A/C Operation Description at ECM
ECM controls the A/C compressor relay and condenser cooling fan relay according to signals from HVAC control unit, A/C refrigerant pressure sensor, ECT sensor and evaporator temperature sensor. The A/C switch ON signal from HVAC control unit is transmitted to ECM through BCM. For CAN communication system, refer to CAN COMMUNICATION SYSTEM DESCRIPTION .
ECM turns ON the A/C compressor relay when the vehicle state satisfy conditions described below.
- A/C switch ON signal is inputted from HVAC control unit
- A/C refrigerant pressure is within specified range
- Evaporator temperature is within specified range
- Engine speed is within specified range
- Engine coolant temperature is lower than specified value
- Throttle opening is lower than specified value
- Vehicle is not in either state of starting or quick acceleration
- ECT sensor malfunction is not detected
- A/C refrigerant pressure sensor malfunction is not detected
Operation Procedure for Refrigerant Charge
| WARNING | Your eyes should not be exposed to refrigerant (liquid). Any liquid HFC-134a (R-134a) escaping by accident shows a temperature as low as approximately - 6°C (21.2°F) below freezing point. Should liquid HFC-134a (R-134a) is exposed to your eyes, it may cause a serious injury. To protect your eyes from such accident, it is necessary to always wear goggles. Should it occur that HFC-134a (R-134a) is exposed to your eyes, consult a doctor immediately. Do not use your hand to rub the affected eye(s). Instead, use fresh cold water to splash it over the affected area to gradually raise temperature of such area above freezing point. Obtain proper treatment as soon as possible from a doctor or eye specialist. Should the liquid refrigerant HFC-134a (R-134a) is exposed to your skin, the affected area should be treated in the same manner as when skin is frostbitten or frozen. Do not handle refrigerant near any place where welding or steam cleaning is performed. Refrigerant should be kept in a cold and dark place. It should never be stored in any place where temperature is high, e.g. where exposed to direct sun light, close to fire or inside vehicle (including trunk room). Avoid breathing fume produced when HFC-134a (R-134a) is burned. Such fume may be hazardous to your health. |
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Auto A/C System Description
The automatic type air conditioning system (auto A/C) is provided with the function to automatically control the inside air temperature, fan speed, air flow outlet direction and air intake position by HVAC control module in addition to functions of the manual type air conditioning system (manual A/C). Once the inside air temperature is set using the temperature selector, HVAC control module automatically controls the inside air temperature at the constant level at all times based on the inside air temperature, outside air temperature, amount of sunlight and engine coolant temperature detected respectively by the inside air temperature sensor, outside air temperature sensor, sunload sensor and ECT sensor. For the electronic control system components location, refer to ELECTRONIC CONTROL SYSTEM COMPONENTS LOCATION: MANUAL TYPE . For the A/C system components location, refer to A/C SYSTEM MAJOR COMPONENTS LOCATION: AUTOMATIC TYPE .
Scheme 28
Refer to OPERATION PROCEDURE FOR REFRIGERANT CHARGE: MANUAL TYPE .
