I own a 1999 F150 X Cab with a 4" lift kit and 33" tires. I bought it set up this way 8 months ago and shortly thereafter, the automatic overdrive transmission light started flashing. I took it to my Ford dealer and they told me that I needed a new transmission. I paid them $2,800 and had it replaced. A week later, it started again. I have taken it back to Ford a total of 6 times and they keep telling me that all they can do is reset it and then they can never get it to duplicate again. 7-14 days later it starts up again. I keep taking it back and have been to all 3 Ford dealerships in my area, with no change. I am really getting fed up with it. Two weeks ago, a guy at an automotive place (not Ford) starts asking me questions about my truck and how it's been running, stating that he had a buddy with almost the same truck. I tell him the problem. He tells me that he knows what the problem is as his friend had the same problem and explains that Ford technicians are only able to reset the vehicle settings to "factory". He explains that my truck has obviously had some modifications done to it with regard to the gear ratio, tire size, etc. He stated that the computer was probably never modified to adjust to these modifications. He pulls the code and it reflects code #P0781 which is a 1-2 shift error. He then checks my tire size and gear ratio and sells me (for $400) an Excalibrator Multi-Program OBD II Flash Device, reprograms it with the new information and transfers it to the computer in my truck, changing the settings accordingly to accomadate the truck tires and gear ratio. The truck ran just awesome for about a week (better acceleration, shifting, overall performance, etc.) with no problems, then the O/D Transmission malfunction light started flashing again. I took it back and he reprogrammed it again and 24 hours later, the same thing, he reprograms it again and the same thing 72 hours later, I take it back today and he redoes it again (modifying it each time) and 3 hours later it's doing it again, go back and leave again and 2 hours later it's happening again. By then it was the close of the day, so I am headed back again tomorrow and probably every other day this week. What is the deal? I am really just flat out sick and tired of this. Can anybody give me any help? I can't keep paying this kind of money over and over, not to mention the time involved. My patience is almost gone, PLEASE HELP!

 

First off, as you probably know by now that guy is just ripping you off. There is NOTHING that can be programmed for different tires/axle ratios that will cause or fix a 1-2 shift error code.

You need someone that can diagnose what's wrong with the 1-2 shift. The computer is detecting that something isn't right when the transmission makes the 1-2 shift. Now that it is happening much more often a good tech should be able to find the problem.

 

I took it back to Ford (reluctantly) and made a comaplint to the service manager. They took my truck for a week and claim (once again) to have put in another remanufactured transmission. We shall see if the problem has been corrected or not. All that they would tell me was that the other new transmission had something wrong with it. When I asked them what that something was, they told me that it was just something, with no further explanation. I asked to see the other transmission and was shown one, but it could've been from anything as I am no mechanic.

 

I would look the wiring harness on the outside over really good. A melted wire can cause all sorts of problems. After that there are a few things that can be checked by dropping the pan, but I won't go into that again.
Alan