2007 Ford Taurus Big Problems with PCM and Overheated Tauru

I've had problems with the 2007 Taurus since I made the mistake of buying it from a Nissan dealer. I didn't trust the dealer and brought it to Ford who fixed the ignition key lock (car wouldn't start) and the main gear shift under warranty. I tried to cancel the extended warranty from Nissan but had problems with them doing it.

Two months passed, the car started to shutdown while driving it and then overheated the following week. I immediately pulled over, let the car cool down and put my antifreeze in it.

I brought it back to Ford and decide to use the stupid extended warranty from Nissan. Ford said after $350 that it's an electrical short and needed another $500 to keep looking. Nissan extended warranty service said "we don't cover Electrical problems", so no deductible, pay it yourself.

The car sat in my driveway for 3 months, then I brought the car back to Ford and now they are telling me that the the cooling fans were not turning and that the PCM is shot (main computer in the car?) And the wires in the main harness are fused together. Minimum $4000.00!

Nissan extended warranty doesn't mention anything about covering a PCM, just an ECM. HELP! This car has been a lemon from the get-go. Isn't the PCM covered as part of the powertrain? I've had the car for about 2 years and haven't driven it all that much since it's always in the shop.

I am about to call Nissan quality care who I have a feeling will tell me to get lost.

Please tell me what I can do and maybe a bit about this PCM and ECM, Etc.

thank you so much
Jay