the code reads: Open in second clutch Transmission fluid pression switch circuit or Second clutch Transmission Fluid Pressure Switch stuck OFF, is this a fix that must be fixed if the The car is Driven for several hours at a time?
Trouble code P0843 pops up quite frequently on vehicles such as your Honda CR-V. The 2nd clutch transmission pressure switch is installed in the hydraulic pressure circuit to the 2nd clutch.
The Powertrain Control Module (PCM) uses this information to determine when the 2nd clutch is being applied. While this code can indicate an internal transmission problem, typically just replacing the switch is all that is needed. The switch is located on outside of the transmission.
I recommend having a professional, such as one from YourMechanic, diagnose this trouble code further and repair this problem accurately for you.