Volkswagen Temperature Light Flashing Red

When the Volkswagen (VW) temperature light comes on or starts to flash, you need to stop, allow the engine to cool down, and check the cooling level.  Follow this guide on how to check the VW engine coolant level.

 If your VW temperature light is flashing, the coolant level is low, or the coolant level sensor is faulty. On the other hand, if the temperature light is always on (not flashing), it usually means the engine is overheating.  Either way, do not drive if the coolant temperature light is flashing. If you decide to drive, make sure the engine is not overheating.

Sometimes, VW temperature light flashes intermittently. For example, the temperature light flashes when you start the car but stops flashing after the engine is warmed up or if the engine is restarted. If the car runs great with no overheating issues, the problem usually is electrical, such as a faulty temperature sensor mounted on the coolant reservoir.

Pull over as soon as it is safe and turn off the engine. Allow the engine to cool down, then check the engine coolant level. If the engine coolant level is low, add engine coolant.

Restart the vehicle and check if the temperature light has turned off. If the temperature light keeps flashing, check if the cooling fan is spinning by looking at it. Do not touch the cooling fan.

Possible Causes

Volkswagen temperature light for any of the following reasons:

• Defective coolant level sensor. 
• The coolant level is low.

Other possible but less likely causes include:

• Engine is overheating
• Damaged wire harness to a temperature sensor
• Faulty ECU
• Bad sender for the temperature sender.

Typically, when your VW temperature light stays on or is flashing, you will not get a DTC code if you read codes with a generic OBD-II scanner. Instead, use a VW OBD-II scanner. Follow this guide on how to diagnose VW engine problems.

The YOUCANIC Full System Scanner can read and clear fault codes through every vehicle’s control module.

Should I drive if the VW temperature light is flashing red?

No. Do not drive if the temperature light is flashing. If the engine overheats and you continue to drive, you will cause expensive damage to the engine. You may blow a head gasket, or the engine may seize up.

VW temperature light is most likely flashing due to a faulty temperature sensor, but there is no way of knowing what is wrong without diagnosing the problem. If it is an electrical issue, the car may run fine, but you need to get the car diagnosed first. If you are not sure, contact an auto mechanic. We do not recommend driving the vehicle, calling a mechanic, or asking for advice.

What does VW red coolant light mean?

If the red coolant light stays on when the engine runs, the Engine Control Unit (ECU) has detected a cooling system problem. The engine may have overheated, or a sensor is operating out of range. In rare cases, the VW red coolant light may flash or stay on due to an electrical problem, such as a faulty ECU or instrument cluster, but those problems are rare.

VW coolant light comes on, but the car is not overheating.

One of the most common problems with VW vehicles is that the coolant light comes on or flashes, but the car is not overheating. This problem is usually caused due to a faulty temperature sensor or a damaged wire harness.

VW temperature light comes up at the cold start but goes away after a restart.

You most likely have a low engine coolant level. After the engine is started and the coolant warms up, the coolant level on the reservoir can rise enough to turn off the temperature light.

If the coolant level is correct, replace the sensor on the engine coolant reservoir. In many cases, the sensor is integrated into the coolant reservoir and requires the whole reservoir to be replaced.

Read the fault codes with a VW scanner if the temperature light stays on. Also, check the voltage at the sensor connector. Typically, you should get 5 volts with the engine on.

Frequently Asked Questions

We hope you find the Volkswagen Temperature Light Flashing Red guide helpful. Check these troubleshooting and repair guides for more help on your Volkswagen.