ACTIVE AIR SHUTTER CONTROL

id092300000200

Outline

• In the active air shutter control, the PCM controls the active air shutter actuator to open/close the shutter.

• The controlled functions are as follows:

Control Table

Control	Function	Content
Basic control	1. Basic function (See 1. Basic function.)	• Opens/closes the shutter according to the vehicle speed, engine coolant temperature, or the load condition due to A/C operation.
Basic control	2. Shutter fully open/closed position learning function (See 2. Shutter fully open/closed position learning function.)	• Learns the shutter fully open/closed positions by opening/closing the shutter.
Protection control	1. Engine protection function (See 1. Engine protection function.)	• Opens the shutter to protect the engine if it is estimated that the engine coolant temperature is high or the engine oil temperature increases excessively.
	2. ATX protection function (See 2. ATX protection function.)	• Opens the shutter to protect the ATX if the ATF temperature is high.
	3. Throttle valve protection function (See 3. Throttle valve protection function.)	• Opens the shutter to prevent the engine oil temperature from increasing rapidly when the intake air temperature is low.
Fail-safe (See Fail-safe.)		• Opens the shutter if the active air shutter control has a malfunction.

Block Diagram

am3uun00003156

Operation

• The shutter is fully open when the ignition is switched off.

• The shutter is controlled in three positions; 0 ° (fully closed), 66 ° (66 ° open from fully closed position), and 90 ° (fully open).

Note

• With the shutter opened to the 66 ° position, more air flows to the radiator and condenser while driving than with the shutter fully open.

am3uun00003241

• The PCM opens/closes the active air shutter depending on the conditions after the shutter fully open/closed position learning is completed.

• The PCM opens/closes the shutter in the following control sections.

am6xun00001760

Basic Control

1. Basic function

• The PCM fully closes the shutter when all the following conditions are met.

― Vehicle speed: less than 140 km/h {87.0 mph}

― Engine coolant temperature: less than 100 °C {212 °F}

― Load condition due to A/C operation: vehicle speed and refrigerant pressure during A/C operation are the specified values or less

― Protection control is not operating

• If any of the following conditions is met, the PCM opens the shutter to the 66 ° position.

― Vehicle speed: 140 km/h {87.0 mph} or more

― Engine coolant temperature: 100 °C {212 °F} or more

― A/C operation is in the following range (to cool the condenser)

am3uun00003297

2. Shutter fully open/closed position learning function

Note

• After the main relay turns off (specified time has elapsed since ignition is switched off), the shutter fully open/closed positions recorded in the active air shutter actuator are cleared.

Shutter fully open/closed position learning function flow

1. After the ignition is switched ON, the PCM moves the shutter to the 90 ° (fully open) position when the vehicle speed is 10 km/h {6.2 mph} or more.

2. After the shutter reaches the 90 ° (fully open) position, the PCM moves the shutter to the 0 ° (fully closed) position.

3. When the shutter reaches the 0 ° (fully closed) position, the shutter fully open/closed position learning function is completed.

am3uun00003669

• If an error occurs during the shutter fully open/closed position learning and the learning is not completed, the PCM performs the learning again (to maximum 3 times).

Protection Control

1. Engine protection function

• If any of the following conditions is met, the PCM opens the shutter to the 66 ° position to protect the engine until the ignition is switched off.

― Engine coolant temperature: 116 °C {241 °F} or more

― Engine oil temperature control of drive-by-wire control is operating*

*: This function is synchronized with the engine oil temperature control of the drive-by-wire control. For details on the engine oil temperature control, refer to the DRIVE-BY-WIRE CONTROL. (See DRIVE-BY-WIRE CONTROL [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) In addition, when this function operates, the PCM sends a master warning light on request to the instrument cluster. (See MASTER WARNING LIGHT.)

2. ATX protection function

• For ATX protection, when the PCM receives a cooling fan operation request signal from the TCM, the PCM opens the shutter to the 66 ° position until the ignition is switched off to prevent the ATF temperature from being excessively high, and also to lower the frequency of fail-safe operations which operate when the ATF temperature is high.

3. Throttle valve protection function

• When the intake air temperature is -5 °C {23 °F} or less, the PCM opens the shutter to the 66 ° position to prevent the engine oil temperature from increasing rapidly.

• By opening the shutter, a rapid increase in engine oil temperature is suppressed to prevent the blow-by gas from freezing and adhering to the throttle valve.

Note

• If the flow amount exceeds the allowable flow amount of the PCV valve, the blow-by gas flows inside the air hose via the ventilation hose.

The blow-by gas is cooled by the cool intake air and condenses to water, and the water freezes by being cooled furthermore. If this ice adheres to the throttle valve, it may affect the throttle valve operation. In addition, if the engine oil temperature increases rapidly, fluid in the engine oil in the crank case evaporates and mixes with the blow-by gas. To prevent this, the shutter is opened when the intake air temperature is low to suppress rapid increase in the engine oil temperature.

Fail-safe

• If any of the following DTCs is stored, the PCM opens the shutter to the 66 ° position.

― Intake air temperature sensor No.1 malfunction (P0112:00, P0113:00)

― Engine coolant temperature sensor malfunction (P0117:00, P0118:00)

― Vehicle speed signal error (P0500:00)

― Active air shutter malfunction (P059F:00, P05A0:00)