I've been reading a few articles and noticed some people throwing around terms incorrectly. I thought I would make a quick post.

PCV = Positive Crankcase ventilitation
EGR = Exhaust Gas Recirculation
H02S = Heated 02 Sensor
PCM = Powertrain Contol Module (Integerated TCM and ECM)
TCM = Transmission Control Module
ECM = Engine COntrol Module
ECU = Electronic control unit
TPS = Throttle Position Sensor
ECT = Engine Coolant Temp
IAT = Intake air temp
MAF = Mass air Flow
BCM = Body Control Module (Also known as smart entrance control unit on Nissans)
MAP = Manifold absolute pressure (Also known as vacuum)
KS = Knock Sensor
OBD II= On board Diagnostics second generation(96 and later automobiles)
OBD = On board diagnostics
CKS = Crankshaft position sensor
CPS = Camshaft position sensor (Alot of technicians refer to cps to crankshaft position sensor - This was CKS term before OHC)

Feel free to add or edit any of the information.

 

ECU=http://autorepair.about.com/cs/generalinfo/l/bldef_160.htm

 

Intresting...So the ECU is basically another term for PCM....Guess I have taken from the incorrect knowledge on this board myself. ...
I wonder if the ECU is the "electronic control unit" then how can alldata list a ECM???
I have edited my first post

 

ECM/ECU are the more common terms for what Chrysler calls a PCM or Powertrain Control Module. Chrysler's PCM is a bit misleading since it controls many things other than the engine and transmission.