Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Dual Automatic Temperature Control (DATC)
The DATC components are used to select:
- air inlet source (outside or recirculated).
- blower motor speed.
- discharge air temperature (temperature blend).
- discharge air location (defrost, panel, floor).
- A/C compressor operation.
Control System Inputs
The DATC system has 4 control system inputs.
HVAC Control Module
The DATC system uses a remote HVAC control module that is separate from the control interface. The FCIM provides the interface for the vehicle occupants to control the climate control system. When selections are made, the FCIM communicates the selections to the HVAC control module over the vehicle module communication network. The remote HVAC control module controls the climate control system based on the FCIM selections or automatically controls the climate control system in the AUTO mode.
In-Vehicle Temperature and Humidity Sensor
The in-vehicle temperature and humidity sensor contains 2 thermistors which separately measure the in-vehicle air temperature and humidity and send those readings to the HVAC control module. The in-vehicle temperature and humidity sensor has an electric fan within the sensor that draws in-vehicle air across the thermistors.
Autolamp/Sunload Sensor (Light Sensor)
The autolamp/sunload sensor supplies information to the DATC HVAC control module to lower the A/C temperature output in the vehicle's cabin, cooling the vehicle interior and occupants.
The autolamp/sunload sensor is also used by the exterior lighting system for autolamp operation. For removal and installation of the autolamp/sunload sensor, refer to Light Sensor in EXTERIOR LIGHTING SYSTEM .
AAT Sensor
The AAT sensor signal is received by the HVAC control module over the vehicle module communication network from the PCM.
For information regarding the outside air temperature display, refer to INFORMATION CENTER - INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES .
Control System Outputs
The DATC system has 4 control system outputs. When operating in AUTO mode, the control system outputs are automatically adjusted by the HVAC control module.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.