Crankshaft Position Sensor problems of the 2004 Jeep Wrangler

I own a 2004 Jeep Wrangler with a 4. 0 I-6 engine. Within the past 2 weeks, the vehicle has stalled on the highway 3 different times. The following applies to all 3 incidents. . . Once I got the vehicle over to the shoulder and stopped, the engine would not restart. The vehicle was towed to a dealer where the crankshaft position sensor was diagnosed as faulty and thus replaced. The crankshaft position sensor was replaced three times. All 3 incidents of failure have occurred at highway speeds. This raises my safety concern since I can not accelerate and safely pull to the shoulder, especially when the surrounding vehicles are at highway speeds. The incident date posted was the date of the third and most recent incident the second incident occurred on may 23, 2004 and the first incident occurred on may 18, 2004.