ob2 ecu codes?

[gotspeed]

i read the thread about OBD1 codes which are 93-95 J30 and i read about the OBD2 codes for 95-97 the first codes said they could be read off of the ecu, but for the OBD2 codes it didnt mention that codes can be retrieved from the ecu. My question is can the codes be read from the Ecu on the OBD2 cars like my 97 J30. I have found out how to access the ecu on my car but i dont know how to take it out, i do see a big screw that looks like its holding down the wire harness, Is that the screw that frees the whole thing or are there others?
Modified by gotspeed at 10:09 PM 5/24/2007

[gr8scott72]

There is a sticky at the top of the forum that answers your question. Have you read it?

quoted straight from said sticky:

This article relates to 1995-1997 J30/J30t's with OBD2.An OBD2 scan tool is required to retrieve codes. The consult port for the OBD2 scan tool is located under the lower portion of the instrument panel.

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That being said, some places like Auto Zone will scan your car for free and give you the code.

[gotspeed]

i did read the article above, but i asked my question in case the author forgot to say that the codes could be directly read on the ecu ( like the blinking led on obd1 cars) i dont have a consult tool or whatever its called and it was to late to make it to Autozone so i was trying to get answers at that time. and according to that article obd1 cars didnt need a tool to access the codes you can look directly at the ecu, So there in turn was my question. Could the codes be read off of obd2 cars, as in looking at the led light on the ecu? So i am under the impression that my car doesnt have a led light to look at on my ecu , but i have to either get a tool or take it to Autozone right?

[gr8scott72]

i have to either get a tool or take it to Autozone right?

You got it.

[driverdriver]

All obd2 cars regardless of make require a scan tool to read codes. There is no other way to retrieve them.

[gotspeed]

now my next question issssss, If the check engine light isnt on does that mean there are no codes to be retrieved? I remember somebody saying that they had codes but the check engine light wasnt on. my car is getting bad gas milage and i was wondering about my 02 sensors.

[gr8scott72]

How bad is bad gas mileage? What mpg are you getting?

[gotspeed]

i dont have numbers yet but i just realized that my car ususally goes over a week on a full tank, and now i have to fill it up like every five days. I am going to get more technical about it on my next fill up. But i do know that its horrible. and like i said check engine is not on. I plan to get a fuel pressure test done soon.