Why does the Volkswagen Touran's fan keep running after the engine is turned off?
1 Answers
Reasons why the Volkswagen Touran's fan keeps running after the engine is turned off: 1. Faulty coolant temperature sensor. The most likely cause is internal aging of the sensor, leading to signal drift. Occasionally, the control unit may receive completely normal signals, but at other times, the data received may deviate from normal values, causing the control unit to log the fault and trigger the fan to run at high speed. 2. Wiring issues. Since the coolant temperature sensor is directly connected to the engine, poor contact, short circuits, or open circuits in the wiring can cause the control unit to lose the coolant temperature signal, resulting in a logged fault. Additionally, to protect the engine, the control unit may actively command the fan to run at high speed. 3. Engine control unit failure. The control unit is the central processor for calculating coolant signals. If the control unit malfunctions, even if the sensor outputs correct signals, the calculated results may vary widely, leading to a logged fault.