why is my Volkswagen Golf MK7 (2015-2019) temperature gauge fluctuating?

Solution

1. Preparation

• Gather tools such as an OBD-II scanner, multimeter, socket set, and coolant.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace the Coolant Temperature Sensor

1. Locate the coolant temperature sensor, typically near the thermostat housing.
2. Disconnect the electrical connector from the sensor.
3. Remove the sensor using the appropriate socket or wrench.
4. Install the new coolant temperature sensor, ensuring it is seated properly.
5. Reconnect the electrical connector securely.

3. Replace the Thermostat (if needed)

1. Drain the coolant from the system to a suitable container.
2. Remove the bolts securing the thermostat housing and lift it off.
3. Take out the old thermostat and replace it with the new one, ensuring the correct orientation.
4. Reinstall the thermostat housing and torque bolts to the manufacturer specifications (generally around 10-15 Nm).
5. Refill the cooling system with the appropriate coolant mixture, ensuring no air pockets remain.

4. Inspect and Repair Wiring

1. Examine the wiring harness and connectors associated with the coolant temperature sensor.
2. Repair or replace any damaged wiring or connectors to ensure a proper connection.
3. Use electrical contact cleaner to clean the connectors if necessary.