I think Chrysler has admitted that all 2009 to 2014 5.7 Hemis with MDS have a defective all-plastic shoe in the timing chain tensioner that seems to wear excessively the more MDS mode is used.
When the plastic shoes goes bad, it breaks the timing chain. When the chain breaks apparently the pcm quickly stops the ignition which reduces damage.
Must have been the same design team Harley had on the Twin Cam engines......