Transmission solenoids

[mightymoose_22]

2002 Santa Fe, 2.7 AWD

The transmission has started going into limp mode and causing the check engine light to come on. The codes given are for shift solenoids C and D. There is also the generic Transmission Control Module code.

Limp mode only occurs at higher speeds although shifting feels a little rough at times in lower speeds. If operated in manual mode the vehicle can be driven normally at all speeds without going into limp mode.

Fluid levels are fine.

With limp mode occurring in automatic but not occurring in manual mode, is it more reasonable to believe the solenoids are malfunctioning or the control module itself? I'm inclined to replace the solenoids but find it odd that the vehicle operates normally in manual and would appreciate some input.

Also, can the solenoids be replaced without removing the transmission? It looks like I could get the pan off but am unsure if there is room to get the work done once it is removed. Thanks!