POST UPDATED IN August, 2020
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.
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.
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.
Because it is a mandatory regulation since 1991, companies such as Ford, Chrysler, Chevrolet and Jeep must incorporate the OBD system in their vehicles.
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:
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.