Firstly, OBD-II is an upgrade, from the original system, in earlier vehicles.

With advancements in technology, came improvements and the second generation system was introduced.

As a result, they all use a, standardized digital communications port, that provides real-time data. This results in, much faster diagnostics, of a vehicle’s problem.

In addition, if a problem or malfunction is detected, the OBD-II system, illuminates a warning light. Consequently, this warning light will display the phrase; “Check Engine” or “Service Engine Soon”. Furthermore, the system will store information, about, any detected malfunctions.

Firstly, the OBD-II on-board computer features, a 16-pin port, located under the driver’s side dash. Furthermore, it allows a mechanic or anyone else; to read the error code, using a special scan tool.

So, 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 other malfunctions, that can cause the warning light to blink. The reason any OBD-II scan tool can read the codes is, because of the standardized pinout.

The standardized pinout is as follows:

  • Pin 1: Used by manufacturer
  • 2: Used by SAE J1850 PWM and VPW
  • 3: Used by manufacturer
  • 4: Ground
  • 5: Ground
  • 6: Used by ISO 15765-4 CAN
  • 7: The K-Line of ISO 9141-2 and ISO 14230-4
  • 10: Used only by SAE J1850 PWM
  • 14: Used by ISO 15765-4 CAN
  • 15: The K-Line of ISO 9141-2 and ISO 14230-4
  • 16: Power from the car battery
OBD-II Connector And Pinout
OBD-II Connector And Pinout

In other words, OBD-II scanners can connect to these ports and identify the engine codes; from any manufacturer that uses one of the OBD-II protocols.

It not only controls, engine functions, but also monitors, other vehicle components like:

  • Engine Misfires.
  • Emissions Control Systems.
  • Vehicle/Speed Idling Controls.
  • Computer Systems.
  • Transmission Systems.
  • Seat-belt, Airbags.
  • Vehicle Body & Chassis.
  • Accessory Devices.
  • Variable Valve Timing.

Finally, 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.

Choose Your OBD-II Help Topic Below

P0001 Through P0099 – OBD-II Trouble codes, fuel and air metering.

P0100 Through P0199 – OBD-II Trouble codes, fuel and air metering.

P0200 Through P0299 – Fuel and air metering (Injector Circuit).

P0300 Through P0399 – Ignition system or engine misfire.

P0400 Through P0499 – Auxiliary emissions controls.

P0500 Through P0599 – Vehicle speed and idle control system.

Diesel Engine, 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.

Thank You !