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13.8
Step motor idle speed
Its control is done through the four yellow outputs of the 16-way connector, also used for electronic throttle control.
After selecting the idle speed control as step motor (as guides chapter 7.6) the four yellow outputs are automatically set
Below are some known step motor connections.
VW step motor - Magneti Marelli
GM step motor Delphi
Important note: step motor is calibrated every time the ECU is turned on, so, before cranking the engine, it is
recommended to wait about 2s after turning the ignition switch on. If this procedure is not respected, the engine may be
revved up unwittingly during the step motor calibration, coming back to normal within seconds.
If your step motor is different from the ones listed here, do what follows:
1.
Put a tester on the 200 Ohms range;
2.
Measure the step motor actuators until you find a resistance of approximately 50 Ohms. T
coils;
3.
Connect yellow #1 and yellow #3 to a pair of coils and yellow #2 and yellow #4 to the other pair.;
4.
If the step motor remains fully opened after the calibration, change yellow #1 by yellow #3 position.
FT500 step motor control is compatible with the great majority of actuators nowadays. Usually, with this simple
