i know they are for a trans fluid pressure sensor. is this a big deal and anyone have an idea what the cost is to have it fixed?

 

Yes,P0876 is the under drive pressure switch. You have a 45RFE trans and the solenoid pack will have to be changed. The pack runs somewhere around 200 and then the labor to pull the valve body and put the new pack on.Plus fluid and filter.Total guessing somewhere around 350 to 400 dollars.

 

Cheaper than a complete rebuild!!

 

Hey Transguy37, sorry for digging up such an old post but I'm having the same PO876 code but on a 45RFE tranny. Is the underdrive pressure switch on the outside lower back right of this transmission? I've replaced this part #4799758AD with no luck. Going to pull the speed sensors out now to check.