Why does the tachometer stop working but the car can still run?
2 Answers
The tachometer stops working but the car can still run due to the following reasons: a malfunction in the vehicle's instrument cluster speedometer; a failure in the vehicle's wheel speed sensor; a malfunction in the vehicle's mileage sensor; or foreign objects stuck inside the gauge preventing movement, which can be resolved by disassembling the gauge and removing the obstruction. Below are the relevant details: 1. Principle: The tachometer is usually located within the instrument panel, symmetrically placed alongside the speedometer. It operates based on magnetic principles, receiving pulse signals generated when the primary current in the ignition coil is interrupted, and converting these signals into a displayable RPM value. 2. Function: The engine's RPM is related to the number of work cycles per unit time or the effective power output of the engine, meaning the engine's effective power varies with RPM. Therefore, when specifying the engine's effective power, the corresponding RPM must also be indicated.
Seeing the tachometer not moving but still being able to drive, I think this might involve several common issues, mainly problems with the components related to the tachometer, not the engine itself. For example, the tachometer sensor might be broken or have poor contact. This sensor detects the engine speed, and if it fails, the signal won’t reach the dashboard. Or there could be a circuit fault in the dashboard itself, such as loose wiring or a blown fuse, since the tachometer is electronically displayed. Another possibility is that the engine control unit sometimes transmits incorrect data, causing the tachometer to not respond. However, the car can still drive normally because the engine’s actual operation is mechanically controlled. I must remind you, even if you can drive, don’t take it lightly. Ignoring tachometer issues might lead to misjudging the engine’s condition, such as hidden fuel pump problems or battery faults, which could result in a breakdown or increased fuel consumption. It’s best to go to a professional repair shop as soon as possible to check the sensor and wiring for safety. For a temporary fix, you can drive the car to a stable location and check if the dashboard connection wires are loose.
