9000 Hatchback L4-2290cc 2.3L DOHC Turbo EFI (1994)
Air Door Actuator / Motor: Description and Operation
Stepping Motor, Air-Mixing Damper
Stepping Motor, Air Mixing Damper
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The stepping motor has two windings. A voltage is applied to the windings in a particular order by the output signal changing polarity at each
pulse. This makes the motor move in short steps, hence the name stepping motor. The direction of rotation can be changed.
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When the motor is stationary, both windings are continuously powered. Winding 1 is connected to pins 27 and 28 on the ACC control module.
Winding 2 is connected to pins 29 and 30 on the ACC control module.
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A stepping motor requires no feedback to the ACC control module. By sending a particular number of impulses, the ACC control module always
knows how far the flap has moved. For this, the control module must be calibrated. During calibration, the damper is turned to 0 % heat.
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Calibration is carried out using the ISAT scan tool or by simultaneously pressing the "AUTO" and "VENT" buttons. Calibration must be carried
out if the battery has been disconnected or discharged or if the ACC control module or the stepping motor has been changed.
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The air mixing damper is set by the ACC control module using information from the blended air temperature sensor in order to achieve a suitable
blended air temperature. The cabin temperature, outside temperature and selected temperature are decisive for the blended air temperature.
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If the selected temperature is "HI" or "LO", the blended air flap will be set to the max. heat or max. cold position.
