Where is crank sensor on 99 jeep 4.0 grand Cherokee?

The crankshaft position sensor (CKP sensor) on a 1999 Jeep Grand Cherokee 4.0L is located on the passenger side of the engine block, near the bellhousing. It's usually mounted fairly low down and may be somewhat difficult to access. You'll likely need to work underneath the vehicle for the best view and access.

Important Note: While the general location is consistent, the exact position might vary slightly depending on the specific engine configuration. A repair manual specific to your vehicle's year and model is highly recommended for precise location and removal/installation instructions. Pictures in a repair manual will be invaluable.