Just had this issue with my 2008 Honda Fit; error code P0847 with "D" light flashing. The current Honda part number is 28600-RPC-004 (Automatic Transmission Pressure Switch) All fixed.
Thanks to all that contributed to this thread!
My Fit is happy again!

 

hello from Puerto Rico. I am new to the forum although I have been reading the posts for a long time, I have an uncomfortable problem, if someone has passed him on about this code, first he had the code p0848, I bought the sensor and I also bought the oil filter (both on ebay) Before changing the parts, the D would blink, if I turned off the fit the light would return to normal until it failed a few miles, after changing the sensor the fit improved a lot, but now comes the problem, I drove a few miles and everything was fine. At the moment the D started to flash again and it no longer goes off even if I turn off the fit and turn it on again, so now it gives me the code p0847 .. the oil level is fine .. has someone else happened to this?