I had the same problem on my 1999 VW Jetta. Cost me $600 to replace an $85 sensor,most of it diagnostics.
Yup, but on the jeep is a 30-50 dollar sensor held on by 2 10mm head bolts. very easy to replace.
when ever one came in the shop doing what they describe with out codes we always put a crank sensor in first. 99% of the time it’d fix it and the sensor was cheaper than the diagnostics.