Hello, friends welcome to the new tutorial. In this post, we will learn about Introduction to ODB-II Connector. The full form of OBD is onboard built-in diagnosis. It is diagnosis modules that are employed in currently used cars. It helps to regulate and observes the speed mileage and fuel emission report of cars.
It also helps to monitor the performance of the engine. It is also called ECU or engine control unit. Here we discuss its different features working, pinouts, and practical applications. So let’s get started with Introduction to ODB-II Connector.
Introduction to ODB2 Connector
- OBDII is a diagnostic module that is used in different types of cars to monitor the operation of that car.
- The get through these modules from the engine control unit helps to make the overview of cars when any fault exists in that car.
- For practical observing, these modules look at your car dash where it exists.
- It relies close to the steering wheel of a vehicle and also on can exist close to covers
- Before making the male connectors to OBD2 female connectors make sure they fit to this category.
- The pinout number sixteen of this module gets the power from the battery of the car.
How to Log OBD II data
- There is some processes to log in the data.
- First of all links the OBD2 logger with the connector
- Send the request frames through CAN
- The correspondent engine controls negative response frames through CAN.
OBD2 Pinouts
- The pinout details are explained here
| Pin | Function | Explanation |
|---|---|---|
| 1 | Ground | gives the diagnostic instrument a ground connection. |
| 2 | Power (12V) | gives the diagnostic instrument a ground connection. |
| 3 | CAN H (High) | used to facilitate communication between a diagnostic instrument and the vehicle’s computer. The two devices connected by this pin communicate via a high-speed serial protocol. |
| 4 | CAN L (Low) | used for communication between a diagnostic instrument and the car’s computer. Data is sent between the two devices using a high-speed serial communication protocol through this pin. |
| 5 | Ignition Switch (Key On) | When the ignition is turned on, it powers the diagnostic instrument. This enables the diagnostic tool to be utilized even while the engine is not operating in order to obtain diagnostic trouble codes (DTCs) and other information from the vehicle’s computer. |
| 6 | Chassis Ground | gives the car’s computer a link to the Earth. The computer in the car needs this to operate correctly. |
| 7 | The engine Coolant Temperature Sensor | gives the engine coolant sensor’s temperature data. The computer in the car uses this data to regulate the ignition timing and fuel mixture. |
| 8 | Mass Air Flow Sensor | gives the mass air flow sensor measurement for the air volume. The computer in the car uses this data to regulate the fuel mixture. |
| 9 | Throttle Position Sensor | gives the throttle position sensor’s reading for the position of the throttle. The computer in the car uses this data to regulate the ignition timing and fuel mixture. |
| 10 | Oxygen Sensor 1 (Pre-Cat) Voltage | The initial oxygen sensor’s voltage measurement (from the pre-catalytic converter) is provided. The computer in the car uses this data to regulate the fuel mixture. |
| 11 | Oxygen Sensor 1 (Pre-Cat) Ground | gives the primary oxygen sensor (pre-catalytic converter) a ground connection. |
| 12 | Oxygen Sensor 2 (Post-Cat) Voltage | Provides the voltage reading from th 2nd oxygen sensor (post-catalytic converter). This information is used by the vehicle’s computer to control the fuel mixture. |
| 13 | Oxygen Sensor 2 (Post-Cat) Ground | used to provide a ground connection for the second oxygen sensor (post-catalytic converter). |
| 14 | Fuel System Status | Provides data about the fuel system. This data can be used to diagnose issues the fuel system. |
| 15 | Diagnostic Trouble Code (DTC) Request | Used to request diagnostic trouble codes from the vehicle’s computer. DTCs are codes that indicate problems with the vehicle’s emissions control system. |
| 16 | Reserved | Not used for anything. |
Types of OBD2 Connectors:
OBD2 Connector Type A
The 16 pins of Type A connectors are organized in two rows of eight. They are frequently seen in automobiles made by General Motors (GM) and a few other brands. These connections have a rectangular form and are frequently black in color.
OBD2 Connector Type B
In contrast to Type A connections, Type B connectors are more square in design and feature 16 pins grouped in two rows of eight. Several European brands including Ford and Mazda automobiles are the most common places to find them. Green is a common color used to denote Type B connectors.
OBD2 Connector Type C
Micro-USB connections, sometimes referred to as Type C connectors, are a more recent development in the OBD2 connector family. They have a trapezoidal form with a more compact, smaller design. The pin configuration of Type C connections, which feature 16 pins, may be different from that of Type A and Type B connectors. There are more of these connectors in more recent autos from different manufacturers.
How Does an OBD2 Connector Work?
The onboard computer system of the car can be directly connected to an external device, such as a smartphone or diagnostic equipment, using the OBD2 port. When connected, the external device may communicate with the OBD2 system to issue commands and receive useful data in response. The connection enables data transmission using the established protocol and supplies power to the external device.
The information accessible via the OBD2 connector includes details about the engine’s RPM, the vehicle’s speed, the temperature of the coolant, the condition of the fuel system, the readings from the oxygen sensors, and much more. This information is necessary for monitoring performance, diagnosing engine difficulties, and spotting prospective issues before they become more serious.
How to read OBD2 DTC Codes?
Step 1: Locate the OBD2 Connector
In your car, find the OBD2 connection. Usually, it can lie beneath the dashboard, and close the steering wheel. The connection has 16 pins and is rectangular in form. It could be covered with a plastic cap or panel, based on the manufacturer and model of the car.
Step 2: Power On the Scanner
Make sure the ignition is off in your car. Connect the diagnostic tool or OBD2 scanner to the connection. Follow the manufacturer’s instructions to turn on the scanner. While some scanners get power directly through the OBD2 port, some use an external power source, like car’s battery.
Step 3: Establish Connection
The scanner will link to the car’s onboard computer system as soon as it is turned on.. To traverse the menu selections and choose the correct vehicle make and model, follow the on-screen prompts or refer to the scanner’s user manual.
Step 4: Retrieve DTCs
Decide whether to read or recover DTCs from the car’s computer. The saved DTCs will be retrieved by the scanner after it has communicated with the onboard computer system. According to the model, the scanner will either print out the codes or display them on its screen.
Step 5: Interpret the DTCs
A collection of alphanumeric characters make up each DTC. They are standardized codes that give details about the particular problem identified. To interpret the DTCs, consult the user handbook for the scanner or an OBD2 code reference manual. Different categories, including P (Powertrain), C (Chassis), B (Body), and U (Network), are used to group the codes.
Step 6: Diagnose and Address the Issue
Following the identification of the DTCs and comprehension of their implications, you may go on to the diagnosis and treatment of the underlying issue. The DTCs assist identify potential problems and act as a starting point for troubleshooting. In order to decide what the best course of action is for addressing the problem is, it’s crucial to speak with a competent technician or adhere to repair instructions and recommendations.
Step 7: Clearing DTCs (Optional)
You have the option of erasing the DTCs from the car’s computer system after you’ve identified and fixed the issue. The OBD2 scanner can be used for this extra stage. The scanner will speak with the onboard computer to reset the codes if you choose the option to clear or erase DTCs. Be aware that clearing the DTCs will also force the vehicle’s readiness monitors to reset; this process can take a few driving cycles to complete.
Remember, it is always advised to get expert assistance from a licensed mechanic or technician if you are unclear how to interpret the DTCs or carry out any repairs. They are equipped with the knowledge and specific tools needed to accurately identify and address complicated problems.
Where is the OBD2 port located in a car?
The OBD2 (On-Board Diagnostic) port is normally found inside an automobile, more especially on the driver’s side under the dashboard. It is frequently placed next to the steering wheel for convenience. Depending on the make and type of the car, the precise placement could differ slightly, but it’s often close to the steering wheel.
Start by looking under the dashboard, next to the driver’s side footwell, to find the OBD2 port. Look for a 16-pin, rectangular connection that is the same size and shape as the OBD2 connector. A plastic panel or cap that covers the port may be easily removable to show the connection.
If you’re having difficulties locating the OBD2 port, the owner’s handbook for your car might provide you with detailed directions and pictures of where it is. Additionally, there are internet sites that offer in-depth details on OBD2 port placement, so you may look up the position of the OBD2 port for your specific vehicle’s make and model there.
How to use the OBD-II Connector with Arduino/Raspberry Pi?
Step 1: Gather the Required Components
You will require the following components to start:
- OBD-II to UART converter (like the ELM327) for an Arduino or Raspberry Pi board
- connecting cords (GPIO for Raspberry Pi or USB for Arduino)
- OBD-II communication software libraries, such as the Arduino OBD-II library or the Python OBD library for the Raspberry Pi
Step 2: Connect the OBD-II Adapter to the Board
Utilizing the proper wires, attach the OBD-II to the UART adapter to the Arduino or Raspberry Pi board. A USB cable can be employed to connect Arduino to the computer. Connect the OBD-II adapter’s matching pins to the Raspberry Pi’s GPIO pins.
Step 3: Install the Required Libraries
Install the required software libraries for OBD-II connection depending on your board. The Arduino OBD-II library, which offers functions to interface with the OBD-II, can be used with Arduino. The Python OBD library is often used and can be loaded on Raspberry Pi via pip.
Step 4: Upload the Sketch (Arduino) or Write the Code (Raspberry Pi)
You must submit the sketch for Arduino that contains the OBD-II adapter communication code. Instructions for connecting to the adapter and obtaining data from the car’s onboard computer system should be included in the drawing. The documentation for the Arduino OBD-II library contains examples of sketches.
Create a Python script for the Raspberry Pi that makes use of the Python OBD library. The script must connect to the OBD-II adapter and issue instructions for data retrieval from the car. Documentation for the Python OBD library includes sample code and usage guidelines.
Step 5: Connect to the Vehicle
The OBD-II port beneath the dashboard of the car should be connected to the OBD-II adaptor. Make sure the engine is not running but the ignition is switched on. The onboard computer system of the car will be connected through the OBD-II adaptor.
Step 6: Run the Code
To observe the data collected from the car using an Arduino, open the serial monitor in the Arduino IDE after uploading the project. Depending on your needs, you may edit the code to show particular data or carry out particular activities.
Run the Python script in on a Raspberry Pi. According to your code, the script will interface with the OBD-II adapter and show the data it has collected or take particular actions.
Step 7: Interpret and Use the Data
You can obtain information from the car’s onboard computer system, like engine RPM, speed, coolant temperature, and more, thanks to the code you’ve developed. Based on the needs of your p project or application, interpret and apply the data.
To guarantee effective communication with the OBD-II adapter and for full usage instructions, always refer to the documentation and examples offered by the relevant libraries.
That is all about ODB-II Connector. I have explained all details about ODB-II Connector if you have any further query ask in the comments. thanks for reading have a good day.
