The ME platform (all models) supports 6-wire stepper  - for 4 wire stepper you will need either the ME442-DBW version or the ME ECU which has the H-Bridge Drivers x2 for stepper control.


For installation and wiring please see here.


Once you have wired the stepper, and configured the channels in the IO Settings, follow the below quick start/test guide:


  1. Set the Idle Drive to "Stepper".
  2. Set the control mode to "Manual"
  3. Set the "Number of Steps" to the minimum number of steps the motor needs to take to go from fully open to fully closed (the stepper is pulsed "closed" this many steps at key-on to wind it back to zero/no air flow).
  4. The step-time is the milliseconds between pulses to allow the motor to move- typically 15-80mS is normal but the motor specification will tell you the correct value.
  5. Power Cycle the ECU.


Now, with the engine running, varying the Manual Duty % will vary the motor position, and hence, vary the RPM. You can then follow the normal PWM Idle tuning procedures as the Steppers range is now mapped onto the Idle % much like a PWM valve.


If more Duty results in Less airflow/engine RPM, you can toggle the "Normal/Reversed" option in the Idle Stepper Settings.