What Causes No Signal from the Engine Speed Sensor?

1 Answers
VanAnnie
07/30/25 12:48am
The reasons for no signal from the engine speed sensor include: excessive distance between the sensor and the target wheel; short circuit or open circuit in the sensor wiring; or sensor damage. The specific solutions are as follows. Measure the resistance between the two terminals of the sensor. This resistance should be between 0.7 and 1.2 kiloohms: If the resistance is outside the specified range, it indicates that the sensor is damaged and should be replaced. If the resistance is within the specified range, continue to check whether there is a short circuit to ground, a short circuit to the positive terminal, an open circuit, or mutual short circuits between the wires in the sensor-to-engine control unit wiring. Repair any issues found promptly. If the problem persists after eliminating wiring faults, the speed sensor should be replaced. The speed sensor uses a magnetoresistive element as the sensing component and is a new type of speed sensor. Its core component employs a magnetoresistive element for detection, combined with a new signal processing circuit that reduces noise and improves functionality. Compared with the output waveforms of other types of gear speed sensors, the measured speed error is minimal, and the linear characteristics show excellent consistency. The sensing object is magnetic or magnetically conductive material. When the measured object has protrusions (or depressions) made of magnetic or magnetically conductive material, the sensor outputs a pulse signal related to the rotational frequency as the object rotates, enabling speed measurement or displacement detection.
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