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Cooling system · DashRead · Car Copilot

Coolant warning light on

A coolant warning light on your car means the cooling system is low or overheating, and if the engine is running hot you are one step from real engine damage. As with any overheating, the mandatory rule is never open a hot radiator cap. Show SightLine the dashboard and reservoir and it helps you tell a simple low-coolant top-up from a stop-now overheat.

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Steps to fix coolant warning light on

  1. Check the temperature gauge: if it is climbing into the red, treat this as overheating — pull over and shut the engine off now.
  2. If the temperature is normal and it is only a low-coolant reminder, you can plan to top up the coolant soon at the reservoir.
  3. MANDATORY SAFETY: never unscrew the radiator or coolant cap while the engine is hot — scalding pressurized coolant can burn you badly.
  4. Wait until the engine is fully cool (at least 20 minutes, hood open) before opening any cap or adding coolant.
  5. Top up only the plastic overflow reservoir to its marked line with the correct coolant when cool, and look underneath for puddles that hint at a leak.
  6. If the light keeps returning or you find a leak, do not keep driving on it — have a mechanic pressure-test the cooling system.

Safety first: DashRead has no OBD scanner, so it never reads or guesses a trouble code — it works from what it can see and what you tell it. A red oil-pressure, temperature, or brake light, or a flashing check-engine light, means stop now. When in doubt about whether it's safe to drive, don't drive — see a mechanic.