1998 Mustang Gt Pats Issues And New Pcm

Discussion in 'SN95 4.6L Mustang Tech' started by banshee442, Oct 2, 2013.

  1. I will try to keep this short...

    I developed a miss on driver side cyl, closest to the firewall. replaced coil, wire, plug, ect to no avail. Had no spark whatso ever. last effort was to try the PCM. Order a PCM for $200 form the east coast. Install, wont start and flashes "theft". So I take to the delaer and buy a new key, and pay for them to sync the two keys to the new PCM. They tell me the new PCM took the program, but would not start and still flashed "theft" I then pay the full price and leave. I get it home, swap the old pcm back, and fires right up on 7 cyls as it did before. This is supercharged and has a custom tune off a diablo sport, but I fail to see how that would make a difference. Any suggustions" I'm ready to sell this thing.
  2. Have you confirmed getting electricity to the wire?
  3. I did. Even made a jumper wire and still no luck
  4. Original engine?
  5. It obviously DID NOT take the program. Why? Because the original PCM started the car.

    During the re-programming process for the 98+ model years, the re-programming modifies the PCM and the cluster. The PCM and the cluster are programmed for EACH other. Changing either one breaks PATS.

    Soooooo if the dealer did their job correctly, then the original PCM would not have worked because the cluster would have been changed.

    Since the original PCM worked, IMO that means that the cluster was not re-programmed.

    My suggestion. Go back to the dealer and get the service that you paid for.

    Or get a hand held tuner with a custom tune. In the custom tune have PATS disabled (unless PATS is disabled on the original PCM then disregard everything above).
    #5 wmburns, Oct 4, 2013
    Last edited: Oct 4, 2013