I've been having this problem on my 02 Silverado for about 10 years. A few years ago, I bypassed the ignition cylinder by hard wiring in some resistors,and "teaching" them to the BCM; this worked fine for about 2 years until the unit would randomly drop the code. I thought I had the hot lick by getting another BCM off eBay for $20 shipped. Installed the new BCM, and relearned via the 10 min. procedure 5x to no avail- no start. I was talking to a high performance friend and he found the stupidest fix I could ever dream of on a software website. The post included the following procedure: Get in the car, shut the door, ignition on, ignition off, window down, window up, lock, unlock... The blasted thing started immediately! I was flabbergasted to say the least. On a sidebar: I am playing with a 2002 3800 Series II v6 transplant into my 85 Pontiac Bonneville. The engine came from an 02 Firebird equipped with what I now know as Passkey 2 or 3 (resistor in key, to BCM, to PCM). I have now learned that the PCM...