° C -   Celsius (Degrees)
CAN - Controller Area Network
CANP -   Canister Purge  
CAS - Crank Angle Sensor 
CAT -   Catalytic Converter
CC -   cubic centimeter
CCC -   Computer Command Control
CCD -   Computer Controlled Dwell
CCW -   Counterclockwise
CID -   Cubic Inch Displacement
CM -   Centimeter
CMP -   Camshaft Position Sensor
CO -   Carbon Monoxide
CO  2   -   Carbon Dioxide
CONV -  Convertible
CP -   Canister Purge
CKP -   Crankshaft Position Sensor
COP - Coil Over Plug Ignition
CPI - Central Port Injection
CPU - Central Processing Unit
CTS -   Coolant Temp Sensor   
CU. IN. -   Cubic Inch
C.V. -  Constant Velocity
CW -   Clockwise
CYL -   Cylinder