ODB1 or ODB2?

[ADiamond75]

Ok, so I have a 95 240sx and have had a real hard time determing if it is ODB1 or ODB2.

SOMEONE TELL ME A DEFINATIVE WAY TO TELL THEM APART.

Here are some of my delemas

The wiring harness on the ECU doesn't match the diagram AEM gave me for the ODB1 or the ODB2 but seems to be closer to ODB1

Car says it's ODB2 under the hood

Car has never been able to be hooked up to ODB2 scanner according to all emmissions testing

Car has rear O2 sensor.

HELP!!!!!!!!!!!!!

Oh, and I did search and it didn't turn up anything for me

[VeloceDrift]

Its an ODB1 because ODB2 didnt come out untill like 97 in any car

[ADiamond75]

actually there are two different ECU's for the 95 .... then the 96, 97 and 98 have the same ECU

the question is how do I determine which ECU my 95 has

[VeloceDrift]

i looked it up and nissan did not start using OBD2 until 1996 so i guess it is possible if it were manufactured in late 95'. you should just take it to someone with an OBD2 reader and plug it in.. that will tell you for sure.

[dkdeleon68]

i looked it up and nissan did not start using OBD2 until 1996 so i guess it is possible if it were manufactured in late 95'. you should just take it to someone with an OBD2 reader and plug it in.. that will tell you for sure.

That is wrong info, Nissan started Obd2 in late 1995 that is why there are two different ECU's for that year other than M/A ECU.if you have a second o2 sensor chances are you have obd2.

[VeloceDrift]

Gotcha yeah the sources i looked at both said nissan started in 96.

[ADiamond75]

Gotcha yeah the sources i looked at both said nissan started in 96.

There are in fact two different ECU's for 95.

On a second note, besides the ODBII plug .. having someone plug into it and the second o2 sensor (which is there) is there any other way to tell ?

What I really need is someone with ODB1 95 ecu to send me the part number and someone with the ODBII 95 ecu to do the same. Then I will go look at it and figure it out.

[ADiamond75]

That is wrong info, Nissan started Obd2 in late 1995 that is why there are two different ECU's for that year other than M/A ECU.if you have a second o2 sensor chances are you have obd2.

OK, here is some more info to ponder over .. someone give me a definative answer .....

1.) my ecu part number (looked up by VIN) is 23710-70F012.) My manufacture date is 9/943.) The ECU for a 95 manufactured in 8/95 is 23710-72F02

Talked with a nissan parts guy at Pinnacle and they can't tell if one is ODB1 or ODB2 and they wouldn't stay on the line long enought to tell me if there were any other variations during that year.

At this point I'm gonna guess it's ODB1 but that second O2 sensor and all those tags under the hood staying it's ODB2 are really making me nervous.

HELP !!!!!!!!!!!!!!!!!!!1

[480sx]

96 was when the US govt required all cars to be OBD2 compliant. Apparently nissan did this a little earlier. For the longest time i thought i had a 96 because of OBD2(and because the moron who sold it to me called it a 96) but actually its a late model 95 with OBD2.

It sounds like you have an OBD2 like mine, but thats weird that you cant connect to the computer. I mean, if your car has the obd2 port i would assume that its obd2, and your connector/wiring is broken or something. Whats the production date on your car? That will tell you too. I think mine is 8/95, so if your car is that or later, it would be OBD2.

[ADiamond75]

production date it 9/94