI: electronic ignition
EM: engine modification
EPROM: erasable programmable read only memory
EVAP: evaporative emission system
FC: fan control
FEEPROM: flash electrically erasable programmable read only memory
FF: flexible fuel
FP: fuel pump
FPROM: flash erasable programmable read only memory
FT: fuel trim
FTP: federal test procedure
GCM: governor control module
GEN: generator
GND: ground
H2O: water
HC: hydrocarbon

Oxygen sensor related OBDII acronyms

HO2B1S1: upstream heated oxygen sensor bank 1
HO2B2S1: upstream heated oxygen sensor bank 2
HO2B1S2: downstream heated oxygen sensor bank 1
HO2B2S2: downstream heated oxygen sensor bank 2
HO2S: heated oxygen sensor
HO2S1: upstream heated oxygen sensor
HO2S2: downstream heated oxygen sensor
HO2S3: downstream heated oxygen sensor
HVS: high voltage switch
HVAC: heating ventilation and air conditioning system

IA: intake air
IAC: idle air control
IAT: intake air temperature
IC: ignition control circuit
ICM: ignition control module
IFI: indirect fuel injection
IFS: inertia fuel shutoff
I/M: inspection/maintenance
IPC: instrument panel cluster
ISC: idle speed control
KOEC: key on, engine cranking
KOEO: key on, engine off
KOER: key on, engine running
KS: knock sensor
KSM: knock sensor module
LT: long term fuel trim
MAF: mass airflow sensor
MAP: manifold absolute pressure sensor
MC: mixture control
MDP: manifold differential pressure
MFI: multi-port fuel injection
MIL: malfunction indicator lamp
MPH: miles per hour
MST: manifold surface temperature
MVZ: manifold vacuum zone
NOX: oxides of nitrogen
NVRAM: non-volatile random access memory
O2S: oxygen sensor
OBD: on-board diagnostics
OBD I: on-board diagnostics generation one
OBD II: on-board diagnostics, second generation
OC: oxidation catalyst
ODM: output device monitor
OL: open loop
OSC: oxygen sensor storage
PAIR: pulsed secondary air injection
PCM: powertrain control module
PCV: positive crankcase ventilation
PNP: park/neutral switch
PROM: program read only memory
PSA: pressure switch assembly
PSP: power steering pressure
PTOX: periodic trap oxidizer
RAM: random access memory
RM: relay module
ROM: read only memory
RPM: revolutions per minute
SC: supercharger
SCB: supercharger bypass
SDM: sensing diagnostic mode
SFI: sequential fuel injection
SRI: service reminder indicator
SRT: system readiness test
ST: short term fuel trim
TB: throttle body
TBI: throttle body injection
TC: turbocharger
TCC: torque converter clutch
TCM: transmission or transaxle control module
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
VAF: volume airflow
VCM: vehicle control module
VR: voltage regulator
VS: vehicle sensor
VSS: vehicle speed sensor
WOT: wide open throttle
WU-TWC: warm up three way catalytic converter

Posted on by Rick Muscoplat



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