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X4 won't tune 2001 Ford Lightning

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  • X4 won't tune 2001 Ford Lightning

    I am the original owner of a 2001 Ford Lightning with 18,000 (not a typo, 18,000) miles on it. In May of 2022 I started a round of mods that included a tuner and custom tune. I am only able to work on the truck an hour or two per month if I'm lucky, and between that and waiting on parts it was September when I was finally ready to tune it and fire it up. Prior to this the PCM has never been tuned, flashed or in any way accessed other than my MT2500 to read data. I did start the truck with the stock tune and it runs and drives great other than being a little rich. When I plugged in the X4 everything went correctly until it actually tried to send the tune to the truck. When I got to that point it just sat there and did nothing for several minutes. I tried it again a few times waiting up to an hour with it doing nothing. It did read the VIN and store it, so communication is there. I sent an email to tech support and got a message back saying that I would need to call to resolve the issue.

    During that call we checked battery voltage, tried to tune it with a battery charger connected, and disconnected the battery to reset the PCM. None of that changed anything. The tech I was speaking to suggested that the problem could be the FEPS voltage. He explained that FEPS is a signal from the PCM to the X4 to unlock the X4 and allow it to load the tune to the PCM. That really didn't make any sense, but he was going to send me a procedure to check the FEPS voltage, which I was able to check the next day. I had 17.5V on pin 13. The procedure he sent directly contradicted what he had told me about the FEPS signal being sent from the PCM to the X4. It said it was a signal from the X4 that unlocked the PCM. That makes a lot more sense. I called tech support back and told them what I found and they insisted it was a bad PCM, which I disagree with. The tech suggested that I find another vehicle to try it on, which seemed reasonable. The problem was finding someone that was willing to let me plug in a tuner that every one except SCT says is faulty and try it on their vehicle. I was finally able to try it on a Ranger and it wouldn't even communicate with the truck.

    At this point I decided to go a little farther with my testing. I removed pin 13 from from my OBDII connecter and measured the voltage coming from the truck. Zero volts. Then I backprobed cavity 13 in the OBDII connecter to see if there was voltage from the X4 and it was 17.5V. This supported my theory that the FEPS signal goes from the X4 to the PCM as stated in the troubleshooting document I received. After confirming that the voltage was coming from the X4, I used an 18V power supply to feed 18V to pin 13 to see if I could get it to tune the truck like that. Still the same; the X4 just sits there forever and does nothing.

    I have since tried calling tech support multiple times and have been unable to reach anyone, even after sitting on hold for over an hour, and nobody calls me back when I choose that option. I really need to get this resolved. This is my first experience with SCT and so far it has not been a positive one. Does anyone have any other ideas? Or am I just the proud(?) new owner of an expensive wheel chock?