Temperature Blend Door Actuators

The dual-zone EATC system utilizes two temperature blend door actuators to control two separate temperature blend doors which independently vary the LH and RH temperature settings. The temperature blend door actuators:

• are located on the heater core housing.
• move the temperature blend doors on command from the dual-zone EATC module.
• contain a reversible electric motor and potentiometer. The potentiometer wiper is connected to the actuator output shaft and moves with the output shaft to indicate the position of the temperature blend door.
• receive a 5 volt signal at one end of the potentiometer. The voltage available at the wiper indicates the position of each potentiometer. The expressed value of the actuator wiper voltage is sent to the dual-zone EATC module and is matched with an expected wiper voltage value. The control module then drives the actuator motor in the direction necessary to make the actuator wiper voltage match with the expected dual-zone EATC module setting.