Originally posted by DR1665
EDIT2: Just to be on the safe side, is this schematic still current? Or have there been changes made to work with the 4G63 ignition modules? http://www.2gnt.com/www/slick/images/ms2gntwiring.gi f

Pin 25 (X11) goes to IB1 on the 4G63 module, pin 27 (X12) goes to IB2, pin 29 (X13) is used for either water injection or fan control, and pin 31 (X14) can either be used for boost control, or to output any variable that the MS has access to such as manifold pressure, coolant temp, intake temp, RPM, spark advance, pretty much anything.

X11, X12, X13, and X14 aren't hooked up to anything on a bare board. For example, to get the spark outputs from the D17 and D19 LED's on the RS232 side of the board to X11 and X12 you would run some vector wire over. Same goes for X13, where you would have to build a circuit that takes X2 and amplifies the signal so that it can handle driving a relay, then send the output of that amplifier to X13 which is actually connected to the relay that either controls a radiator fan or water injection.