The data link connector (DLC) is the multi-pin
diagnostic
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...
connection port for
automobiles, trucks, and motorcycles used to interface a
scan tool with the
control modules of a given vehicle and access
on-board diagnostics and live data streams.
Prior to 1996, many OBD-I data link connector's were in the engine compartment, usually near the fuse block. Also, prior to 1996, there was no standardization for these connectors, and each manufacturer had its own shape with a unique pin arrangement. After 1996, many manufacturers retained their proprietary connectors in addition to the OBD-II interface, because OBD-II ports are only required to transmit
emission-related codes and data.
J1708
Society of Automotive Engineers standard SAE J1708 is a standard used for serial communications between ECUs on a heavy duty vehicle and also between a computer and the vehicle. With respect to Open System Interconnection model (OSI), J1708 defin ...
is a DLC used on heavy duty vehicles.
OBD-II diagnostic connector
The
OBD-II
On-board diagnostics (OBD) is a term referring to a vehicle's self-diagnostic and reporting capability. OBD systems give the vehicle owner or repair technician access to the status of the various vehicle sub-systems. The amount of diagnostic inf ...
DLC (post-1996 vehicles) is usually located under the
instrument panel on the driver side, though there are several exceptions. The SAE J1962 specification provides for two standardized hardware interfaces, called ''type A'' and ''type B''. Both are female, 16-pin (2x8), D-shaped connectors, and both have a groove between the two rows of pins. But type B has the groove interrupted in the middle, so it isn't possible to plug a type A male connector into a type B socket. It is possible, however, to mate a type B male plug in a type A female socket.
The type A connector is used for vehicles that use 12V supply voltage, whereas type B is used for 24V vehicles and it is required to mark the front of the D-shaped area in blue color.
The OBD-II connector is required to be within of the steering wheel or somewhere within reach of the driver.
See also
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On-board diagnostics
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OBD-II PIDs
OBD-II PIDs (On-board diagnostics Parameter IDs) are codes used to request data from a vehicle, used as a diagnostic tool.
SAE standard J1979 defines many OBD-II PIDs. All on-road vehicles and trucks sold in North America are required to support a ...
– list of data readable with a scan tool
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ELM327
The ELM327 is a programmed microcontroller produced for translating the on-board diagnostics (OBD) interface found in most modern cars. The ELM327 command protocol is one of the most popular PC-to-OBD interface standards and is also implemented by ...
– common integrated circuit inside scan tools
*
OBDuino
OBDuino is an open source trip computer design based on the Arduino platform. An OBDuino may be assembled and customised by an electronics hobbyist; it displays information such as instantaneous fuel economy (e.g. miles per gallon, L/100 km o ...
– onboard computer made with Arduino that has the scan tool functions
References
Automotive electronics
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