Where is the cranckshaft position sensor onGM 3.1 liter engine?

The crankshaft position sensor (CKP sensor) on a GM 3.1L engine is typically located on the passenger side of the engine block, near the bottom of the engine, close to the crankshaft pulley. It's often mounted in a bracket or directly to the engine block itself.

However, the exact location can vary slightly depending on the specific year and model of the vehicle. A repair manual specific to your vehicle's year and model will give you the most precise location. You can also use online diagrams or search for images of your specific engine to get a visual reference.