tr Volvo 850 Transmission TCU TCM Up for sale is a Working, in excellent condition Volvo 850 TCU (transmission controller). Part number-- T93250541 / P 3545864 . This unit is original for most 95 850 non turbos. This came out of a 1995 volvo 850. This unit offers a 30 day functionality warranty. This may fit other years too, as always with this type of component your best bet is to match the part number to the one on your original TCU. A faulty TCU can mimic the symptoms of a bad transmission. Though generally fairly reliable, it is not uncommon for this to be a non diagnosed problem that gets all the way to a transmission replacement, which will not cure the symptoms. The TCU, Usually almost as expensive as the transmission iteslf, is now available here for pennies on the dollar. try this first! Check the part number off your original, I have many of these.If your car does not have issues but you intend to keep it a while, I recommend our customers keep an extra TCU in the trunk. These units now have to be special ordered from most dealers new for big $$ (often times over $1000!). Even now finding a good one second hand is getting to be quite difficult as these cars get older. Most Volvo 850 ECU / TCU's are located in "the black box" on the right side of the engine bay. They are easy to access, all you need is a 8MM wrench to remove the lid, once inside they have quick connectors and will slide right out!