There are several common causes for a speedometer to stop working. Typically, these malfunctions are caused by an issue with a car's wiring, a broken gear in the speedometer system, a speed sensor issue or a faulty engine control unit (ECU).Continue Reading
According to the experts at Seva Call, a faulty speed sensor is the most likely culprit in the case of a malfunctioning speedometer. Often covered under warranty, the speed sensor is located near the front axle and calculates the speed of the vehicle.
Another common and easy-to-fix issue could be a broken gear on the speedometer unit itself. Autos.com suggests that after diagnosing an issue with the speedometer unit, the vehicle owner can purchase replacement components from the dealership where the car was purchased, at certain body shops or on the Internet.
A malfunctioning speedometer may also be due to damaged wiring. Wiring is vulnerable to water damage and can cause fuses to blow. If the problem appears during wet weather especially or if the car has been exposed to excessive water, there is a good chance that this could be the issue.
Lastly, many automobile problems can be traced back to a malfunctioning ECU, which is the main computer that manages many of the car's processes. If the ECU is not working, it is possible that it is preventing the speed sensor from reporting the speed to the speedometer. A broken ECU breaks this link between the two components and could cause an issue.Learn more about Car Parts & Maintenance
The most likely reason a speedometer stops working is a broken gear. Finding the problem involves removing the speedometer assembly from the vehicle and locating the problem piece. Replacements are available at dealerships, auto parts stores and online.Full Answer >
The speedometer and tachometer are parts included in a vehicle's instrument panel cluster. The odometer and fuel gauge are also present as well as dashboard indicators, such as the emergency brake, check engine, gearshift position and seat belt lights. Other dashboard indicators include lights to warn for low tire pressure and oil pressure as well as any problems with the vehicle's airbags.Full Answer >
The calibration of a speedometer is based on the torque that the magnetic field creates and takes into account the ratios of the gears in the drive cable, the final drive ratio in the differential and the diameter of the tires. A large change in the size of a car's tires is one of the most common ways a speedometer's accuracy is compromised because it affects how far the car goes with each revolution of the tires.Full Answer >
When problems occur with the speed sensor, the vehicle does not send the right signal to the speedometer, regulate fuel properly, operate cruise control or regulate ignition timing correctly. Problems with the speed sensor are the result of wear and tear and have a direct effect on the performance of multiple systems in the vehicle. The most common symptom of a malfunctioning speed sensor is a malfunctioning speedometer.Full Answer >