OBD2 code P1639

Hello my name is Dave.

First question I have is did you buy a new ECU or did you get a used one? The code you have is for the VIN not being correct so the first place to start is to have the computer flashed over to your vehicle, if it is a used computer it can be very difficult to get it to take a flash over to a new vehicle. I actually own two 2005 tributes which are identical other than some body panels and trim and I made several attempts to flash one of the computers with several different scanners and was unsuccessful so I sent my original out to be repaired.

I sent mine to Module Experts however I have not received it back so I can't attest to the performance however they do offer the best price I could find and and also a lifetime warranty. These computers are notorious for bad coil drivers so I would recommend having your original repaired since they upgrade the drivers. If you could give me the additional information as to if it was new, re-manufactured or used as it's of special interest to me since I have just purchased 2 of theses. I look forward to hearing back from you and thank you for using 2CarPros!

Hi again.

Well it sounds like there is possibly a problem with the fuel pressure sensor/regulator circuit or the sensor itself. However it is important to get more information about your replacement ECU, where did you buy it and how did you have it programmed? If it is a used unit then there is a fairly high likelihood that that can be the cause of your issue. Do you know what codes/symptoms you had in/with the original ECU?
That information would be greatly helpful in narrowing down your current problem, if you have all or some of the original symptoms/codes then we need to look somewhere other than the ECU, if these symptoms/codes are new I would be highly suspicious of the replacement ECU provided it was properly installed and no damage occurred during the installation process.
If you could give us as much of this information that you have we will be able to guide you more efficiently.