Why does the speedometer sometimes work and sometimes not?
1 Answers
When the speedometer in a car sometimes works and sometimes doesn't, it is necessary to check whether the speed sensor is damaged, check if the sensor plug is loose, check if there is a fault in the sensor drive mechanism, and check whether there are any fault codes in the vehicle's wheel speed sensor and ABS control unit system. The fault may also be caused by the speedometer itself inside the instrument panel or a loose instrument panel plug. The instrument panel can be diagnosed using a fault diagnostic tool to retrieve fault codes or perform an action test to determine if the issue lies with the speedometer itself. Below is more information about speedometers: 1. What is a speedometer: A speedometer, also known as a speed indicator. It indicates the vehicle's driving speed through the pointer on the speedometer. The speedometer displays instantaneous speed, not the total mileage. 2. How does a speedometer work: The speedometer's indication relies on the speed sensor, which is installed on the transmission. Different rotation speeds produce different pulse signals, which are then converted into pointer output, displaying the current speed. Regulations require that the speedometer display a slightly higher speed than the actual speed for safety reasons. 3. Actual difference: There is a formula in the national standard: 0 ≤ displayed speed - actual speed ≤ actual speed / 10 + 4. In simple terms, there are two meanings: First, the displayed speed must be greater than the actual speed; Second, the allowable error is "actual speed / 10 + 4".
