What Causes the Passat's Temperature Gauge to Light Up When the Engine Temperature is Not High?

[StZoe]

Passat's dashboard temperature warning light staying on indicates a fault in the engine cooling system. The specific reasons are as follows: Low Coolant Level: Insufficient coolant in the engine cooling system, which could be due to leaks at points such as the water pump, damaged hoses, or a cracked radiator. Thermostat Failure: The thermostat in the engine cooling system fails due to excessive water temperature, as it cannot open, obstructing the flow of coolant within the engine and causing the coolant temperature to rise excessively. Fan Malfunction: The cooling fan in the engine cooling system is not functioning properly, leading to inadequate cooling of the coolant, which results in elevated coolant temperature and triggers the temperature warning light. Engine Fault: Malfunction in the engine cooling system during water pump operation, where the pump does not rotate smoothly, causing poor coolant circulation and thus illuminating the temperature warning light.