The OBD-II standard on-board diagnostics is a system of rules for collecting, analyzing and transmitting information about the technical condition of a vehicle. Information processing is carried out using special scanners connected to the vehicle through a 16-channel connector.
OBD-II is an on-board vehicle diagnostic standard developed in the United States in the 1990s and then spread to the entire global automotive market. This standard provides for the complete monitoring of the condition of the engine, body parts and vehicle control system.
OBD-II connector
Equipping a car with an on-board diagnostics system of the OBD-II standard provides for a special connector designed to connect control and diagnostic equipment to the car. The OBD-II connector is located inside the cab under the steering wheel and is a block with two rows of 8 contacts. The diagnostic connector is used to power the equipment from the vehicle battery, grounding and information transmission channels.
The presence of a standard connector saves time for car service technicians, which thereby eliminates the need for a large number of separate connectors and devices to process the signals coming from each connector.
Access to information and its processing
The OBD-II standard provides for the use of an error coding system. The error code consists of one letter followed by four numbers, indicating malfunctions of various systems and assemblies of the car. Access to the information transmitted using the on-board diagnostics system allows you to obtain valuable data necessary for a faster and better quality determination of the technical condition of the vehicle and the elimination of existing problems.
In accordance with the ISO 15031 standard, the OBD-II data exchange system has various modes of reading, processing and transmitting information. Car manufacturers decide for themselves which modes to use for a particular car model. Also, manufacturers independently determine which of the diagnostic protocols to use when using the OBD-II system.
There is special equipment for working with data on the condition of the vehicle according to the OBD-II standard. The devices differ in functionality and, in general, are an adapter that is connected to a car using the OBD-II connector and to a computer using a standard USB connector. The set with the equipment is supplied with software, thanks to which the reading and analysis of information is carried out.
