NHTSA Complaint #11454554 — 2018 RAM 1500

while driving on the highway with cruise control engaged at 60 mph there was a loud clunk sound and the truck immediately decelerated. The cruise control had disengaged and the truck seemed to go into limp home mode and the check engine light came on. I pulled to the side of the road and shut the engine off. I looked under the truck to see if I had run over something and checked the drive line for damage but found none. Restarting the engine took considerably more crank time than normal. While driving home the truck would not accelerate normally and top speed uphill was 19-23 mph depending on the climb with rpm around 3000 before what felt like fuel cut off and immediate deceleration until rpm was dropped to around 2000. The 5 hour trip home turned into an 8 hour trip. The check engine DTC is P0336 (crank position sensor A circuit range/performance). There is a recall W58 (20V475000) for software update for loss of crankshaft position sensor signal. This update substitutes the camshaft position sensor signal for the lost crankshaft signal. There is a known defect with the tone ring on the 3.0 eco diesel. The magnetic material on the tone ring delaminates. The software update does not fix the loss of crankshaft signal. The engine now has excessive crank time before starting. There is an a noticeable aceleration lag and the truck struggles on uphill grades. The cruise control is now inoperable with the crank signal DTC is permanent until the tone ring is replaced. My repair shop checked for parts avaiability and found dodge has 22,000 in stock which leads me to believe that they not only know about the problem but also know the only true fix is to replace the failed tone ring. The truck is unsafe to drive until the failed tone ring is replaced.