My truck:
1990 F150 Custom / 4.9 liter I6 300 / 4 speed with OD manual transmission / 4x4 / long bed.

The issue:
I bought this truck about 3 months ago and just learned the the ECU that is in the truck was replaced by the wrong one (FOAF-14A459-AA). As a result, I need to replace the ECU, but since I don't have the original and Ford made 7-10 different ECU's for 1990, I don't know which one I need. I've been told that it's very important to have the right unit and after doing two weeks of research, I still don't have a straight answer. I've talked with Ford Dealerships, local mechanics, etc, but no one seems to really know what the correct ECU is. Most people refer me to two ECU's that correspond to the spec's of my truck, which are (FOTF-12A650-BB) and (FOTF-12A650-CB).

Does anyone have any insight or know of anyone that might? Also, does the ECU need to be flashed / programmed?

Thanks!
Nabor J

 

Having been there, if possible, get as much information as you can from the engine labels and sticker on the driver's door and see if they can come up with the correct one.
Some of the info needed is ; exact build date of the truck, complete VIN #, engine calibration codes and all info you can get from that engine label on the valve cover.
A good parts man can get you the correct ECA , but it takes a little work on his part as long as you provide the correct info. There are some really good parts men out there that know their job, and there are some that are too darn lazy to even make an effort.
Be persistent and if necessary try different Ford dealers. One will surely be able to assist you.

 

I agree, being persistent is key to get the right part!