Where is the RPM Sensor Located?
2 Answers
The engine RPM sensor is installed on the rear crankshaft oil seal, with a small hole on the side of the cylinder block. Below is a detailed introduction to the RPM sensor: 1. The engine RPM sensor is an inductive sensor that captures the engine speed and the precise angular position of the crankshaft for input into the system. A separate signal wheel for the engine RPM sensor is mounted on the flywheel; 2. The signal wheel is designed as a wheel with multiple tooth segments, divided into a total of 60 segments. Each time the signal wheel passes the sensor, an alternating voltage is generated, the frequency of which varies with the speed. The frequency indicates the level of RPM; 3. To identify the crankshaft position, there is a gap between two tooth segments on the signal wheel. The engine RPM sensor is used to identify the engine speed. Together with the Hall sensor, it identifies the top dead center of the first cylinder's ignition, thereby determining the fuel injection timing and ignition timing.
With years of hands-on experience in the garage, I've got the crankshaft position sensor's location down pat. It's typically mounted near the engine's crankshaft or above the transmission flywheel. My ride is a classic Japanese sedan, where it's tucked away on the lower left side of the engine bay—accessible only with a lift or by sliding underneath, specifically hidden beside the oil filter. Last month, while helping a neighbor fix their car's erratic RPM issue, the sensor on their Citroën was positioned behind the exhaust manifold, clogged with dust causing unstable readings—replacing it did the trick. Don't underestimate this small component; its placement varies by vehicle—pickups might have it upfront, SUVs beneath the suspension. Mishandling without knowing the exact spot could damage wiring, worsening the situation. Always consult the vehicle manual or team up with a knowledgeable buddy first.
