故障现象一辆2009款帕萨特1.9L TDI柴油车,搭载BPZ发动机,出现空调不制热的故障。故障诊断经检查发现,无论停车或行驶,无论低速或高速,仪表板上各出风口均无暖风吹出。观察仪表盘,显示冷却液温度正常。打开发动机室盖,发现冷却风扇工作正常,而膨胀箱液位偏低。接通A/C开关,仪表板上的各出风口均有冷风吹出,而一将温度调节开关调到制热挡,冷风即被屏蔽,转而吹出自然风,无暖风吹出,这说明各风门及其控制机构 Fault phenomenon A 2009 Passat 1.9L TDI diesel car, equipped with BPZ engine, there is no air conditioning heating fault. Fault diagnosis After inspection found that, regardless of parking or driving, regardless of low speed or high speed, the dashboard of the outlet are no warm air blowing. Observe the dashboard to show that the coolant temperature is normal. Open the engine room cover and found the cooling fan is working properly, while the expansion tank level is low. Turn on the A / C switch, the outlet of the dashboard have cold air blowing, and a thermostat switch to the heating block, the cold air is shielded, instead of natural wind blowing, no warm air blowing, which shows that the Throttle and control mechanism