VW Temperature Light Flashing Red

Vehicle:   Volkswagen
Difficulty: ⚫⚫⚪⚪⚪
DIY Cost: $30-$200
Est. Time: 10 min - 1 hr

When the Volkswagen 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.

VW temperature light flashing

If your VW temperature light is flashing, it means 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 stays on or is flashing. If you do decide to drive, make sure the engine is not overheating. 

Sometimes VW temperature light flashes intermittently. For example, the temperature light flashes when you first 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. 

VW temperature light flashing red

 

Pullover as soon as it is safe to do so 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.

Check vw engine coolant level if temperature gauge flashes

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

Common causes of VW temperature light flashing

Volkswagen temperature light for any of the following reasons:

  • Defective coolant level sensor. 
  • 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 temp 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

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

VW temperature light flashing

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 most likely is 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, see an auto mechanic. 

We do not recommend that you drive the vehicle, call a mechanic, and ask for advice. 

What does VW red coolant light mean? 

If the red coolant light stays on when the engine is running, it means that 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 some rare cases, 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, which is 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. 

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

By YOUCANIC Automotive Experts
Nov 2020
VW Temperature Light Flashing Red When the Volkswagen 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.