Full list standard fault OBD codes

Reading of OBD2 fault codes

Description of the standard trouble OBD codes by family

Standard or generic fault codes are a list of codes common to all manufacturers.
This list of faults, also called DTC (for Data Trouble Code) has been defined so that any diagnostic device can read and decode them. They have a standard format as shown below:

data trouble code P0301

The first letter indicates the family of DTC.

  • P: Powertrain, (i.e. engine and gearbox)
  • C: Chassis
  • B: Body
  • U: User network

The first digit indicates if the code is generic or not (green digit):

  • 0: Generic fault
  • 1: Manufacturer fault
Erase your

As the list of generic OBD codes is not always sufficient, manufacturers can add as many of their own codes as they need.

The last 3 digits correspond to an incremented number (purple digits).
This may be a hexadecimal number (i.e. from 0 to 9 + from A to F). For P family codes, sub-families have been defined using the 1st digit (in this example the "3"):

  • 0 , 1 and 2: for the air/fuel mixture
  • 3 : for the ignition system
  • 4 : for checking auxiliary emissions
  • 5 : for engine idling
  • 6 : for the onboard computer and ancillary outputs
  • 7, 8 and 9: for the transmission (gearbox)
  • A, B and C : for hybrid propulsion

These OBD codes were standardized using SAE J2012 and ISO 15031-6 standards which, to our knowledge, contain about 11 000 definitions in the most recent version.

Below you will find a list of the most commonly used codes. Our software contains all of the 11 000 codes. Don't hesitate to download it. It is free and, using an ELM327 or ELM323 interface, can be used to read the fault codes. For more details, go to our EOBD-Facile car diagnostic software page.

Select the family of the DTC (OBD codes)


/data-trouble-code-obd2.php star star star star star 4.5 14 comments
star star star star star - the 14/08/2019 by Ramir
Great reference! thanks
star star star star star - the 31/07/2019 by Huseyin
star star star star star - the 19/07/2019 by chirpy
Piston app says code iP0520 is: Subsystem- vehicle speed control and idle speed control. Online, the code P0520 says it is oil pressure. Is Piston using standard codes or their own?
star star star star star - the 10/06/2019 by DIY
Nice app. Didn't have a particular code I was looking for, maybe it's me. PO455 code not found.
star star star star star - the 06/05/2019 by frank
I have a random multiple cylinder misfire, on a proton gen 2, what do I do to fix it
star star star star star - the 25/03/2019 by 2019
Great reference! thanks
star star star star star - the 12/01/2019 by cheralon
what a bout a DTC like

"30,12,16 aa : please research before proceeding "?
star star star star star - the 30/12/2018 by Cleveralias
Only reason for 3 star review was due to fact that the code wasn't on the list. But I see how this is very helpful. The code P0455. Evaporative emissions system leak detected (Large leak).
star star star star star - the 18/12/2018 by hawaiianoli
All of you who helped write this literature made it an easy to follow along in layman's terminology!!
Thank you very very much!
star star star star star - the 22/11/2018 by Bossikop
this was the best thing
star star star star star - the 13/11/2018 by Bossiekop
I have a opel astra g 1.6 16v 2002 model. My engine light keeps showing so I had the diagnostic tester plugged in and it shows a 044302 unknown fault code. What can that be? Please help
star star star star star - the 12/09/2018 by coyote
cool save lot of money
star star star star star - the 08/05/2018 by Tim
P0300 Random/Multiple Cylinder Misfire Detected
star star star star star - the 30/04/2018 by Bradley
It's great tool u let me use and I thank u vary much ,,,,but I got a code that says po300. And your code list goes to po299 ,,, what is it that I am missing ,, need info. Thx bunches