What is On-Board Diagnostic II System and Scanner?

Board Diagnostic II

For a long time now, vehicles have stored information in their black boxes to gather data regarding fuel consumption and movement patterns and report issues and trigger warnings.

In a car, the system responsible for this is often referred to as the On-Board Diagnostic System.

The On-Board Diagnostic System refers to a vehicle’s capability to self-diagnose and report problems found.

This system was discovered in cars in 1968 when Volkswagen made the first known OBD system with Scanning capability in their Volkswagen 3 cars.

It was standardized in 1994 and named On-Board Diagnostics (OBD) II.

In a nutshell, it merely monitors how, when, and where a vehicle is being driven, records the information, provides analysis as feedback to the driver, and alerts the driver whenever there is an issue.

The OBD II System monitors inputs and outputs sent by a vehicle’s sensor.

It throws an error code (Diagnostic Trouble Code) which triggers the check engine light when encountering anything unusual.

check engine light

The check engine light is the OBD II system’s way of telling you if there is a malfunction with your car.

It either blinks steadily to indicate a minor fault or repeatedly flashes to show a critical fault.

Diagnostic Trouble Code

Diagnostic Trouble Codes (DTC) are codes generated by the car and sent to the OBD system, and they are unique, with each code detailing a problem.

The code has five unique parts starting with an alphabet and four-digit numbers such as B0324.

Source; Trouble-Codes

The alphabet part has four alphabets (B, C, P, U) depicting where the fault originates from. B is for the body category, which covers function with the passenger’s compartment; C is for the Chasis category covering suspension, brakes, and steering; P represents Powertrain, which includes engine and transmission; and U represents network communication.

The first digit of the DTC might be 0 or 1. Codes that start with 0 merely indicate that the car is following the global OBD II Standards, and the fault can be found in other cars, while manufacturers make codes beginning with 1 and are unique to them only.

Manufacturers rely on that code to provide additional information beyond that contained in the Standard OBD Codes.

The second digit depicts the subsystem that the fault is generating from, such as Transmission, Computer Output Circuit, Ignition System, etc.

It ranges from 1 – 8. The last two digits depict the actual problem as it helps to point out the description of the fault.

OBD II Scanner

When the check engine light is triggered, the information stored in the car’s OBD system will have to be read to know the fault.

The OBD II System has a data processor connection port (the OBD port) underneath the driver dashboard located within two feet of the steering wheel, where an OBD Scanner can be plugged in to read the data.

The OBD II Scanner is a tool connected to the OBD port of an automobile as a diagnostic tool to get information on what is wrong with the car.

The scanner serves as an interface that enables you to monitor crucial systems and functions in your ride.

Output displayed by the OBD Scanner depends on the type of scanner being used.

There are many scanners; however, they are sorted into two basic categories: Code Readers and Scan Tools.

The Code Readers display the DTC on the OBD Scanner interface with no additional information whatsoever.

The car owner or engineer would have to be compelled to search for codes in a code chart to aid diagnosis.

Code scanners are cheap but limited in fault reporting, and it wasn’t until now that they had computer software created for them to provide detailed diagnostic reports.

The Scan Tools are more expensive, have a variety of features, and provide an in-depth report on faults encountered in addition to proffering troubleshooting solutions.

It displays the DTC codes as well as the fault, and most scan tools have laptop programs and mobile apps to assist in fault diagnosis and proffering solutions.

There are OBD dongles too that fall under this category, which offer real-time monitoring using either Bluetooth or Wi-Fi for reporting.

Bluetooth and Wi-Fi Dongles are mostly utilized alongside phones, and a good example is the Torque OBD2 Bluetooth Adapters and Dash.

How to Use the OBD II Scanner for Fault Diagnosis

Using the OBD II Scanner requires the following three necessary steps without the need for any technical knowledge;

  1. Turn off the automobile and connect the Scanner to the data processor port.
  2. Turn on the ignition and push the red button on the code scanner or select the read codes option on the scan tools.
  3. Disconnect the Scanner. After that, the scanner’s data can aid further troubleshooting and quick fixes.

Advantages of the OBD II Scanner

The most vital benefit of the OBD II Scanner is that it is used to diagnose the cause of check engine lights.

The OBD II Scanner will direct you to where the problem is coming from, thus saving you time as you or the auto mechanic will not have to waste time trying to figure out what the problem is

It helps in verifying repairs. With the OBD Scanner, you can check if the error is still present once the auto mechanic claims to have fixed the car.

It can also be used for performance tuning. Also, some new Dongles are GPS enabled, thus helping you track your car.

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