Let's be clear: Stepper motors are our least favorite idle air valve option. We are not excited about them at all. microRusEFI can control a 4-wire stepper motor using the on-board TLE8888 - see this ...
2V W60 0Ohm YEL/BLK Injector #2 Output/low side 2Y W63 0Ohm GRN/WHT Injector #3 Output/low side 2Z W64 0Ohm GRN Injector #4 Output/low side Source: http://www ...