What's the matter with the BMW 5 Series heating fan always turning?

after commissioning, it was found that the air conditioning refrigeration of the car was normal, but the air conditioning temperature, wind speed and air outlet mode could not be adjusted, and the air conditioning blower often turned after turning off the ignition switch. Detected by the fault detector (ISID), the current fault code 8129 is read, which means that the power supply of LIN bus is short-circuited to ground.

The reason of hot air from the outlet of BMW 5 Series: The air conditioning pipeline is long, which is greatly affected by the heat generated by the longitudinal engine, and the air in the pipeline is heated! Solution: try to park in the shade in summer; Turn on the air conditioner for a few minutes after starting!

The specific reasons for the hot air from the outlet of BMW 5 Series are:

1. It is possible that the external circulation mode is still on, allowing the air outside the car to convectively enter the car. At this time, the car does not feel the wind when it is stationary. However, when driving, due to the oncoming wind, the air outside the car will be blown in through the air conditioning outlet, and this oncoming wind will pass through the engine compartment and carry the heat of the engine cooling system and exhaust system into the car from the air conditioning distribution box.

because there will be air pressure, it will be blown in from the air conditioner outlet. In fact, this is because of hot air conduction. There is a warm air water tank in the middle of our instrument panel, which is only separated from the air duct by a layer of board, which will also heat the air in the air conditioning distribution box. Due to heat conduction, hot air will be convected from the air outlet, so hot air will be felt to come out.

2. The long air conditioning pipeline is greatly affected by the heat generated by the longitudinal engine, and the air in the pipeline is heated! Solution: try to park in the shade in summer; Turn on the air conditioner for a few minutes after starting! Therefore, it is a normal phenomenon that there is still hot air at the air outlet after the air conditioner is turned off, and it is not a fault.

(photo/text/photo: Ask the beast in question and answer) Mercedes-Benz S-class boundary M5 Li ONE Buick GL8 Tucki P5 Xpeng Motors P7 @219.