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, 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 also 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 are 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.
- The pinout details are explained here
|Name of PIn
All those pins are nonstandard and vendor specifications. It does not need normal interfacing
|SAE J1850 Bus+
it uses variable pulse width and generally comes in GM vehicles. It is a positive pin
|SAE J1850 Bus-
it is a negative pin used by GM vehicles and comes with the use of variable PW
here ground is connected to the complete car system
|ISO15765-4 CAN High
There is a wire CAN protocol at one Mbps speed followed by this pin and is the high pinout
|ISO15765-4 CAN Low
it is CAN low pin and uses a 2-wire CAN protocol at 1Mbps speed.
|ISO 9141 – K Line
asynchronous serial communication protocol, followed by this
|ISO 9141 – L Line
it also follows asynchronous serial communication protocol,
Types of OBD2 Connectors:
OBD2 Connector Type A and Type B
- Type A of OBD2 connector is used in cars and type B is used in heavy vehicles also in medium vehicles. These two types come with the same pinout but the output supply for them is different. Type A works on type A and Type B on 24 volts
- Type A has a 500K baud rate and type B has 250K.
How Does an OBD2 Connector Work?
The OBD2 gets data from differnt sensors and monitoring components connected engine of the car and other parts. If any issues occur OBD2 computer system analyzes data and DTC or diagnostic trouble. These codes can be read with the use of diagnostic tools that help to find connection issues with car operation
it is done by a connection tool with an OBD2 port that is configured below teh dashboard of the car. The OBD2 prot comes with standard pins that help to connect the diagnostic tool with an onboard computer and get DTC
The pinouts of PBD2 help how every pin on OBD2 functions. There aer 16 pins that do their own function pins 4 and 5 are employed to make ground connections and Pins 2 and 10 are for interfacing with the inter-computer of the car. Pin 6 and 14 are used for the connection of the CAN bus
How to read OBD2 DTC Codes?
There are 4 types of codes. The First DTC character is a letter. There are four types of codes:
- P codes: it is a problem with the powertrain. That can be, transmission, engine drivetrain, and fuel system.
- C codes: It denotes the issues with the chassis. it includes steering, suspension, and braking.
- B codes: B indicates that there is a problem with the body of the car. That is in the passenger compartment area.
- U codes: it is an issue with the vehicle’s onboard computers and integration functions which is managed by OBD
2nd DTC character
can be zero or one but are numeric digits.
- 0: zero is the standard SAE international code. that is a generic code, so it is applicable to all vehicles that is supported by teh OBD-II international standard.
- 1: it is the car’s make or model. Also called enhance code, not lie in SAE standard.
3rd DTC character
If the 2nd DTC character is a zero then the 3rd character helps to find malfunctioning subsystems. That can be 8 digits
|emission controls with Fuel and air metering
|Air and fuel measurement
|Auxiliary emission controls
|idle control systems, Vehicle speed control,
|Computer output circuit
4th and fifth DTC character
These are two-digit numbers from zero to 99 that are called the Specific Fault Index. it helps to find the accurate error of a car or any vehicle
Where is the OBD2 port located in a car?
The OBD-II port normally exists under the dashboard, below the steering wheel column shown in the fgure