Air Temperature Actuators

When the HVAC system is in the OFF mode, toggling the temperature switch up or down will enable the automatic HVAC system. If the HVAC control module displays any temperature between 19-29°C (66-84°F), toggling the temperature button up/down will increase/ decrease the set temperature by 1 degree. If the temperature setting is 30°C (85°F), toggling the temperature switch up increases the set temperature to 32°C (90°F).

The rear fuse block provides power to the left and right air temperature actuators through the ignition 3 voltage circuit. Ground is provided by the low reference circuit, the IPM and ground circuit.

The air temperature actuators are electronic stepper motors with feedback potentiometers. Zero volts drives the actuator in one direction while 5 volts moves the actuator in the opposite direction. When the actuator receives 2.5 volts, actuator rotation stops. A 5-volt reference signal is sent out over the 5-volt reference circuit, from the IPM, to the left air temperature actuator. When a desired temperature setting is selected, whether manual or automatic, the logic circuit is used to determine the left air temperature door position sensor signals value. A separate 5-volt reference is sent from the IPM to the logic circuit. The IPM software uses this reference voltage to determine the left air temperature actuator position through the left air temperature door position circuit. The motor opens the left air temperature door to a position to divert sufficient air past the heater core to achieve the desired vehicle temperature. Ground is provided to the left air temperature actuator by the ground circuits and IPM.

The right air temperature actuator operates the same as the left side. A 5-volt reference signal is sent out over the 5-volt reference circuit, from the IPM, to the right air temperature actuator. When a desired temperature setting is selected, whether manual or automatic, the logic circuit is used to determine the right air temperature door position sensor signals value. A separate 5-volt reference is sent from the IPM to the logic circuit. The IPM software uses this reference voltage to determine the right air temperature actuator position through the right air temperature door position circuit. The motor opens the right air temperature door to a position to divert sufficient air past the heater core to achieve the desired passenger temperature. Ground is provided to the right air temperature actuator by the ground circuits and IPM.