Coolant temperature warning light: meaning and what to do

Coolant temperature

The exact symbol can vary between makes and models. Also check the message displayed by the vehicle.

How urgent is it?

Stop safely for an overheating warning; allow the engine to cool.

How to recognise it

Thermometer above waves.

What it can mean

A red warning can indicate overheating. On some cars, the same symbol in blue indicates a cold engine.

What to do

Stop safely and allow the engine to cool. Never open a hot expansion tank; follow the message and handbook.

Before clearing the light or codes

Photograph the dashboard message and save all codes, the reporting module, fault status and freeze-frame data. Clearing can remove useful evidence without repairing the cause.

Useful terms

From warning light to inspection

A warning light can have many causes. The example codes below have NOT been scanned from your vehicle.

For red warning lights, follow the safety and stop instructions; do not delay assistance for online analysis.