Unlike OBDii error codes, each of the EOBD fault codes consists of five characters. Each code usually includes a letter and four numbers.
The letter, like OBDII, refers to the system related to the error code. For example, P refers to the powertrain system. The second character would be a 0 if complies to the EOBD standard. So if the problem is with powertrain system of an EOBD standard car, the code should look like P0xxx. The third character would refer to the sub-system, for example:
P00xx - Fuel and air metering and auxiliary emission controls.
P01xx - Fuel and air metering.
P02xx - Fuel and air metering (injector circuit).
P03xx - Ignition system or misfire.
P04xx - Auxiliary emissions controls.
P05xx - Vehicle speed controls and idle control system.
P06xx - Computer output circuit.
P07xx - Transmission.
P08xx - Transmission.
The last two characters would refer to a particular problem within each subsystem.