Automatic air conditioning system temperature sensor includes: engine coolant temperature sensor, interior temperature sensor, ambient temperature sensor, evaporator temperature sensor, solar radiation sensor, refrigerant temperature control switch. Based on these sensor signals, the control unit calculates Sensor the temperature required to blow the air into the cabin, selects the required amount of air, and then controls the air mixing inlet, the water valve, the inlet and outlet switch plate, etc., within the temperature range set by the driver Automatically adjust the temperature inside the cabin to make it the best, and automatically control the air conditioning to open and close.
When the engine coolant temperature exceeds 120 ℃ in order to protect the engine, air conditioning will stop working. Air conditioning compressor refrigerant temperature is too high, the temperature switch will cut off the compressor electromagnetic clutch circuit. The evaporator temperature sensor or temperature switch installed in the center of the evaporator controls the temperature of the evaporator by controlling the operation of the air conditioning compressor. The purpose of the evaporator temperature control Suction Control Valve is to prevent the evaporator from frosting. If the temperature of the evaporator is below 0 ° C, the moisture that condenses on the surface of the evaporator will frost or freeze, and the air passage of the evaporator will be clogged, resulting in a significant reduction in the cooling effect of the cooling system. In order to avoid the evaporator frost, it is necessary to control the temperature of the evaporator above 0 ℃. When the evaporator temperature is too low, below the set value of 0 ℃ or less, the air conditioning amplifier will cut off the compressor electromagnetic clutch circuit. Evaporator outlet temperature sensor failure, will lead to air conditioning compressor clutch frequent pull and separation. Expansion valve to the evaporator between the pipe frost, will lead to air conditioning air volume is small.
One of the conditions of the air conditioning system refrigeration is the ambient temperature is higher than the indoor temperature, the ambient temperature sensor circuit, terminal water, poor contact or poor grounding, the data flow will show the ambient temperature below -30 ℃, will cause air conditioning is not cooling.
At the same time, the engine coolant temperature sensor circuit or ground contact failure, signal misalignment, the cooling fan does not turn, resulting Fuel Rail Pressure Sensor in poor air conditioning cooling, will enter the failure protection, so that air conditioning to stop working.