The climate control unit performs air conditioning according to the operation by the users and the driving conditions of the vehicle.
The climate control unit determines optimum air-conditioning based on the input signals from each sensor and the control module and the operation signals from the control panel, and controls each actuator, A/C compressor, and the blower motor. (See FULL AUTO AIR CONDITIONER [FULL-AUTO AIR CONDITIONER].)
When the ignition is switched ON after the climate control unit is replaced, the climate control unit reads the vehicle specification information sent via CAN transmission from the instrument cluster using the automatic configuration function, and stores it.
A logic-type climate control unit has been adopted.
The climate control unit consists of a control panel, display panel, and a control unit.
The switches and dials shown in the figure are positioned on the control panel.
The display panel shows the followings:
Air conditioner system display
Clock display
Seat belt warning light
Passenger air bag deactivation (PAD) indicator
Fail-safe function table
If a malfunction is detected by the malfunction detection function, the fail-safe function performs the following controls to prevent an operation malfunction of the full-auto air conditioner and malfunction of output devices.
| Part where malfunction is determined | Malfunction determined when ignition switched ON | Malfunction already exists when ignition switched ON |
| Ambient temperature sensor | Ambient temperature sensor input value is fixed at the value right before the malfunction. | Ambient temperature sensor input value is fixed at 15 °C {59 °F}. |
| Passenger compartment temperature sensor | Passenger compartment temperature sensor input value is fixed at the value right before the malfunction. | Passenger compartment temperature sensor input value is fixed at 25 °C {77 °F}. |
| Evaporator temperature sensor | A/C output OFF is controlled when the evaporator temperature sensor input value is at 0 °C {32 °F}. | ← |
| Solar radiation sensor | The solar radiation sensor input value is fixed at the value directly before the malfunction only when the valve is 1,450 W/m2 or more. | Solar radiation sensor value is fixed at 0 W/m2. |
| Engine coolant temperature sensor | Engine coolant temperature sensor input value is fixed at 85 °C {185 °F}. | ← |
| Air mix actuator (potentiometer) | Air mix actuator drive signal is stopped right when the malfunction is determined. However, it is fixed at MAX COLD when the manually set temperature is at 15 °C {60 °F} and fixed at MAX HOT when the manually set temperature is at 32 °C {90 °F}. | Control based on ambient temperature. (See Graph 1.) However, it is fixed at MAX COLD when the manually set temperature is at 15 {60 °F} and fixed at MAX HOT when the manually set temperature is at 32 °C {90 °F}. |
| Airflow mode actuator (potentiometer) | Airflow mode actuator drive signal is stopped right when the malfunction is determined.
| Control based on ambient temperature. (See Graph 2.)
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| Air mix actuator (motor lock) |
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| Airflow mode actuator (motor lock) |
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