1. Expansion valve faulty

The low-pressure pipe of automobile air conditioner is frozen, which is probably because the expansion valve is faulty, so that it cannot sense the real-time temperature of the low-pressure pipe. At this moment, if the temperature is too low, there is no doubt that the situation in Shandong will happen to the low-voltage tube (the opening of the air conditioning expansion valve cannot be reduced).

However, these conditions are basically out of repair, and a new air conditioning expansion valve must be replaced.

2. Evaporator temperature sensor failure

Because the evaporator temperature sensor fails. You should know that this part is used to detect the temperature of the evaporator surface, and then input the data to the automatic air conditioning control unit. When the ambient temperature is less than 2 ℃, the central air conditioner will stop running to avoid frost and thaw.

Therefore, when the temperature sensor of the evaporator of the air conditioner is invalid, of course, the corresponding temperature data information cannot be monitored, so that the low-voltage tube of the vehicle air conditioner freezes. At this time, a new sensor must be replaced.

As a result, the refrigerant can not circulate normally, and then frost occurs. The connecting pipe is intercepted. First check the pipe to see if it is bent. If there is, it indicates that the pipeline is intercepted, and the pipe dismantling can be considered. At ordinary times, we should also do a good job in the maintenance of the vehicle, which is very beneficial to the operation of the on-board air conditioner.