Your Prius speedometer display may not show reading mainly due to two possible reasons: faulty or broken vehicle speed sensor or malfunctioning ECU. The speedometer itself may have some faults. Besides, bad wiring or faulty fuse may also lead to such a problem.
Why Is My Prius Speedometer Display Not Working?
The function of a modern vehicle’s speedometer takes input from the Speed Sensor. Later, it sends that data to the Engine Control Unit (ECU). As the ECU is already programmed with the Prius’s gear ratios and stock tire height, it uses this data and sends the speed reading to the instrument cluster.
Your Toyota Prius’s speedometer display may not work due to various reasons. It can be an issue with the vehicle’s speed sensor or a fault with the ECU. These issues can cause the speedometer to go bad and the display may not work. In this section, we will be going through those issues.
Whatever may be the issue, you would want the display back as early as possible. This article addresses exactly that. As you dive in, you will be able to pinpoint the exact issue and fix the issue.
Broken “Vehicle Speed Sensor” or VSS
A fault with the Vehicle Speed Sensor can cause the speedometer display to go bad. Normally, the sensor works to indicate the speed of the vehicle. Besides, it regulates the flow of fuel and ignition timing. If the speed sensor has gone bad, you will see the Check Engine light turn on and realize that there is an issue.
Another symptom you might see when the speed sensor goes bad is the P0500 trouble code. The cruise system will be affected which may interrupt the way that the engine runs.
The ECU or Engine Control Unit is often referred to as the vehicle’s brain which monitors a multitude of activities. It sends essential vehicular telemetry data to the driver by making use of the instrument cluster.
If there is an issue with the ECU, it may cause the speedometer display to stop working. The speedometer itself will be affected as it might drop to zero. This is the result of the failure of the ECU being unable to send the speed telemetry data to the instrument panel.
If the wiring from the VSS is exposed, it can get wet and short out in very wet conditions. As a result, your Prius’s speedometer may no longer work, causing the display to go bad. Also, you might want to check for a blown fuse.
How to Get the Speedometer Display Back?
A quick diagnosis will help you find the exact cause of the faulty speedometer display. To get the display back, press the start button without stepping on the brake. Then press and hold the “info” button and at the same time, turn the headlights on and off three times.
The diagnostic screen should appear soon after that. Once it does, press the start button and do not step on the brake while doing so. The display should now come on and you will be able to turn the car off and start again with the display. Another option is the unplugging and replugging of the 12 V battery.
Why is my Prius not showing the speedometer?
If your Prius is not showing the speedometer, it is nothing to panic about. It is pretty common and getting a diagnosis will help your way out more easily than you would expect.
Normally, the most common reasons behind a Prius not showing the speedometer is the vehicle speed sensor (VSS), a malfunctioning ECU, or an electrical issue. The issue could be within the speedometer as well. Any of these issues will cause the speedometer display to go bad and not work.
Prius Speedometer Display Off
Your Prius speedometer display may suddenly turn off and won’t work again. This is a pretty common issue many Prius owners face. The most common cause behind is turning on the headlights while the dimmer wheel is turned down.
As a matter of fact, this is pretty common to happen as it is easy to turn down the dimmer wheel while the headlights are wheeled. Once you fix the issue, the display should come back
Frequently Asked Questions
- How long do you need to disconnect the car battery to reset the computer?
You need the battery to be disconnected for at least 15 minutes. This will allow the computer enough time to forget about the code before you reconnect the battery. The resetting process should be successful at this moment.
- How do you force a Prius to turn off?
To force a Prius to turn off, you need to insert the smart key into the key slot located in the dashboard. Then press and hold the power button. Lastly, removing the key from the slot will force the Prius to turn off
When the speedometer display of your Prius does not work, it can be frustrating. Such a situation also makes driving somewhat dangerous. In the meantime, you can make use of a speedometer app that gives a pretty accurate reading.