OBD-II Stands For Second Generation On-Board Diagnostics Codes
OBD-II Stands For Second Generation On-Board Diagnostics Codes

Choose Your OBD-II Help Topic Below

OBD-II Stands For Second Generation; On-Board Diagnostics Codes

P0001 Through P0099 – Fuel & Air Metering – Auxiliary Emission Controls

P0100 Through P0199 – Fuel and Air Metering – With Testing

P0200 Through P0299 – Fuel and Air Metering (Injector Circuit)

P0300 Through P0399 – Ignition System or Misfire – With Testing

P0400 Through P0499 – Auxiliary Emissions Controls – With Testing

P0500 Through P0599 – Vehicle Speed Controls and Idle Control System

Diesel Common Check Engine Light; Diagnostic Trouble Codes

P0008-U1601 Dodge Cummins Diagnostic Trouble Codes

P0100-P0804 Chevy/GM Duramax Diagnostic Trouble Codes

P1111-P1783 Ford Power-stroke Diagnostic Trouble Codes

The Story Of OBD-II

What was OBD I?

So, (OBD I) was California’s first (OBD) regulation. Consequently, requiring manufacturers to monitor; the emission control components. So, starting with the 1988 model year; (OBD) I systems were not fully effective. Because, they were limited to monitoring only; a few of the emission related components. But, the monitors were not calibrated; to a specific level of emission performance.

What is OBD II?

So, OBD-II is an acronym for; On Board Diagnostic II. The second generation of; on board self diagnostic equipment. Also, if a problem or malfunction is detected; the OBD-II system; illuminates a warning light. As a result, this warning light will display the phrase; “Check Engine” or “Service Engine Soon”. Furthermore, the system will store information; about any detected malfunction. So, that a repair technician can find and fix the problem.

Why is OBD so important?

OBD is an important part of telematics and fleet management; making it possible to measure and manage vehicle health and driving.

Thanks to the OBD, fleets can:

  • Track wear trends and see what vehicle parts are wearing out faster than others.
  • Instantly diagnose vehicle problems before they occur, supporting proactive rather than reactive management.
  • Measure driving behavior, speed, idling time and so much more.

What should I do if the warning light comes on?

Consequently, there are many problems that; can cause the light to illuminate. So, it is hard to generalize how severe a problem may be. Additionally, there are certain malfunctions; that can cause the warning light to blink. Finally, this indicates that a malfunction is occurring; that could be damaging your catalytic converter.


OBD-II not only controls engine functions, but also monitors other vehicle components like; chassis, body, accessory devices like mirrors, wipers etc. And, also the diagnostic control network of the vehicle. It also follows the California Air Resources Board (CARB) guidelines; for data storage and accessibility to be provided to the external scan tools. Thus OBD-II is a protocol for vehicle diagnostics communication.

Thank You !