Based on the pinout the PCM for MTX/ATX are the same - in the ATX case there are signals sent to a tranny module to instruct it when to shift, but for the MTX there should be no corresponding wires in the harness. There is a signal that tells the PCM that the shifter is in 'N' or 'P' for the ATX - that is the same pin that is used in the MTX to signal that the clutch is depressed - in both cases that's used at startup to allow current to flow to the starter. The only issue I can see with MTX vs. ATX is whether the PCM does anything funky with the fuel or ignition at the points it thinks the ATX (that isn't really there) is being signalled (by signals that don't go anywhere) to shift.
By the way, for anyone with their PCM or harness handy, is there any indication of a manufacturer's name on the PCM connector, e.g. AMP, Molex, etc.?
Any more thoughts on "gotchas" if I go returnless with the 2000 2.5L SVT fuel pump? Will a PCM for returnless let me stay return or do I have to go returnless if I want to use the PCM?
Eric
