S15/T15 Sonoma P/U 2WD L4-2.2L VIN 5 Flex Fuel (2001)
Air Door Actuator / Motor: Description and Operation
HVAC Systems - Automatic
When the HVAC system is in the OFF mode, turning the air temperature switch will deliver the incoming forced air through any of the mode outlets. The
temperature knob can dial in temperatures between 19-28°C (66-82°F). If the temperature knob is turned past 19°C (66°F), the HVAC control module
will go into maximum cooling mode.
If the temperature knob is turned past 28°C (82°F), the HVAC control module will go into maximum heat mode. Using the maximum temperature modes
will not heat or cool the vehicle any faster.
The instrument panel fuse block provides power to the air temperature actuator through the ignition 3 voltage circuit through a splice pack. Ground is
provided by the low reference circuit and HVAC control module.
The air temperature actuator is an electronic stepper motor with a feedback potentiometer. The air temperature door position signal circuit sends a
voltage signal to the actuator. 0 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 HVAC control module, to the
air temperature actuator. When a desired temperature setting is selected, whether manual or automatic, the signal circuit is used to determine the air
temperature door position sensor signals value. The HVAC control module software uses this reference voltage to determine the air temperature actuator
position through the air temperature door control circuit. The motor opens the air mixture door to a position to divert sufficient air past the heater core to
achieve the desired vehicle temperature. Ground is provided to the air temperature actuator by the low reference circuit and HVAC control module.
When servicing the actuator, replace parts with the correct service parts for the actuator being serviced. The electric actuator for the automatic climate
control system (C68) has a green R on it. This is used to differentiate between the actuator used on the automatic system from the actuator used on the
manual systems (C42 and C60).
"For a description of the RPO Code(s) shown in this article or any of the images therein, refer to the RPO Code List found at Vehicle/Application ID".
See: Application and ID/RPO Codes
