I'm sure someone else has had this problem but I apparently haven't found that thread yet...so my 2000 Silverado 5.3 has basically been in pieces but in project mode for 2 years...the whole time still starts and runs...now all of a sudden when you start it it immediately dies...throws code p1626, no communication from BCM to PCM...checked all the wiring and plugs, no issues...reprogrammed passlock, still nothing...installed new (refurbed) BCM and PCM, still nothing...replaced ignition switch and passlock block, reprogrammed again, still no luck...I'm at a loss at this point and really don't want to have to trailer it to the stealership. I'm sure its something very stupid and simple...

PLEASE HELP...if anybody has any possible fixes or info please let me know...THANKS IN ADVANCE!