A/C System Description

WARNING: This page is about a different variant/trim than selected.

The Air Conditioning is a system that controls the interior space to a comfortable environment.

Air Flow Diagram

NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model.

Courtesy of HONDA, U.S.A., INC.

Refrigerant Cycle

NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model.

Courtesy of HONDA, U.S.A., INC.

Climate Control

Courtesy of HONDA, U.S.A., INC.

The climate control system transmits signals appropriate signals to each motor based on the information (sunlight, humidity, in-car temperature, outside air temperature) received from each sensor. See below for details.

Air Mix Control Motor: The system controls the air temperature coming into the cabin by mixing the ratio of warm and cold air. The air mix control motor adjusts the air mix door to regulate the desired temperature.
Mode Control Motor: The system directs the airflow to the specified area (VENT, HEAT/VENT, HEAT, HEAT/DEF, or DEF). The mode control motor switches the mode control door to the selected position.
Recirculation Control Motor: The recirculation control motor switches the recirculation control door position to the "FRESH" or "RECIRCULATION".
Blower Motor: The blower motor changes the air volume based on the voltage adjusted by the power transistor.

The climate control unit optimizes these controls in order to maintain passenger comfort.

Relationship between Vent (Air Outlet) Temperature and Actual In-Car Temperature

The climate control unit can automatically control vent temperature (air mix position), blower motor speed, blower intake, and the electric A/C compressor operation to raise or lower the vehicle's interior temperature to match the customer's temperature setting. The actual vent outlet temperature largely depends upon the difference between the in-car temperature sensor reading and the customer's temperature setting.

Warm-Up Control

If the customer wants to warm-up the interior when no heat is available because the engine coolant temperature is low, the climate control unit will slow the fan speed to avoid ventilating cold air. The climate control unit will gradually increase the fan speed as the engine coolant temperature rises.

The climate control system will control this process when the following characteristics are present:

Fan speed is set to "AUTO".
Air outlet position is set to "AUTO", "HEAT", or "HEAT/DEF".
Outside air temperature is less than 68 deg.F (20 deg.C).
Engine coolant temperature sensor and outside air temperature sensor are normal.
Engine coolant temperature is less than 131 deg.F (55 deg.C).

Low Engine Coolant Temperature Control

When the engine coolant temperature is low, the climate control system changes an air outlet position to the "DEF". When the engine coolant temperature increases, the climate control system controls the air outlet position and outlet air temperature automatically.

Revision because of Sunlight

When the air conditioner is operating, if fan speed is set to "AUTO" and air outlet position is "VENT" or "HEAT/VENT", the climate control unit raises the fan speed depending on the strength of the sunlight.

Relationship between Vehicle Speed and Blower Intake Mode

Because the air resistance is different between fresh air and recirculated air, the volume of air coming through the vents would be different if the fan speed was constant. When the recirculation control door is set to "FRESH", the fresh air flow increases as the vehicle speed increases. The climate control unit regulates the fan speed so that the air volume is the same when "FRESH" or "RECIRCULATION" mode is selected.

A/C Control

To prevent the evaporator from freezing, the climate control unit switches the electric A/C compressor ON and OFF based on the evaporator temperature sensor value. While in the automatic operation mode, the climate control unit automatically varies the electric A/C compressor operation time based on the evaporator temperature sensor value, as well as the outside air temperature, inside air temperature, and humidity.

MAX Control

When the temperature setting is adjusted to "MAX COOL (Lo)" or "MAX HOT (Hi)", the climate control unit overrides automatic control and defaults to the following operation:

MAX COOL
"RECIRCULATION", "VENT", blower fan maximum speed, and A/C system ON.
MAX HOT
"FRESH", "HEAT*", blower fan maximum speed, and A/C system ON.*: If the sensor information indicates that the windshield may fog, the air outlet switches to "HEAT/DEF" automatically.

ECON Control

Electric A/C compressor load control
Reduces load on electric A/C compressor by slightly raising the target temperature of the evaporator.
Blower fan speed control
Control the blower fan speed low compared to normal operation for an energy-saving operation with low air volume.

Customize Function

How to Change the Set Temperature (Climate Control Panel with Display)

The climate control unit has a function to change the set temperature +2.7 deg.F (+1.5 deg.C) or -2.7 deg.F (-1.5 deg.C) in case the customer feels the temperature is too warm or too cold for the displayed temperature.

NOTE: Verify that the climate control and A/C system is working properly before using the customize function to offset the set temperature.

Turn the vehicle to the ON mode, then based on the desired temperature change, set the temperature condition on the temperature control dial according to the table.
Turn the climate control system OFF then turn the vehicle to the OFF (LOCK) mode.
Depending on desired setting change, press and hold the pair of buttons according to the table.
While holding the buttons, turn the vehicle to the ON mode.
Keep the buttons pressed for 10 seconds.

Setting	Temperature Condition	Buttons
+2.7 deg.F (+1.5 deg.C) Change	Hi	Courtesy of HONDA, U.S.A., INC.	Courtesy of HONDA, U.S.A., INC.	or	Courtesy of HONDA, U.S.A., INC.
-2.7 deg.F (-1.5 deg.C) Change	Lo	Courtesy of HONDA, U.S.A., INC.	Courtesy of HONDA, U.S.A., INC.	or	Courtesy of HONDA, U.S.A., INC.
Changing back to 0 deg.F (0 deg.C)	Except Hi or Lo	Courtesy of HONDA, U.S.A., INC.	Courtesy of HONDA, U.S.A., INC.	or	Courtesy of HONDA, U.S.A., INC.

Indication of the change
The climate control unit displays the following during each change.
- -
  Displays nothing from the vehicle ON mode for 5 seconds.
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  Blinks the current setting for the next 5 seconds.
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  The display will indicate a Hi, Lo or two dashes depending on the set temperature change.

Courtesy of HONDA, U.S.A., INC.

How to exit the A/C User Customizing
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  Turn the vehicle to the OFF (LOCK) mode, or press a button other than the RECIRCULATION and the REAR WINDOW DEFOGGER/MIRROR DEFOGGER on the control panel.

How to Change the Set Temperature (Climate Control Panel without Display)

The setting temperature is only displayed in degrees centigrade (deg.C).

NOTE: Verify that the climate control and A/C system is working properly before enabling the customize function to offset the set temperature.

Turn the climate control system OFF then turn the vehicle to the OFF (LOCK) mode.
Press and hold the pair of buttons according to the table.
While holding the buttons, turn the vehicle to the ON mode.
Release the buttons, then select the desired temperature shift icon on the display.

Buttons
Courtesy of HONDA, U.S.A., INC.	Courtesy of HONDA, U.S.A., INC.	or	Courtesy of HONDA, U.S.A., INC.

NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model.

Courtesy of HONDA, U.S.A., INC.

How to exit the A/C User Customizing
- -
  Turn the vehicle to the OFF (LOCK) mode, or press a button other than the RECIRCULATION and the REAR WINDOW DEFOGGER/MIRROR DEFOGGER on the control panel.