Did you ever get this resolved? I am having same issue on an 05 Dodge 3500 diesel. For some reason it wants a pin to change the vin after PCM replacement. Done 03 Jeeps without needing a pin. Pulled skim to read eeprom and the eeprom number is not listed in the menu for reading pin disassembled. Even called Chrysler to get the pin and the IM 608 says it is not valid. Doesn't seem to be much support on these forums, do you know of another site for support?

 Make sure the ignition is on with a plain metal key. Select Read Pin, Wait 3-5 minutes. Then insert an unprogrammed transponder key and turn on when Prompted. Wait another 3 to 5 minutes and the code should be displayed. Hope this helps for future reference. Good luck. 

The 04/07 caravan pin cannot be read diagnosticly.... Obtain it from the dealer, NASTF,
or 3rd party supplier.

Solución? Help

You have to manually get it