The PMV I got from the Auto Wrecker was bad, too. Fortunately, I can get a refund when I give them their part back (we have a great yard here.....they're on the forum!). What this means is I have to buy the new PMV from www.gmpartsdirect.com
, install it, and THEN take the PMV back to the wrecker for a refund. We live and learn. The new part is only $19 US more than the used one. At least for the ABS PMV, I strongly encourage new part replacement. The worst thing for these assemblies is sitting around with static brake fluid in them. It erodes the coils on the isolation valves.
What would be nice? Another way to read the codes in an ABS system other than taking it to the dealer, or at the very least, a pinout of the PMV so you could check it with an ohmmeter........oh, winning the lottery would be nice, too