Also known as antifreeze, coolant helps maintain a stable engine temperature. Part of the red warning light family on the dashboard, it’s an indicator of proper operation of the engine cooling system.
But how does it work?
Why does the coolant warning light turn on?
And how can you turn it off?
Are you looking for a car scanner ?
- My model is not in the list
I don't have any lights on
What is coolant used for?
Coolant helps the engine maintain the right temperature, around 100°C.
It's a mixture of water and ethylene glycol that prevents freezing at low temperatures and overheating at high temperatures.
How coolant works
Engine temperature is regulated by a thermostat, usually located near the cylinder head.
When the engine is cold, the thermostat remains closed and forces the coolant to circulate only within the engine.
Once the engine reaches operating temperature, the thermostat opens to push the accumulated coolant into the radiator. A small amount of coolant then replaces the volume of water in the engine to maintain an optimal temperature.
The cooling circuit: how does it work?
Coolant flows through the engine cooling circuit to keep the engine at the ideal temperature. Warming up the engine quickly at startup helps reduce fuel consumption.
This warm-up is done by circulating coolant only through the engine.
The thermostat opens the main circuit and closes the small one. Coolant then flows through the radiator and partly through the expansion tank, keeping the engine at a proper temperature.
What is the coolant temperature sensor used for?
The coolant temperature sensor, as the name suggests, measures the coolant’s temperature. If the temperature is too low or too high, it immediately alerts the driver. It is therefore a key component of the cooling system, as the engine’s performance depends on temperature regulation.
Why is my coolant warning light on?
The warning light indicates whether the engine cooling system is functioning correctly. If it appears on your dashboard, it usually means the engine is either too cold (rare) or too hot (more common).
Unfortunately, when the light turns on, it often signals a coolant leak. If this happens while driving, pull over immediately.
This means the engine is overheating, and continuing to drive could cause severe damage.
This is why it's important to regularly check your vehicle’s coolant level.
Are you looking for a car scanner ?
Conclusion
The coolant warning light alerts you when the engine is not at the correct temperature. It's a serious warning and should not be ignored. If it lights up while driving, don’t take the risk — stop your vehicle as soon as possible.