AlwaysWave

I did a search but can't find anything specific enough. The OBDI on our 95 appears to have some fault or another. I was wondering if it was possible and reasonable to install an OBDII??? All the other cars (except our 72) uses the OBDII so maybe I won't need two different sets of scan tools. Bear in mind I'm more of a carburator guy than dealing with engine management systems.

bogus

that's much like putting in dentures to fix a cavity.

I would suggest not doing it. get a new/used OBDI ECU and be done with it.

MikeC4

This would not be just a simple ECM swap. The OBDII has more functions like "crank position sensor", "serial data", "rear O2 sensor data", and a few others, which the OBDI does not have.
Chances are you would need a complete new wiring harness to acommate an OBDII ECM. Sounds like a nightmare......

90Z51

You'd be better off with just fixng the OBD I system you hve. A while back I had an M3, the big thing in the M3 community was swapping their OBD II system to OBD I. I can't imagine the nightmare of going from I TO II though.

pcolt94

Even though in the 94 and 95 years, the computer software was moving to the OBDII system requirements. In order to do a conversion, all three computers, CCM, PCM and Brake would have to talk the same language and have all error codes incorporated in them as well as the internal and external communications. This would also have to involve different wiring harness configurations and inputs. Seems like it would be a near un-feasible task and project to get it as right as a 96 would be with its OBDII.

This is just my un-tried opinion of this project.

Perhaps your fault with your OBDI system can be fixed (if we knew what it was) which would alleviate the problem.

It might be almost easer just to trade in on a 96 and up if its that important to you.

AlwaysWave

Thanks guys. Like I said, I'm not much into the CCM, PCM, etc. My mechanic said the OBDI was at fault, but then again, he didn't answer all my questions, so maybe his diagnosis is incorrect.

I'll get all the "fault" info again and post to you what that is.

Good to see ya Andy.

bogus

Rudy! What up? Hard to beleive it's been 5 years... wow...

Your mechanic is a moron. You can't just say, "the ODBI is at fault." It's like saying you have a head ache, and your body is at fault.

It sounds to me like you need a better mechanic.

MikeC4

On your '95, you can pull the error codes yourself using the "Paper Clip" method. Short A & B together if you have 12pin connector, or 4 & 12 if you have the 16 pin OBDII style connector(but it is still OBDI).

http://www.obd1.com/

http://www.troublecodes.net/GM/

pcolt94

I guess what’s confusing me is that I thought the OBDI system would not operate correctly or show any error codes. Perhaps I took it the wrong way. Or is it the case where you have a properly operating OBDI system and there is an error code or fault.

If the 95 is like my 94, you would connect 4 & 12 as said. After connecting turn key to on but don’t start the engine. The speedometer area will start displaying the error codes in each module. Module 1 is CCM, 4 is PCM and 9 the brake module. It will cycle thru automatically, if no numbers are displayed there are no codes. A C12 in module 1 indicates there are no codes and the system is working. A “C” associated with a number indicates a current code and an “H” indicates a historic code. It’s a great on board system and will tell you most everything that a scanner will.

You have to watch for the module number being displayed and relate it to the error code because the numbers can be the same. Here is a link for the PCM module 4.

http://www.corvettedoctor.com/1994_96_DTC_Codes.html

If you have error codes in other modules the Forum can tell you when you post it.

There is more information but see how you make out getting this far and then it can be picked up from there. Would still like to know what your original symptoms are?