CAGS, otherwise known as skip shift, is a system fitted to certain GM vehicles that locks out second and third gears under a specific set of conditions, forcing a shift from first to fourth. Shifting from first to fourth while casually cruising generally uses less fuel than shifting from 1-2-3-4, so the system locks out second and third to promote better fuel economy…and to help vehicles dodge the gas guzzler tax. For my purposes, this system is dead weight. I deleted it and removed the associated wires from the engine harness. The steps below tell you how to turn the solenoid into a plug.
Locate the CAGS solenoid. It protrudes from the drivers side of the transmission. Mine is sitting on the table of a chop saw, an indicator of what’s to come.
Cut the solenoid in two. I made my cut in the center of the hexagonal section. This is a good time to learn how a solenoid works, if you’re curious.
Remove the copper and other loose material from the base of the solenoid. You’ll be left with a pin sticking up on the inside. I pushed that pin down, which caused a larger diameter pin to protrude from the bottom of the solenoid, and used vice grips to hold the larger pin out. When you do that, you’ll be left with a flat surface on the inside to weld on. Weld over the small pin on the inside to keep it down and to seal the gap, making what was a solenoid into a plug. The larger pin will still be exposed after you weld. Remove that with a cutoff wheel.
Finally, I cleaned out the inside of the solenoid with some acetone and sprayed it with self-etching primer to prevent rust. Once dry, reinstall the plug and delete the emergent error code from the PCM.