Awhile back I noticed my truck was shifting hard so I brought it into my high school mechanics class. I read up on it and then did diagnostics. The run threw a code that a shift solenoid had busted. I read a bit more and figured there may be moisture in the wiring connecter. I took off the connector cleaned it with brake clean, sprayed some air in it to dry it up then added some contact grease. After that we deleted the code and the truck shifts better than before!! Plus it never cost me a dime!