2018 Subaru WRX STI Speedometer Isn't Working

Diagnosing the Causes of a Non-Functional Speedometer in Your 2018 Subaru WRX STI and How to Fix It

Find Repair Location
Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
35% chance it's the
Vehicle Speed Sensor (VSS)
0%
28% chance it's the
Speedometer
0%
23% chance it's the
Electrical Issue
0%
14% chance it's
Something else
The most common reasons a 2018 Subaru WRX STI speedometer isn't working are the vehicle speed sensor (VSS), a faulty speedometer, or an electrical issue.
  • Vehicle Speed Sensor (VSS): A faulty vehicle speed sensor can result in inaccurate speed readings and erratic transmission shifting.
  • Speedometer: A faulty speed sensor or a broken connection in the speedometer circuit can result in inaccurate speed readings.
  • Electrical Issue: A blown fuse or a short circuit in the wiring can cause various electrical issues in the vehicle's systems.
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.

What are the steps to diagnose a non-functioning speedometer in a 2018 Subaru WRX STI?

To effectively diagnose a non-functioning speedometer in a 2018 Subaru WRX STI, begin with a systematic approach that prioritizes simpler solutions before delving into more complex diagnostics. Start by checking the fuse associated with the speedometer in the fuse box, as a blown fuse is a common and easily fixable issue. If the fuse is intact, proceed to inspect the speed sensor located on the transmission; ensure there are no visible damages or loose connections that could disrupt its function. Next, examine the wiring and connections linked to the speed sensor for any signs of wear, corrosion, or disconnections, as these can significantly impact performance. If these preliminary checks do not resolve the issue, testing the speedometer cluster may be necessary, which could involve diagnostic tools or professional assistance. Lastly, consider the vehicle speed sensor (VSS) as a potential source of the problem; if all else fails, testing or replacing the VSS might be required to restore proper speedometer functionality. By following this structured diagnostic approach, you can efficiently identify and address the underlying issues affecting your speedometer.

What are the common problems that could cause the speedometer to stop working in a 2018 Subaru WRX STI?

When the speedometer in a 2018 Subaru WRX STI ceases to function, it can be frustrating for any driver. One of the most frequent culprits is a faulty vehicle speed sensor, which is responsible for relaying speed data to the speedometer. If this sensor malfunctions, it can result in either inaccurate readings or a complete failure of the speedometer. Another possibility is a defective speedometer gauge itself; if the gauge is damaged, it may not display speed correctly or at all. Additionally, electrical issues such as blown fuses or damaged wiring can disrupt the power supply to the speedometer, leading to operational failures. Problems within the instrument cluster, where the speedometer is housed, can also cause it to stop working properly. Lastly, if the vehicle's computer or electronic control module (ECM) is experiencing issues, it can significantly impact the speedometer's performance. By understanding these common problems, DIY enthusiasts can better diagnose and address the speedometer issues in their Subaru WRX STI.

How urgent is it to address the non-functioning speedometer in a 2018 Subaru WRX STI?

Addressing a non-functioning speedometer in your 2018 Subaru WRX STI is not just a matter of convenience; it is an urgent necessity. The speedometer plays a critical role in ensuring that you are driving within legal limits, and without it, you risk unknowingly exceeding speed limits, which can lead to hefty fines or even the suspension of your driving privileges. Moreover, the safety implications cannot be overstated; an inaccurate speed reading can result in driving too fast or too slow, significantly increasing the likelihood of accidents. Additionally, the speedometer is linked to various vehicle systems, and neglecting this issue could lead to further complications that affect your car's overall performance and drivability. Lastly, if you plan to sell your vehicle in the future, a malfunctioning speedometer can deter potential buyers and diminish your car's resale value. Therefore, it is crucial to address this issue promptly to ensure your safety, compliance with the law, and the longevity of your vehicle.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.

Troubleshooting 2018 Subaru WRX STI Speedometer Issues