You may look for OBD-II code or for those who have Open SID function available by the code that you see on the SID (System Information Display).
Example: ODB-II Code P0420 = SID Code 1056

Insert the full error code

OBD-II codes explained

Letter - System
The first character identifies the system related to the trouble code.
P = Powertrain
B = Body
C = Chassis
U = Undefined

First Digit - Code Type
The first digit identifies whether the code is a generic code (same on all OBD-II equipped vehicles), or a manufacturer specific code.
0 = Generic (this is the digit zero -- not the letter "O")
1 = Enhanced (manufacturer specific)

Second Digit - Sub-System
The third digit denotes the type of sub-system that pertains to the code
1 = Emission Management (Fuel or Air)
2 = Injector Circuit (Fuel or Air)
3 = Ignition or Misfire
4 = Emission Control
5 = Vehicle Speed & Idle Control
6 = Computer & Output Circuit
7 = Transmission
8 = Transmission
9 = SAE Reserved
0 = SAE Reserved

Third and Fourth Digits
These digits, along with the others, are variable, and relate to a particular problem.