It got warm recently, so turned my AC on, was just blowing hot air, although the compressor was kicking on and off, so I put some Freon in, no change. I could feel heat below the dash that told me hot water was running through the heater core/system. Found a JAG AC web site, (DIY: Diagnose It Yourself - JaguarClimateControl.com) has a procedure for checking the sensors, DCCV, and CCM, oh boy, here we go. Knowing the DCCV can corrode and lock up, I took a shovel handle I had cut off a broken shovel, and poked/banged the DCCV from above several times, just to see what might happen. Drove the car yesterday, and whataya know, the AC is working! No heat below the dash.

 

Result!

 

They stick and get worse, then take out the CCM. Sounds a temporary fix.

 

In my field (aircraft maintenance), the unofficial term for that is "technical tap". Lockheed (giving away my age) issued a procedure to take a mallet and smack the wing upper surface at specific points to shake the fuel quantity probes and dislodge any drops of water that were affecting the indication. Passengers would be staring wide-eyed while you walked along the wing and periodically started wailing with a giant mallet. Pretty much always worked.

Boeing has a similar procedure for the air conditioning packs on certain planes. A compressor/turbine unit would not always spin up properly. Boeing gave very specific instructions about where to hit, and even suggested using a tire chock. Also works like a charm.

Back to your DCCV, I'd suggest planning to change it in the near future. If sticking like that, it is likely to eventually get worse. The 2003+ cars also have a nasty tendency to burn up the control module, too.

 

If you just randomly add Freon you have no idea if the system is full, under full or over full. Vacuum the system down properly and put the factory amount of Freon back in. THEN start your troubleshooting.

Right now you have no idea what is wrong.
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That's true but the AC is working so why do anything?