PIC UART to work with USART
Things to check / try:

Make sure you have the right baud rate set for your clock speed.  The calculation is made somewhat more tricky by the newer 16-bit baud rate generator option.

Make sure you are actually running at the clock speed you are expecting to be running at.

Check you have the clock polarity set right - try different settings:



bit 4 SCKP: Synchronous Clock Polarity Select bit

Asynchronous mode:


1 = Transmit inverted data to the TX/CK pin




0 = Transmit non-inverted data to the TX/CK pin




There is a similar setting for the receive clock somewhere, but I can't find it at the moment.