It's been a wonderful and quite stressful day, I will try and enlighten the public more on the OBD communication link with your car as promised. But first things first, hope everyone is in perfect shape and condition?
The OBD system has a port on each and almost every car, in the earlier models of cars with this port you would find it under the hood of your vehicle, that indicates that your vehicle is running on the OBD I system.
On the vehicles with OBD II you would find the port at most 2 feet from the drivers seat, the positioning differs with each manufacturers and model. In any case that you find the port both under your hood and close to the driver's seat, you know that you have that communication system that is the transition between the OBD I and OBD II systems, some people call it OBD 1.5.
Each of this systems has advantages over the other, taking a look at the first OBD system, the capabilities was a bit restricted,there were fewer sensors and communication protocols which gives a lot less access to every part of the vehicle.
The regulatory intent of OBD-I was to encourage auto manufacturers to design reliable emission control systems that remain effective for the vehicle's "useful life". It started in California, people had to pass these emission test before their vehicles were registered.
OBD 1.5 refers to a partial implementation of OBD-II which General Motors used on some vehicles in 1994 and 1995 but did not call it OBD 1.5, they simply have OBD I and an OBD II section in the manual.
The OBD II is an improvement over the OBD I in both the range of scope and standardization. The OBD II goes into specifics, it also allows for a single device to scan different cars no matter what the connector(DLC) on your car looks like.