ALL ABOUT THE OBD PROTOCOL - OBD1
What is the OBD system?
The OBD system (abbreviations in English for On Board Diagnostics) or Diagnosis on Board, as the name implies, is a system used to perform vehicle diagnostics. With the OBD system you can monitor and control both the engines and some devices integrated to them. Additionally, it is possible to measure the emission levels of gases generated by vehicles and determine whether or not they pollute the environment.
OBD1 was the first OBD standard or regulation, which indicated to the vehicle producers that they had to install a mandatory monitoring system for the devices in charge of controlling gas emissions.
What is the OBD protocol for?
The OBD - OBD1 protocol was created to detect or diagnose vehicle failures. When one of the sensors of a car determines that something is malfunctioning, they send a "Failure Code" or a DTC (Diagnostic Trouble Code), which is reflected by turning on the warning light on the board or table instruments. It also serves to check how pollutant gas emissions are.
These fault codes are manifested by a letter followed by 4 or 5 numbers, such as P0420 indicating a deficiency in the catalytic system.
How does the OBD system of a car work?
This OBD system works with a set of sensors that are connected to an electronic control unit and that together with the computer of the car, can detect or diagnose the faults that are generated in the most sensitive parts, such as, for example, the fuel pump - air, in the electrical system, in the injectors, among others.
When the OBD system detects a fault and turns on the warning light in the instrument cluster, the driver must perform an analysis on the car through an OBD Scanner, which will specify where the problem or fault is located.
Characteristics of the OBD protocol
- The OBD system is installed in both heavy and light vehicles.
- In the beginning, some car parameters could be monitored, such as the EGR system, the control module and the lambda probe.
- It has a double function, since in addition to being a vehicle diagnosis system, the OBD protocol is also a standard for regulating the emission of polluting gases from cars into the environment.
Which cars work with the OBD system?
Because it is a mandatory regulation since 1991, companies such as Ford, Chrysler, Chevrolet and Jeep must incorporate the OBD system in their vehicles.
How to activate the OBD system in a car?
In previous years, to activate this system, the help of a technician or professional, a portable laptop, the OBD cable, a CD with the installation software were first needed. It was done in the following way:
- Locate the OBD port in the vehicle. It is located on the driver's side under the steering wheel.
- The end of the OBD - OBD1 cable must be inserted in the carriage port.
- Install the software on the laptop. Then connect the other end of the OBD cable to the computer port.
- Start the vehicle and at the same time start the software that was installed. Now the portable laptop will record all the data provided by the vehicle's computer, including the failure it presents.
Although the aforementioned process is still used to activate the On-Board Diagnostic system, currently, the same vehicle owner can use an OBD Scanner that synchronized via Bluetooth with a mobile device, can help you obtain all the information from the computer of the car and specifically to find the fault that it is presenting.