pmihaltian

What model year Corvette did they change from OBD-I to OBD-II ?

aboatguy

Corvette switched to OBDII for Model Year 1996

PLRX

techvette

However, 1995 models were wired for OBD II, it just wasn't hooked up.

pmihaltian

Thanks guys.

Solderhead

Hi all, and sorry to resurrect this thread but I'm curious about this. The 1994 and 1995 models both used a PCM, and I'm wondering, is what you say about the '95 model also true for the '94? If not, do you know of the major differences?

STL94LT1

There are no fifferences in the 94 and 95 models, they both use the same OBDI PCM. There may be slight differences in the tune.

pcolt94

Bt let me just add that if you connect a 16 pin OBD2 code reader the try to see the OBD2 codes on my 94 (or 95), it will not even communicate (which is a given). But when I connect my Tech1 and look at the DTC codes (for OBD1), after it shows me the codes it goes to OBD2 codes. It always says "no OBD2 codes". So never having an OBD2 code, I really don’t know if it is actually working properly, or it always says that regardless all the time.

I hope to really never have a OBD2 code which would make me real happy.

etteroc27

The same code scanner that works on my 1997 chev pu also works on my 95 corvette. It will communicate with the car as to codes or engine information. The plug is the same. I can scan the engine functions and recieve trouble codes on it, both the code and a brief description.
This scanner also works with my 05 Ford pu. I don't know a whole lot about obd1 or obd11, but I do know this actron scanner works on my car.

Solderhead

Thank you all for the replies. So here's my next question, if the setup for OBD II was technically "there" in the '94-'95 models, could switching to a true OBD II PCM really be as simple as getting a PCM from a '96, then getting a calibration flashed (say from '96 again) and installing it in the vehicle?

STL94LT1

The 1996 OBDII PCM monitors the crank position and rear o2 sensors. These could be tuned out, but I really see no reason to run an OBDII PCM in a 94/95. I'm not sure but the PCM and CCM may also have issues communicating.

Solderhead

Thanks for the info! I was just thinking about the "true" OBD II and was wondering if it would offer any perks as far as drivability and easier diagnostics.

STL94LT1

The main difference is the OBDII systems does a better job at monitoring emissions, no difference in driveability.

MissileDoc

http://www.amazon.com/Automotive-Dia.../dp/0760328005

This is a good book that describes the difference between OBD-I and OBD-II systems and gives great advice in the use of code reader and scan tools. I learned quite a bit about the function of emissions systems and how to troublrshoot and repair them from this publication.

Solderhead

Well after your input I think I may just skip the project I had in mind and save some dollars in the process. Thank you, and also thanks for the link to the book as well, I may have to pick that up.