How to Measure the Camshaft Position Sensor?
2 Answers
The camshaft position sensor is one of the most critical sensors in the engine electronic control system. Its function is to provide the vehicle's ECU with signals to confirm the piston position, thereby determining the engine's ignition timing and sequential fuel injection. The specific measurement methods are as follows: 1. The output signal tooth surface displays a low state, while the gap displays a high state. 2. The camshaft sensor operates based on the principle of the crankshaft sensor. 3. The camshaft sensor gear disc may also have fundamental differences. Using a dedicated masking template, emergency operation can be performed after the crankshaft sensor fails. 4. The resolution of the camshaft sensor signal is too inaccurate, making it impossible to replace the crankshaft sensor during normal operation.
I encountered similar issues when driving a used car before. Testing the camshaft position sensor isn't actually difficult. First, loosen the engine cover with a wrench, locate the sensor position (usually near the cylinder head), then use a multimeter to check its resistance and voltage. Specifically, first disconnect the connector, turn the ignition switch to ON without starting the engine, and measure whether the voltage between the positive and negative terminals is within the 5-12V range. Then measure the signal line voltage - it should normally show fluctuations. If there's no output signal, the sensor might be aged or contaminated, requiring cleaning or replacement. A faulty sensor can cause hard starting or sudden stalling, affecting driving safety, so I check these regularly. Don't underestimate how even dirt can damage the system. During routine maintenance, simply cleaning the sensor interface can prevent many problems.
