Ok so I got a cheap 06 f150 5.4 3v 2wd with a bad trans and bought a 4r75 from a expedition to swap. The expedition trans only had the rear speed sensor and the fron one blocked off. I installed both the speed sensors from my original 4r75. I installed the trans and took for a test drive and I’m getting a speed sensor fault from the front speed sensor. The code I’m getting is a p0715. I did install a 1900-2200 stall torque converter instead of the 1600-1800 style. Wondering if that has anything to do with my isssue as well. Any input is appreciated

 

The trans needs to be from a 2006 or newer to be fully compatible.

 

the guy I got it from said it was out a 06 expedition

 

I don't know exactly why, but those 2 transmissions do not cross reference.

 

Is there no wheel for the trans to read? Pretty much need to find a new trans?

 

Uploaded a pic of the trans I used. You can see the block plate on the input speed sensor

 

With Ford, when there's a block off plate over the input speed sensor it means the inside of the gearbox is also missing the reluctor ring necessary to give you an input sensor signal. Putting a sensor there when there's no ring inside to read from is the same thing as putting a camera in an empty room. This means either the computer on the Expedition you snagged the gearbox from either assumes a number through mathematics, or it gets the signal from somewhere else. For your case, you may need to get the wiring harness from the Ex, you may need to get the trans computer from the Ex, you may need to flash your computer, I'm not sure, but there is ALWAYS a reason why a Ford cross reference number leaves a particular model out. You need to call the dealer parts guy in the morning, tell the parts guy what you've done, and see if he or any of the techs can tell you a solution; that will be way way quicker than relying on the rest of us keyboard warriors; because I guarantee you, someone else has probably already done this, and the dealer has probably already documented the solution; the question will be whether or not they're willing to tell you

Best of luck.