Had similar thing happen in brothers truck. Is key stuck and doesn't go in park? Try this may help you. We took his brand new truck out on first trip and had same problem you described. Used thin torx screwdriver to depress override. Hope this helps. Worked fine after that
Page 307 What to do in emergencies
http://www.ramtrucks.com/download/pdf/manuals/2014-RAM_ProMaster-OM-3rd.pdfSHIFT LEVER OVERRIDE
If a malfunction occurs and the shift lever cannot be moved out of the PARK position, you can use the following procedure to temporarily move the shift lever:
1. Turn the engine off.
2. Firmly apply the parking brake.
3. Using a small screwdriver or similar tool, remove the shift lever override access cover which is located below the shift lever.
4. Press and maintain firm pressure on the brake pedal.
5. Insert the screwdriver or similar tool into the access port, and push and hold the override release lever forward.
6. Move the shift lever to the NEUTRAL position. 7. The vehicle may then be started in NEUTRAL. 8. Reinstall the shift lever override access cover.