Obd0 in my interpretation is when there is no port of any kind and you have to use a volt meter to check the codes. If I remember right my 83 celica had just a plug that you put a jumper wire in and the cel flashes on the dash it is obd0 I believe.
Ob1 has the port on the firewall that has multiple connectors in it like the e1 and t(te1) which when a jumper is connected the cel flashes on the dash.
Then there is obd1.5. my 96 Dodge neon was ob2 compliant but not fully. Kind hard to explain but basically the computer couldn't give you the same amount of info as a true obd2 vehicle. With my neon and many other chrysler vehicles from like 93-97 they had the old2 plug but also you could read your cel code on the dash with how many times it flashed. you see this sometimes on other manufacturers vehicles during that 3 year period of 94-96 where they were trying to switch over.
Then obviously obd2 has the plug inside the car and gives you diagnostics of the vehicle, with no other way to check the codes other then a scan tool or code reader. Some newer vehicles will read you the number code on the dash also. Only ones I've seen it on is certain cars with a digital odometer
Ob1 has the port on the firewall that has multiple connectors in it like the e1 and t(te1) which when a jumper is connected the cel flashes on the dash.
Then there is obd1.5. my 96 Dodge neon was ob2 compliant but not fully. Kind hard to explain but basically the computer couldn't give you the same amount of info as a true obd2 vehicle. With my neon and many other chrysler vehicles from like 93-97 they had the old2 plug but also you could read your cel code on the dash with how many times it flashed. you see this sometimes on other manufacturers vehicles during that 3 year period of 94-96 where they were trying to switch over.
Then obviously obd2 has the plug inside the car and gives you diagnostics of the vehicle, with no other way to check the codes other then a scan tool or code reader. Some newer vehicles will read you the number code on the dash also. Only ones I've seen it on is certain cars with a digital odometer
