I am a tech and have never used a forum before but this car has been here 2 weeks now and has me stumped. We have an 05 Monte Carlo 3.8 Supercharged that got brought in for a random stall which now had become a crank no start. Has a new ignition module(We have tried 3 of them now.) I have no spark and no crank signal. Have constant 12v being fed through the pink wire into the ICM but am only getting .8V to the 12v line on the crank sensor unplugged. This car does have a tune and we tried a computer and reflashed it still no help. Found multiple bad wires in the harness from icm to crank and cam so we replaced the whole harness, still no change. Strange thing that happened was when checking the crank at one time I had the all the right voltage to the crank but car would not start. I then realised that I had forgotten to re hook up the main grounds on the tranny before cranking it. Hooked them back up and right back down to .8volts. Checked the computer grounds for short to power and they tested good. I am a flat rate tech and have way too much time into this thing for what I am getting in diagnostics so just trying to branch out in hopes someone else has ran into this. WORTH MENTIONING THIS CAR DOES HAVE A TUNE AND MANY AFTERMARKET UPGRADES BUT NO SECURITY LIGHT OR AFTERMARKET WIRING.