1995 - 1996 OBDI OBD II PCM Question

[iwin12]

Can I swap a 1996 PCM into my 1995 SSE to make it true OBDII? I would guess I will need to add wiring/O2bypass chip for the downstream O2 sensor that is not on the 1995's.

Thanks in aadvance. Has anyone else thought of or done this?

David

[00Beast]

It's possible, but it's a lot more work than just swapping the PCM. You basically have to create a new harness.

[iwin12]

Any tips on successfuly scanning a 1995 SSE? I have read where you can not even get blink codes and OBDII scanners match the plug but will not read codes.

Any help/suggestions would be great.

[MattStrike]

You are dealing with what we call OBD 1.5, which is an OBD 1 computer without the SES flash ability that has a OBD2 plug. IIRC the OBD port on these has the data transmit on a different pin than the OBD2, which is why the scanner doesn't work. But it's still OBD 1. It doesn't have a way to read the codes other than the appropriate scanner or a pc-based scan tool. I don't know which scanners specifically work with OBD 1.5, I use a PC-based tool.

[iwin12]

Thanks mattstrike. What kind of PC based tool and how much are they? Sounds like would be better than getting an OBDI scanner.
Thanks

[MattStrike]

I only know of one that supports OBD 1.5, but others may know of more. I think there was a handheld snap-on scanner that used to be available to read the OBD 1.5, but you asked about PC-based:

I use EFILive V4. You will have to make or buy a cable to interface with the car, and for OBD 1.5 you'll have to make an adapter. I bought a cheap ebay OBD-2 'cable' (just a cable, nothing more) and cut the end off, used a DMM to identify which wire goes to which pin, then used a junkyard OBD-1 port to plug into the OBD-1 cable we made (ours uses the COM port, but USB cables are available).

http://www.aldlcable.com/ - info on the OBD-1 cable
IFILive V4 - pricing on the EFILive V4 software license

The only caveat is that EFILive doesn't ship with a 'profile' specifically for our cars. There is a list of the 'datastreams' that details the required info on how to create said profile, but it is still time-consuming. I have the files for the '93, but they differ from the '94-'95. I have the '94 C/W-body files somewhere as well (Park Ave had the OBD-2 port, Regal on the OBD-1 port, same 'profile'). They have a dedicated forum for the V4 program, with a generally knowledgeable and helpful moderator; but I can share what I have for the '94 as a starting point.

[iwin12]

Thanks, I will look at that info.