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!

 

Two things to check on..First the easiest. Make sure that you are at the CORRECT fluid level. If you are too low to too high, it will flash the OD light. Resetting it will only make it come back on later. If too much fluid, then drain some either by loosening the pan and draining, or if you have a tranny cooler, you can disconnect one of the hoses and let some drain that way. Afterwards, disconnect the battery for 20 minutes to reset ALL codes. This will also reset everything back to factory so you will have to hook up the programmer again to get your performance settings. If that doesn't do it, then try replacing the VSS sensor on the side of the tranny. Reset codes the same way again. 20 minutes is pretty much standard for resetting the puter and codes.
Let us know how it goes.

 

yes indeed.


Fluid is probably your problem, another problem i've heard about was the one already addressed the change in tires and all of the mods, so make sure if you replace sensor or check fluid and thats the problem, that you still get codes back to reg. it actually is important.

 

make sure to check the fluid .it could be the fluid but its unlikely that the new trannie and the old one would both have a problem with the fluid level and that none of the mechanics that you have taken it to could find a bad level. did the lift do anything to the harness/connectors, are any of the wires chaffed. when the code sets is there a change in the truck performance? have you noticed if its raining when the code sets or is dry. make sure to check all the wires under the hood to. take it back to ford and have them check/change the sensor that is throwing the code, they should be able to offer some kind of warranty and fix your problem.