Polo 9n3 radiator fan stage 1 issue

[Filke]

Hello everyone,

Recently, I've noticed that the cooling fan (the single large one in the engine bay, right behind the radiator) on my Polo 9N3 2005 1.4 TDI is not working in first speed. However, after some time when the engine heats up, the fan turns on normally in second speed.

Even though the VCDS shows that both speeds are functional (Coolant Fan Stage 1: ON; Coolant Fan Stage 2: ON) and proper voltage is present at the connector wires (the connector has 3 wires), the fan does not physically spin in first speed.

I’ve seen that this is a common issue in VAG group cars from that era, so I’m wondering:
- Is there a separate control module (physically detached from the fan) that regulates the fan speed, making it possible to replace just that part?
- Or is it necessary to replace the entire fan assembly (since the control module, along with the fan motor’s electronics, is integrated into the fan itself and cannot be replaced separately)?

[Crasher]

Which year and engine plus AC or not?

[Filke]

Engine is 1.4 TDI 59Kw BNV from 2005 with manual AC. It has just one radiator fan the same one for engine cooling and AC. Fan has 3 wires and 8 blades.

[Crasher]

It is VIN specific