PCM Question - 3.1 GM - 1995 - HELP!!! **SORRY IF REPOST**

[Kurek, Larry]

All:

Couple of quick questions on this PCM (I do not have the number with me...).
It is in a 1995 Chevy Lumina with the 3.1. It is mounted under the hood, and
appears to be a flash programmed PCM. Here are my questions:

1) Got a spare from the boneyard. However, it is from a 1994 GrandAm 3.1.
Engine ran fine, but no cruise control. The Service number is the same,
although the calibration is different. Is cruise a programmed function?

2) The only thing that doesn't work in this car is the A/C. I have checked
all the circuits up to and away from the PCM. Relay is fine, PCM is getting
an A/C request, I jump the high pressure switch and the fans kick on, I jump
the relay and the compressor kicks on, etc. HOWEVER...the PCM does not seem
to want to turn the compressor on itself. The pin that is the A/C Compressor
relay control (at the relay), is supposed to be +B without A/C request, and
grounded with. I measured it as open...neither ground or +B, in both modes.
This is the same on both PCM's...so what is with that? Any ideas?

3) Since this is a 1995 car, I assume this is OBDI. It has the good old 16
pin connector of old. However, it only has two pins used...the serial data
pin and ground. There is no provision to put it into service mode by jumping
pins. Also, although Diacom claims to support this year/engine, I cannot
link my PC to the PCM. What is with this? I did hook a scope up to the
serial line and it is dumping nice data (Square waveform...), so I know the
PCM is communicating. 

Any help appreciated.....

Thanks!!!
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