I have a 2006 Silverado 1500 vortex max. Gen 3 lq9 6.0. I have a spark issue and looking to get ideas of what to check. All 8 cylinders have no spark. It has power to the spark plugs but not enough to jump the gap. I have swapped the pcm from another truck and did a key relearn. I have swapped coils. I have replaced the camshaft position sensor and crank shaft position sensor. I have checked the grounds from the battery to the block and from the block to the body and the ground for the coils to the block. It has 11 volts at the plug going into the coil. I have had an inline spark plug tester hooked up and it barely lights up the tester. I have taken a spark plug out and held it to the block and it will not jump the gap. Any help will be appreciated.

 

Bad IGN1 / IGN A relay or melted fuse-block terminal feeding the coils would be among the simplest things to check that are likely culprits.