Speedometer is not working

My speedometer is not working right. On some occasions it will jump to the right speed.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
You have an electronic type speedometer in your truck. The speed sensor in the rear axle is the sensor that allows the speedometer to read the speed.

You will need to have the computer scanned to see if the speedometer is getting a speed signal from this sensor.

If the speedometer is receiving a signal, then you will need to replace the speedometer.

If there is no signal, then replace the sensor in the top center of the rear end.

I would suggest having a qualified mechanic inspect your speedometer issue.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

Your speedometer is directly linked to the speed sensor — meaning if anything goes wrong with the vehicle speed sensor, it`ll lead to a speedometer failure. Whether you have hall effect or digital speed sensors, here are some signs of a bad sensor that may accompany your erratic speedometer needle: Transmission issues.
The speed sensor is located in the rear axle. The speed sensor is removed from the rear axle housing. The new speed sensor is installed into the axle housing. The speed sensor connector is connected.
The speed sensor is a small device that tells your car`s speedometer how fast you`re going. It plays a role in your car`s transmission and cruise control systems.
The speedometer sensor is located inside the transmission and attached to a driveshaft, which impacts multiple functions of the car.
The most common causes of a speedometer that stopped working include are a faulty speed sensor, a broken gear on the speedometer, damaged wiring, or a faulty engine control unit.
A wheel speed sensor (WSS) or vehicle speed sensor (VSS) is a type of tachometer. It is a sender device used for reading the speed of a vehicle`s wheel rotation.
Typically the speed sensor mounts on the transmission and gets its signal from a toothed gear inside the transmission housing. The sensor has an electric current running and a magnetic tip that sits very close to the teeth on the gear.
In speedometer controllers of this type that use a detection signal from a vehicle speed sensor, the detection signal from the vehicle speed sensor is transmitted through a powertrain control module (hereinafter referred to as “PCM”).
One of the most common signs of a bad speed sensor is abnormal automatic transmission operation. If the VSS is faulty, the transmission may exhibit symptoms such as delayed shifts, hard shifts, and limited gear operation.
signs of a failing abs speed sensor

it may also turn on the traction and stability control warning lights, if the car has those systems. occasionally, the speedometer may stop working, as well.

Faulty Fuse/Bad Wiring: In very wet conditions, it is possible for exposed wires to get wet and short out, causing a fuse to blow. When the fuse for your speedometer stops working, it can cause the speedometer to drop to zero.
The instrument cluster fuse, also known as the dashboard fuse, is responsible for powering the dashboard gauges and displays. If this fuse is blown or damaged, it can cause the gauges and displays to stop working or function improperly.
Common signs include harsh or improper shifting, cruise control not working, and the Check Engine Light coming on.
signs of a failing abs speed sensor

it may also turn on the traction and stability control warning lights, if the car has those systems. occasionally, the speedometer may stop working, as well.

Common signs include harsh or improper shifting, cruise control not working, and the Check Engine Light coming on.
The output speed sensor is also known as the vehicle speed sensor in a vehicle. It transmits a signal to the transmission control unit, informing it of the vehicle`s speed.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Windshield wipers stopped working. They’ll suddenly stop working then suddenly start working again. Has been happening for a week.
ANSWER : The problem you are describing likely stems from an intermittent electrical fault in the wiper circuit. The windshield wiper system uses a small electric motor to move the wiper arms that you see on the windshield. That electric motor is controlled through a switch, relay, fuse, and wiring. One, or more, of those electrical components has failed although it is also possible that the mechanical arms are binding (seized, if the lubricant has dried out) thus causing the electric circuit to the motor to overload. Regardless of the underlying fault, if you request a non functioning wiper diagnostic/repair, the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Read Full Q/A … : Speedometer is not working

My dash board don’t work my front light work when I change my light into high beam and my back window won’t go down
ANSWER : As unfortunate as it is, your vehicle would be considered flood damaged. Diagnosing electrical problems in a flood damaged vehicle is nearly impossible. This would take many hours or even days to determine which wiring harnesses and circuits have been affected. Then nearly all of the wiring under the dash would likely require replacement as well as many sensors and switches. On a BMW vehicle, the amount of wires and switches are likely more than that of a lower end vehicle. Due to the inefficiency in cost, you would likely be able to purchase another BMW like yours for less than what it would cost to fix your car. Many insurance companies would consider this type of damage to total out the vehicle unfortuantely.

Read Full Q/A … : Speedometer is not working

Gas gauge isn’t working. Sometimes the speedometer and the temperature gauge doesn’t work. Limited lights around gauges and radio.
ANSWER : Hi there. The dashboard lights are burned out in the dash and the dimmer switch could be worn causing the lights to be weak. The gauges that seldom fail to work is most likely a loose wire in the dash panel. The fuel gauge that is not going to E when shutting off the car has a damaged rheostat within the sending unit. The sending unit is in the fuel tank attached to the fuel pump. If you need further assistance with your gauges not working, then seek out a professional, such as one from Your Mechanic, to help you.

Read Full Q/A … : Speedometer is not working

All dashboard lights and tail lights do not work after driving through a lot of snow. Headlights work. And brake lights work.
ANSWER : Hello. We’ll be happy to help you. There are a few things that I recommend checking to discover why your lighting system is malfunctioning. The headlight dimmer switch should be checked. Along with the wiring harness above the right front tire behind the fender well cover. Also
the main fuse under the hood should be inspected because other people with your particular vehicle have had similar lighting issues if that fuse goes bad. It will be a great idea to check the rest of the fuses in that area too while checking the main fuse. Once the fuses are checked inside of the main fuse box then I would check the fuses inside of their interior fuse box. The interior fuse box should be located on the driver side of the dashboard near where your legs would be. If you need more assistance with repairing your vehicle please keep in mind that our organization provides Mobile Mechanics who can help you diagnose and repair your vehicle, all at competitive rates.

Read Full Q/A … : Speedometer is not working

Engine check light on and cruise control not working, but speedometer works
ANSWER : Hi there, thanks for writing in. Usually the P0717 OBD-II error code is associated with a speed sensor problem inside the transmission. This part helps to monitor the cruise control along with the speedometer. If the sensor is damaged or has a loose fitting wire harness, it will disable the cruise control first as a safety measure; but allow the speedometer to work in many cases. The best way to know for sure is to contact one of our mechanics to replace your speed sensor, or inspect the vehicle for cruise control issues.

Read Full Q/A … : Speedometer is not working

My AC does not always work. If I fiddle with the blower knob I can ususally get it to work on the lowest setting.
ANSWER : Hi There,
It sounds like you may have a faulty blower motor resistor. The highest speed setting may still work because in most cars in the highest fan speed settings the current bypasses the blower motor resistor. In some cars, if the resistor is failed, the fan may stop working completely. Another reason a blower motor resistor may fail is when the blower motor has a mechanical problem or when a foreign object jams the blower motor fan blade and prevents it from spinning freely. This leads to increased current through the resistor and causes it to overheat and fail. I would suggest having an expert from YourMechanic come to your location to diagnose your system to determine what may be causing the fan not to work properly.

Read Full Q/A … : Speedometer is not working

Car starting sometimes, sometimes have to jump, speedometer and tach working but all other gauges not working 2003 GMC Yukon
ANSWER : Hi there – check fuses first, but it sounds like you might have a problem with your digital dash, and possibly a wiring issue that is draining your battery overnight. The lack of gauge function is is a high failure rate circuit board issue, but there are rebuilder service companies out there that specialize in this work. The battery drain issue maybe be a different problem, but can be tracked down as well. This problem can be diagnosed by connecting an ammeter to the positive (red) battery cable, observe the current drain (likely less than 1 amp), then, one at a time, remove each fuse, check to see if the current drain has dropped to near 0, then reinsert the fuse. This process should identify the faulty circuit in most cases. The specific components on that circuit can then be checked for current drain problems. A professional mechanic, like YourMechanic, can come to your location, and perform this procedure for you, and replace/repair the failing component.

Read Full Q/A … : Speedometer is not working

My speedometer, rpm gauge and fuel gauge are not working; possible gear slipping and high rpm.
ANSWER : Hi there. For the electrical issues on the dash that are not working properly, I recommend that you have your battery check and loaded. The battery could have 12.6 volts, but if a cell is burnt or damaged, the battery will not hold a load causing issues with the electrical system to your vehicle. If the battery is low on charge and or fails the load test, then I recommend replacing the battery with a new one if it is more than a year old. Batteries in a vehicle usually last about 2 to 3 years without having any issues. If you need further assistance with your gauges not working properly, then seek out a professional, such as one from Your Mechanic, to help you.

For the jerking feeling when shifting, check the transmission fluid and see if it’s full and red in color. If the fluids are low, top them off and check the condition of the shifting issue. Another possibility that can cause the transmission to jerk into gear is the transmission or engine mount could be loose or damaged. If the transmission is still having an issue with shifting, then I recommend seeking out a professional, such as one from Your Mechanic, to help you with your transmission jerking in gear.

Read Full Q/A … : Speedometer is not working