Have the modules scanned for any fault codes
Glenn Beasley Chrysler Tech
Try testing the pressure cap. this will cause a boil-over which will cause an overheat. If you don't have the tool, try this link. I get my tools from here.http://www.aktoolsandequipment.com/index.asp?PageAction=VIEWPROD&ProdID=27659or it may be cheaper to get it tested by a shop,good luck, repost with results.