| 1970 |
In The United States Congress passes the Clean Air Act and the Environmental Protection Agency (EPA) is formed. |
| 1980 |
Computers start to appear on vehicles, Mainly rising from the need to control the Efi (Electronic Fuel system) in real time. Some simple versions of OBD start to appear but they are not standardised in monitoring or reporting. |
| 1982 |
General Motors start to use their own version of OBD called ALCL (Assembly Line Communications Link), this was later renamed to ALDL (Assembly Line Diagnostics Link). The two terms are used synonymously today Initially the ALCL protocol communicated at 160 baud and used PWM signaling but monitors only a few systems. |
| 1986 |
General Motors introduced an upgrade of the ALDL protocol. The upgrade, which communicates at 8192 baud with half-duplex UART signaling, is known as GM XDE-5024B. |
| 1987 |
The California Air Resources Board required that all new vehicles sold in California from MY1988 had some basic OBD system. The requirements specified are now known as OBD-I standard, interestingly though not this was not enforced until the introduction of OBD-II. The location of the data socket and protocol used are not at this time standardised. |
| 1988 |
A standardised set of diagnostic test signals and diagnostic connector type are recommended by The Society of Automotive Engineers (or as it is better known, the SAE). |
| 1994 |
The California Air Resources Board releases the OBD-II specification and recommended that it be adopted for all cars sold in California starting in MY1996. The connector and DTC's as suggested by the SAE are now included in this specification. |
| 1996 |
The OBD-II specification becomes compulsory for all cars destined for the USA markets. All Jaguars (and some other marques) from this model year are fitted with OBD-II (X300 on) regardless of intended market destination. |
| 2001 |
The European Union announces a variant of OBD-II known as EOBD, this is to be compulsory for all petrol vehicles destined for sale in Europe starting in MY2001 |
| 2008 |
All cars sold in the United States are required to use the ISO15765-4 signaling standard This is a variant of the CAN bus.. |
