故障现象一辆雷克萨斯GS300车,搭载3GR-FE发动机,累计行驶里程为30万km。车主反映,该车在拥堵的市区行驶时空调制冷效果非常差,但是车速升高之后空调制冷效果会稍微好些。故障诊断接车后试车,起动发动机,接通A/C开关,将出风模式设置为吹脸,内外循环模式设置为内循环,温度设置为最低,发现空调制冷效果良好;对比驾驶人侧和副驾驶人侧的温度,没有区别;用手触摸空调低压管,发凉,但并不是特别的凉。试车至此,并没有出现车主 Fault phenomenon A Lexus GS300 car, equipped with 3GR-FE engine, the cumulative mileage of 300000 km. Owners reflect the car driving in the congested urban air conditioning and cooling effect is very poor, but after the speed increase air conditioning and cooling effect will be slightly better. Fault diagnosis After the car to take the test, start the engine, turn on the A / C switch, the air mode is set to blow the face, internal and external circulation mode is set to internal circulation, the temperature is set to a minimum, found that air conditioning and cooling effect is good; contrast driver side and Co-driver side of the temperature, there is no difference; touch the air conditioning low pressure pipe, cool, but not particularly cool. At this point, there is no car owners