4L80E shifts hard, your thoughts on the fix?

[Old Yeller 1970]

I have a '06 3500 van with 60k mi on it. Recently it's begun shifting hard and the check engine light came on. I took it by Autozone and found a P0894 code.
The printout reads: Transmission component slipping. The ECM has detected that the TCC slip speed is greater then expected. Probable cause.
1. Low transmission fluid level (It's OK)
2. Contaminated transmission fluid (I bought a filter and 8 quarts of Dexron IV)
3. Failed TCC soleniod. (Neither the Autozone guys or myself -till I got home- knew what a TCC (Torque Converter Clutch) solenoid was so I didn't get one yet)
4. Poor electrical connection. (I crawled under and everything appears to connected OK)

Since TCC solenoids are relatively cheap, esp compared to the cost of trany fluid, I figure to put one in. Under normal circumstances the fluid should be replaced every 100k mi and I doubt if it's contaminated enough to cause the problems. But I would welcome others experiences.

If I buy a new TCC solenoid, will it be obvious where the original one is once the pan is dropped or am I going to have to dig for it?