What is the Inspection Method for the Crankshaft Position Sensor?
3 Answers
The inspection methods for the crankshaft position sensor are: 1. Resistance check of the crankshaft position sensor: Unplug its wiring connector, use a multimeter to measure the resistance between each terminal on the sensor, which should comply with the specifications in the attached table. Otherwise, the sensor should be replaced; 2. Output signal check: Unplug the wiring connector of the crankshaft position sensor. When the engine is rotated, there should be a pulse signal output between the terminals. If there is no pulse signal output, the sensor needs to be replaced; 3. Gap check between the sensor coil and the signal rotor: Use a feeler gauge to check the air gap between the signal rotor and the protrusion of the sensor coil. The gap should be 0.2 to 0.4mm. If the gap does not meet the requirements, adjustment or replacement is necessary.
I recently learned how to check the crankshaft position sensor myself. This component is located near the engine and primarily measures the rotational position of the crankshaft. If it fails, the car may not start or could stall. My usual method is to first turn off the engine and remove the key to ensure safety, then locate the sensor, which is typically near the engine block or behind the pulley. Check if the connector is loose or corroded, give it a gentle shake, and if it's loose, just plug it back in securely. Next, set the multimeter to the resistance mode, unplug the connector, and measure the resistance between the sensor's pins. The normal range should be between 500 and 1500 ohms. If the reading is too low or shows infinity, it needs replacement. I've also tried starting the car to see if the check engine light comes on. If it does and shows an OBD code like P0335, it usually confirms the issue. To prevent problems, avoid moisture getting into the connector, be careful when washing the car, and note that the sensor is sensitive to vibrations—misalignment during installation can cause errors, so avoid using excessive force when installing. These methods have saved me a lot on repair costs, but if you can't fix it yourself, it's best to take it to a professional shop promptly to avoid any driving issues.
I've been repairing cars for over a decade, and checking the crankshaft position sensor isn't difficult—the key is knowing where to focus. This sensor is crucial for engine control; when it fails, the engine speed goes haywire. First step is visual inspection: feel the sensor while the engine is running—if it's too hot, there might be an internal short circuit. Next, test the voltage: set the multimeter to DC voltage mode and measure the output signal while starting the engine. It should fluctuate between 0-5 volts; if it stays at 0 volts, it's dead. Pay special attention to the connector—90% of issues stem from there: rust, water damage, or broken wires. Clean it thoroughly and check the results. Diagnostic tools are even better—connect to the onboard computer and scan for codes. If you see issues like abnormal frequency or insufficient signal, address them accordingly. The sensor position must be precise—use a ruler to ensure alignment error doesn't exceed 1mm. If a new sensor doesn't solve the problem, check if the crankshaft reluctor ring is damaged. Follow the steps from easy to hard, and prioritize safety—never work on live circuits.
