Something wrong with Toyota Camry air conditioning

A mileage about 68000km キセノンランプ2004 Toyota Camry 2.4 cars. The owners said: car air conditioning sometimes refrigeration, and air conditioning (A / C) indicator blinks.

Reflects the owner. The car has to replace the air conditioning compressor, but the fault remains. Diagnostic system of the car's air conditioning, no communication with the diagnostic interface (DLC), only through 車LEDライトthe air conditioning control panel self-diagnosis function detects: press the the AUTO keys on the air conditioning control panel and within Xi Bu cycle key, turn ignition switch, all running the air conditioning control panel display and temperature settings should be lit. All the lights flashing, the system after detection sensor fault code displayed on the monitor. Obtain fault code, only due to the dim lighting daylight sensor failure. Turn on the air conditioning switch, air conditioning compressor work. The air conditioning can refrigeration situ test run for a long time, there is no air conditioning cooling failure phenomenon, so he road test, about 30 min after the failure. Vent blowing natural wind, air conditioning compressor electromagnetic clutch does not pull.

Disconnect and turned on the air conditioner switch again. The air conditioning compressor electromagnetic clutch instant pull. Went off. Air conditioning compressor control circuit (Figure 2), with test lamp ecu チューニングterminal 3 is connected to one end of the air-conditioning compressor electromagnetic clutch relay: other end Datie. Test lamp is instantly lit and then turns off. Turn on the air conditioner switch instantly. Air conditioning compressor electromagnetic clutch relay terminal 2 Ground signal, but instantly disappear. Analysis shows that air conditioning compressor circuit diagram relay terminal 2 Ground signal is output by the engine ECU. According to the failure phenomenon. Suspect the failure is caused by the air conditioning compressor speed signal fails to promptly delivered to the engine ECU and the engine ECU that the air-conditioning compressor Hugging, thereby cutting off the air conditioning compressor electromagnetic clutch relay Ground signal to protect the air-conditioning compressor . Therefore determine the fault may be due to two aspects:

First, the lower the temperature of the evaporator and air conditioning pipe pressure is too high;

Second, the air conditioning 自動車パーツcompressor electromagnetic clutch relay with the air conditioning compressor lock sensor failure.