Okey Dokey.

QDM...there are three different codes. If you knew which one it would help greatly.

Think you said 1... but part of the diagnostics say monitor voltage at the pcm connections and wiggle them and see if code sets. if so clean and fix. If the condition keeps recurring w/o any apparent connector problem replace pcm.

P1640 aka P0640 Code will set when engine is running, PCM detect improper voltage on a QDM#1 circuit for 5 seconds or the computer is generally messing with you.
Boost Control Solenoid
Evap Purge Valve
TCC Apply Soleniod

P1650 or P0650
QDM#2
Shift Sol A
**** Sol B
TCC PWM Sol
TCC Apply Sol

P1670 or P0670
AC Relay
Service engine soon light
Low speed cooling fan
High speed cooling fan

Good luck...at least it sounds like yours is totally messed up and can only get better.

I believe I found the problem. It seems to be the Boost Control Solenoid. My brother has a 92 SSEi and I did some swapping and that solenoid appears to be part of my problem. I'm not sure if it'* the solution to all my problems though. Anyways I'm having trouble finding this part. I called the dealer and he gave me part #12353309. I just want to make sure the solenoid comes with this part.

That appears to come with everything you need. According to GMPD it'* sold as a "Kit" whatever maybe in that.

have you treid a different pcm? Autozone is known for selling bad parts around here. I had the same problem though I have just an SE, and I still had QDM codes, and it was driving me crazy I found it to be the computer heres the link where I posted my fix http://www.bonnevilleclub.com/forum/...ggle&start=125
and be sure to DISCONNECT the battery when you unplug/plug in the pcm, or you could fry it before you even know it

I thought I posted more about my QDM1 fault but I guess not, but anyway when I battled my QDM fault I thought it was the purge cannister too, I even replaced it, no fix, but the symtoms where; no a/c, no cruise, weird shifting, tcc codes, blowing fuses, and ofcourse the check engine light, one more thing to add about your computer swap, check the fuse panel by the computer, it should be right in the kick panel, the fuse labeled Misc/Eng its a 15A it could be fried, mine kept doing that, and depending on the year of your bonni, the QDM1 may not control the TCC in 93 and below it does, 94 and up it does not..just a lil FYI

Follow up. QDM-1 Failure solved. The cause was a Bad Boost Control Solenoid.

Awesome..so all your problems were caused by a bad boost soloniod...

Hmmm I'll be looking at my 95 soon...cause I think I still have one.

I'm betting that BCS had a short internally, effectively loading the QDM circuit in the PCM. Normally a BCS failure won't take out the other functions of the QDM.

Great find.