کارکرد دائمی فن‌های خنک‌کننده

Cooling fans running whenever the ignition is on, regardless of temperature. It is usually the system failing safe rather than an overheating engine — a module that cannot trust its temperature reading or its fan control defaults to full cooling, which is the right choice.

So the first thing to establish is whether the engine is actually hot. A fan at full speed on a stone cold engine is a default state, and the temperature gauge sitting normal while the fans roar is the clue. A genuinely hot engine with the fans running is the fans working, and the fault is elsewhere in the cooling system.

The routes to the default are a failed temperature sensor, a lost fan speed feedback signal, a welded fan relay, or a control module fault. A welded relay is distinguishable in seconds — it will keep the fans running with the ignition off, which nothing else does. Check the coolant temperature the module is actually reading before anything else, since a sensor reporting a false high explains the behaviour completely.