What is the measurement method for the camshaft position sensor?
2 Answers
The measurement method for the camshaft position sensor is as follows: 1. Unplug the connector of the camshaft position sensor, turn the key to the second position, and use a voltmeter to measure and confirm that the power line has voltage output; 2. Connect one wire of the voltmeter to the confirmed power line, and connect the other wire to the remaining two wires to measure which one has voltage (this is the ground wire), leaving the remaining one as the signal wire; 3. Turn off the key, connect the signal wire, plug back the connector, and start the engine. The function of the camshaft position sensor is to collect the position signal of the valve camshaft and input the signal to the electronic control unit to determine the ignition timing and fuel injection timing.
I've always considered testing the camshaft position sensor as a fundamental skill in car repair. When doing it myself, I usually start by disconnecting the connector. I set the multimeter to the voltage range and check the power supply pin, which should typically have 5V or 12V—this is the power coming from the ECU. If it's lower, it indicates a wiring issue. Next, I test the signal pin; during ignition, it should show pulse fluctuations. If the multimeter readings aren't clear, I use an oscilloscope to check if the waveform is clean. If the voltage is normal but there's no signal, the sensor itself might be faulty. In that case, I remove it and measure the resistance with the multimeter in the ohmmeter mode—reference values usually range between 200 and 1000 ohms, which can be found in the manual. Don't forget to check the resistance of the ground pin—it should be close to zero; otherwise, there might be a loose connection or a short circuit, which are common issues. Key point: A faulty sensor can cause unstable idling or difficulty starting the engine. Early detection can save you from costly major repairs, and regular cleaning of dust during maintenance also helps.
