K 1500 Suburban 4WD V8-4.8L VIN V (2003)
reference, control, 5-volt reference and position signal circuits enable the actuator to operate. The control circuit uses either a 0, 2.5 or 5-volt signal to
command the actuator movement. When the actuator is at rest, the control circuit value is 2.5 volts. A 0 or 5-volt control signal commands the
actuator movement in opposite directions. When the actuator shaft rotates, the potentiometer's adjustable contact changes the door position signal
between 0-5 volts.
The auxiliary HVAC control module uses a range of 0-255 counts to index the actuator position. The door position signal voltage is converted to a
0-255 count range. When the module sets a commanded, or targeted, value, the control signal is changed to either 0 or 5 volts depending upon the
direction that the actuator needs to rotate to reach the commanded value. As the actuator shaft rotates the changing position signal is sent to the
module. Once the position signal and the commanded value are the same, the module changes the control signal to 2.5 volts.
