What is the OBD port and what it is used for?

Most of the owners have heard of the OBD port , but where  exactly is a OBD port location  ? What is this used for?

When we go to car maintenance shop, we will see a mechanic take a dedicated computer tester, accessing to the invisible position of the socket, and then the vehicle’s fault code is cleared.

The throttle after cleaning is no longer has an error. In fact, this port  is not as mysterious as the imagination, and for the owner, learn to use OBD interface can make you become a car master .

obd-port-location What is the OBD port and what it is used for?

What is the meaning of OBD?


OBD as a proper noun abbreviation, it is all called On Board diagnostics.

This system can do real-time monitoring for engine electronic control system and other functional modules when vehicle running

if found abnormal conditions,  it will determine the  fault according to specific algorithm, and store the data  in the form of diagnostic fault codes (DTC, Diagnostic trouble codes).

After the system has been diagnosed, the useful information will be helpful for the maintenance of the vehicle.

Maintenance staff can read the fault code by using the car’s original special instrument . so that the fault can be quickly positioned and reduce the artificial diagnosis time .

obd-port-location What is the OBD port and what it is used for?

obd-port-location What is the OBD port and what it is used for?

Difference between OBD1 and OBD2 ?


Initial OBD system (obd1)  has different manufacturers and they were independent and incompatible. in order to unify the standards, the American Association of Automotive Engineers (SAE, Society of Automotive engineers) in 1988 set the OBDII standard.

OBDII implements standard testing procedures and has strict emissions targeting for real-time monitoring of vehicle exhaust emissions.

As a system to monitor exhaust emissions, OBD has gradually expanded its scope of control in the later development. with the increase of various sensors and electronic degree of vehicles, the OBD has incorporated various monitoring functions into its own jurisdiction.

obd-port-location What is the OBD port and what it is used for?

Now we’re talking about OBD generally using the word OBD port , because we can only see the transmission interface of the system in the vehicle, but it’s combined the whole vehicle control system in back.


The early OBD interface uses the K-line communication method which is based on the ISO protocol. It connects with the external device through the computer standard serial port communication way.    But the efficiency is low, so this kind of communication way basically has been eliminated.

In recent years, , CAN-BUS has the very strong expansibility, the popularization of this agreement has made the vehicle detection work greatly simplified, A tester can be used to detect multiple brands of vehicles.

What does a obd2 Scanner do?

OBD2 scanner have below 3 basic function . If you want to know what is the best obd2 scanner ,

please refer to 5 Best OBD2 Scanners in 2017

 1.computer data display

OBD Port  as the communication interface of vehicle monitoring system, in addition to reading the fault code to repair the car, the primary function is to provide a variety of vehicle operating conditions.

Except for the vehicle display data, the actual data recorded in the driving computer is much more including a lot of vehicles without a traffic computer display configuration. In fact, the various fuel consumption records, battery voltage, air-fuel ratio, throttle opening, number of explosions and other data are recorded in the system. but some OEM manufacturers remove the traffic computer display due to price allocation and other factors in the lower configuration model vehicle.

It makes users can not refer to these useful data, Therefore, there are some special  computer display products on the market.

obd-port-location What is the OBD port and what it is used for?

There are two types of this product, one is connected to the vehicle’s OBD interface through a dedicated data line. The data read out and then displayed to the matching display. It is equal to install a traffic computer displays.

obd-port-location What is the OBD port and what it is used for?


Another type of product is the wireless OBD interface adapter + smartphone-side software. This OBD port reader transmits the OBD interface to the smartphone by Bluetooth or WiFi, and presents it to the user through the software on the handset side.

obd-port-location What is the OBD port and what it is used for?

2. Change the code to achieve more functionality

obd-port-location What is the OBD port and what it is used for?

Today’s electric control system can access the CAN-BUS  of the vehicle control system through the OBD interface. It can adjust the function of each control module of the vehicle.

The most famous application is the data line developed by Ross Tech and the VCDS system diagnostic software.

Most of drivers love to use this equipment to adjust the system of public cars system functions.


3.Read ,Brush and  Write ECU TCU program

obd-port-location What is the OBD port and what it is used for?

With the hardware upgrade of the onboard computer system, the program memory of the electronic control unit of the modern vehicle is changed from the previous read-only to the brush able type.

The company is set up to keep the ECU Control procedures to update, like the phone’s firmware upgrade .  Engine will adapt to a variety of different working environments for different driving areas or conditions through the upgraded ECU system program.

Taking the stability and economy of the original ECU program into consideration , it is generally reserved the power output .

And  tuning manufacture can improve the power out by modifying the original ECU data .

Modified program can make the automatic transmission smart and  improve the performance of the vehicle .

Everything will be easier when you have the obd port  .Just connect your computer to the port by data wire and complete your work .



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