2018 Toyota Prius C Radiator Fan Isn't Working

Diagnosing the Causes of a Non-Functional Radiator Fan in Your 2018 Toyota Prius C and How to Fix It

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Reviewed by
Aisha
Written by RepairPal Car Genius
Updated January 14, 2025
0%
34% chance it's the
Fan Motor or Clutch
0%
28% chance it's the
Fan Relay or Fuse
0%
23% chance it's the
Temp Sensor or Fan Control Module
0%
15% chance it's
Something else
The most common reasons a 2018 Toyota Prius C radiator fan isn't working are the fan assembly, the fan clutch, or the coolant temperature sensor.
  • Fan Motor or Clutch: A faulty fan motor or a malfunctioning fan clutch can result in inadequate cooling, causing the engine to overheat.
  • Fan Relay or Fuse: A faulty fan relay or blown fuse can prevent the cooling fan from operating, leading to engine overheating.
  • Temp Sensor or Fan Control Module: A faulty temperature sensor or fan control module can result in incorrect readings, causing the engine to overheat or the cooling fan to operate improperly.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2018 Toyota Prius C radiator fan isn't working?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

The bad thermostat can cause two different sets of problems, depending on whether it's stuck open or stuck closed.

A thermostat that is stuck open can cause the engine to run colder than normal and turn on the check engine light. It may also cause poor fuel mileage and the heater to blow cool air.

A thermostat that is stuck closed will cause the vehicle to overheat. If a new thermostat doesn't resolve engine temperature problems, the cooling system needs to be checked for other issues.

» LEARN MORE: Signs of a bad thermostat, and how to fix it

When the engine coolant temperature sensor fails, it will send inaccurate information to the vehicle’s computer, causing the computer to react to false operating conditions. This will cause the engine to consume more fuel than normal, depleting fuel mileage, and causing black, sooty smoke from the engine under moderate to heavy acceleration. The check engine light will illuminate, and on-board diagnostic trouble codes may be stored for exhaust and emission system failure, fuel delivery system failure, and engine cooling system failure. Overheating may also occur, as the coolant sensor may be leaking fluid out of the engine, creating a an air pocket in the system.

What are the steps to diagnose the non-functioning radiator fan in a 2018 Toyota Prius C?

When diagnosing a non-functioning radiator fan in a 2018 Toyota Prius C, it's essential to adopt a systematic approach that prioritizes simpler checks before moving on to more complex diagnostics. Begin by examining the fuse associated with the radiator fan; a blown fuse is a common and easily fixable issue that can halt fan operation. If the fuse is intact, proceed to inspect the relay that controls the fan, as a faulty relay can prevent the fan from activating. Next, test the radiator fan motor itself to ensure it is operational; if the motor is defective, it will need replacement. Additionally, check the wiring for any signs of damage or loose connections, as these can disrupt the fan's functionality. Utilizing a diagnostic scanner to scan for error codes related to the cooling system can provide further insights into the problem. Finally, monitor the temperature gauge while the vehicle is running; if the engine overheats without the fan engaging, this could indicate a significant issue with the radiator fan system. By following this structured diagnostic approach, you can effectively identify and resolve the issue with your Prius C's radiator fan.

What are the common causes for the radiator fan not working in a 2018 Toyota Prius C?

When diagnosing the radiator fan issue in a 2018 Toyota Prius C, it's important to systematically evaluate several common problems that could be affecting its performance. Start by checking the fan motor, as it may be faulty due to wear or electrical malfunctions, which can prevent it from operating correctly. Next, inspect the fuses associated with the fan circuit; a blown fuse can easily interrupt power and stop the fan from working. Additionally, consider the temperature sensor, as a malfunction here may fail to trigger the fan when the engine reaches the required temperature. Wiring issues, including damaged or loose connections, can also hinder the fan's operation, so a thorough inspection of the wiring is essential. Finally, ensure that the coolant level is adequate, as low coolant can prevent the engine from reaching the temperature needed to activate the fan. By addressing these potential issues, you can effectively troubleshoot and resolve the radiator fan problem in your Prius C.

How urgent is it to repair the non-working radiator fan in a 2018 Toyota Prius C to avoid engine overheating?

Repairing a non-working radiator fan in a 2018 Toyota Prius C is an urgent matter that should not be overlooked. The radiator fan is essential for regulating the engine's temperature by dissipating heat generated during operation. When this component fails, the engine is at risk of overheating, which can lead to severe damage, including blown head gaskets and damaged pistons. Additionally, overheating can compromise the integrity of engine oil and coolant, leading to further complications and costly repairs. For DIY enthusiasts, addressing this issue promptly not only safeguards the engine's health but also enhances the vehicle's overall performance. Ignoring the symptoms of a malfunctioning radiator fan can escalate into a safety risk, making it imperative to diagnose and repair the problem as soon as possible. Taking action now can save time, money, and prevent the hassle of more extensive repairs down the line.

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2018 Toyota Prius C Radiator Fan Issues & Repair Guide