compadibility of pcm's?
 

I know this is my first post. I have been lurking around here for a while in an attempt to educate myself. Time to ask the pros!

Now here is the story. Bought an LT1, I was told it came from a 1997 SS Camaro. It came w/ an extra harness and the computer was plugged in to that harness when I bought it. The second harness is out of a big car and I believe is II.

I helped a friend rewire it for stand alone. We started it on the engine stand and it died after 3 seconds. My buddy had sent the pcm off to Jesse Bubb to remove the Vats. Jesse told us to hook up the mass air flow sensor to prevent the dying, I have tried two MAF's and same results. We wired in the OBD II plug today and tried a scanner for codes. The scanner says it can't communicate w/ the ecm.

Sorry for the history, but I'm sure somebody will ask. So here is my question. After researching, I believe the engine & harness are OBDI and the computer is OBDII. (we have the diag. port wired for the OBDII) How can I tell which is which?

The only difference I could find in telling the harness' apart was the OBDI didn't have a tan wire from the blue pcm plug #30 to the #9 of the diag plug. The OBDII harness has that wire and cat down stream O2 sensors.

if it helps, here are the #'s from the pcm serv. no 16181333 BJSP

and *86BJSPK0324103P8*

ANY HELP WOULD BE REALLY APPRECIATED. Thanks, Stan

That PCM is a OBD1 out of a Vette, When you switch from OBD II to OBD I there is no wiring to change out. You can still use the same port, same wires, My customers do this all the time..

I think the only thing that is required in this instance is the knock sensor needs to be OBDI.

Yes, You are correct, the knock sensor on the block is of different ohms and will throw an SES light, there is also a resistor mod that you can do

On my 97 T/A I just bought an ECM for a 95 Z and plugged it in, using a propper Knock module in the ECM. The knock sensor on the block is still a 97.
I later (after tuning the crap out of it with CATS) tuned out the knock sensors effect on the tune , but I left the circuit there so I could read knock with a scanner.

Thanks for the input guys, I'm going to the shop here shortly.......I'll keep you posted.

Ok....deep breath in..deep breath out.....I'm ready. Here is the current situation. I borrowed a ecm from a guy in town. Starts but dies in 1 second verses my ecm at 3 seconds. Removed the OBDII diag. plug and installed a OBDI type plug. Scanner still says vehicle not responding.

Can someone please verify I have the diag plug wired correctly. A= ground, E= batt. hot, M=29 or 30 in the blue ecm connection. (I have tried both locations).