Car Speedometer Not Working? Let’s Find Out Why

car speedometer not working
Share Now

Table of Contents

One of the most important devices on the dashboard of your car is the speedometer. It gives you up-to-the-minute information about your car’s speed, enabling you to travel at the legal limit. Use the simple speedometer on your dashboard to keep track of your driving speed. This crucial tool guarantees that you maintain awareness and control while driving.

In certain vehicles, the speedometer takes the form of a gauge or needle that gradually rises as your driving speed increases. In modern cars, you may find a digital display that precisely shows your speed reading. This technological advancement ensures accurate and easy-to-read information while on the road.

On the other hand, a broken speedometer in your car might be a worry and a hassle. The reasons your car’s speedometer might not be working properly are covered in this article, along with methods you can take to identify and fix the problem. Let’s find them!

Importance of a Working Speedometer

Before diving into the potential causes of a malfunctioning speedometer, it’s essential to understand why it’s crucial to have a working one:

  • Safety: A speedometer’s principal function is to support you in maintaining a safe driving pace. Without it, you run the chance of unknowingly going over the posted speed limit, which raises the danger of collisions and moving violations.
  • Traffic Regulations: Driving without a functioning speedometer is illegal in many countries. You could face fines or other penalties if you’re caught without one.
  • Mechanical Health: A malfunctioning speedometer can sometimes be a symptom of a more significant mechanical issue in your vehicle. Addressing it promptly can prevent further damage.
  • Resale Value: When selling your car, potential buyers often consider the condition of critical instruments like the speedometer. A non-working speedometer could reduce your car’s resale value.

Common Reasons for a Non-Functioning Speedometer

Now, let’s explore the common reasons why your car’s speedometer may stop working:

  • Faulty Speed Sensor: The speed sensor is crucial to your vehicle’s speedometer system. It’s typically located on the transmission or wheel hubs and generates electrical signals sent to the speedometer to display your speed. A malfunctioning or damaged speed sensor can lead to inaccurate readings or a malfunctioning speedometer.
  • Broken Speedometer Cable: A cable connects the speedometer to the transmission in older vehicles. If this cable breaks or becomes damaged, the speedometer will stop working. Modern cars, however, use electronic sensors instead of wires.
  • Instrument Cluster Issues: Sometimes, the problem may be with something other than the speedometer but with the instrument cluster that houses it. Loose or damaged connections or circuitry within the collection can disrupt the speedometer’s operation.
  • Blown Fuse: A blown fuse in the vehicle’s fuse box can cause the speedometer to stop working. Fuses protect electrical components from overloads; if one related to the speedometer blows, the circuit is interrupted.
  • Vehicle Speed Sensor (VSS) Malfunction: The Vehicle Speed Sensor sends speed data to various vehicle systems, including the speedometer. If the VSS fails, it can affect the speedometer and other aspects of vehicle performance.
  • Wiring Issues: Damaged or corroded wiring in the speedometer circuit can lead to signal disruption, resulting in speedometer failure.
  • Instrument Panel Bulb Burnout: In some cases, a malfunctioning speedometer may be due to a burnt-out bulb that illuminates the instrument panel. When the bulb fails, it can affect the visibility of the speedometer’s needle.
  • Faulty ECM or PCM: The Engine Control Module (ECM) or Powertrain Control Module (PCM) plays a role in processing speed data and transmitting it to the speedometer. A malfunctioning ECM or PCM can lead to speedometer issues.

How to Diagnose a Non-Functioning Speedometer?

Although determining the cause of a broken speedometer can be difficult at times, you can follow these procedures to do so:

  • Check Other Gauges: Start by checking if other gauges in your instrument cluster function correctly. If all the gauges are not working, it could indicate a problem with the instrument cluster, such as a blown fuse.
  • Inspect the Speedometer Cable: If your vehicle is older and uses a cable-driven speedometer, inspect the cable for damage. It may need replacement if it’s broken or frayed.
  • Check the Vehicle Speed Sensor: Test the Vehicle Speed Sensor using a multimeter to ensure it’s sending the correct signals. Consult your vehicle’s service manual for guidance on how to do this.
  • Check for Fault Codes: Modern vehicles with onboard diagnostics (OBD-II) can provide error codes that may pinpoint the issue. Use an OBD-II scanner to check for trouble codes related to the speed sensor or instrument cluster.
  • Inspect Wiring and Connections: Visually inspect the wiring and connections in the speedometer circuit for damage or corrosion. Repair or replace any damaged components.
  • Check the ECM or PCM: If other methods don’t reveal the issue, have the ECM or PCM tested by a professional to ensure it’s functioning correctly.

Addressing a Non-Functioning Speedometer

Once you’ve determined what is causing your speedometer to malfunction, you can take action to fix the problem:

  • Replacement of the speed sensor: If the speed sensor is broken, a replacement may be necessary. Consult the repair handbook for your car or get a professional mechanic to assist you.
  • Cable Replacement (for older vehicles): If your car uses a speedometer cable and it’s damaged, replace it with a new one.
  • Instrument Cluster Repair: If the problem lies within the instrument cluster, consider having it repaired or replaced by a professional.
  • Fuse Replacement: If a blown fuse is the culprit, replace it with the correct rating in your vehicle’s manual.
  • Wiring Repair: Repair any damaged or corroded wiring in the speedometer circuit to restore proper functionality.
  • ECM or PCM Replacement (if necessary): If the ECM or PCM is faulty, consult a mechanic or dealership to replace the module.

Final Thoughts

Although a broken speedometer can be annoying, it must be fixed right away for legal and safety reasons. You can recognise the issue and take the necessary steps to fix it by being aware of the typical causes and using the right diagnostic techniques. Fixing wiring problems or replacing damaged parts are frequent solutions.

Let’s say you want more information about the diagnosis or repair procedure. If that’s the case, it’s essential to get professional help from a mechanic or automotive specialist to make sure your car’s speedometer is working properly and keeps you safe while driving.

Related Blogs

Scroll to Top