It was a 2007 Honda Civic, the 3rd clutch pressure switch measures fluid pressure. P0847 was the code. This means the sensor was sending a voltage value below the acceptable range.

The car shifted fine, the fluid was at the proper level, and there were no noticeable driving issues. This would also not continuously read a low voltage reading while changing gears. This led me to believe it's the sensor, which is very inexpensive and easy to fix. The car is working perfectly now.