How to decrypt OBD2 code (OBD II)

The OBD2 fault code consists of five characters.

The first symbol is "System". The first letter of the fault code identifies the system (part of the vehicle) to which the fault belongs.

• P = Powertrain (engine and / or automatic transmission).
• B = Body (airbags, central locking, power windows).
• C = Chassis (running gear).
• U = Undefined (bus of interaction between electronic blocks).

The second character is "Code type". The second sign indicates the fault code for the general error type (same for all OBD II engines), or it is a manufacturer-specific fault.

• 0 = Generic (common code for OBD2 is a number, not a letter).
• 1 = Enhanced (manufacturer code).
• 2 = Enhanced (manufacturer code).
• 3 = Reserve.

The third symbol is "Subsystem". The third digit indicates the subsystem to which the fault relates.

• 1 = Emission Management (Fuel or Air) (injection control, fuel system or air supply).
• 2 = Injector Circuit (Fuel or Air) (injector circuit, fuel system or air supply).
• 3 = Ignition or Misfire.
• 4 = Emission Control.
• 5 = Vehicle Speed ​​& Idle Control.
• 6 = Computer & Output Circuit (ECU and its external circuits).
• 7 = Transmission.
• 8 = Transmission.
• 9 = SAE Reserved.
• 10 = SAE Reserved.

The fourth and fifth characters are the ordinal number of the error. Together with other symbols indicate the feature of the fault.