How to Test the Camshaft Position Sensor?
2 Answers
The camshaft position sensor can be inspected using the following methods: 1. When the camshaft position sensor malfunctions, you can first check if there is a fault in the coil resistance of the camshaft sensor. First, disconnect the ignition switch, simply unplug the sensor's connector from the socket, and then use a multimeter in resistance mode to check whether the resistance values at each port meet the standard values. If the measured resistance values do not match the standard values, the sensor component needs to be replaced. 2. When testing the NE terminal and G terminal, the standard value in cold state is 155-250, and in hot state is 190-200. When testing the G1 terminal and G terminal, the standard value in cold state is 125-200, and in hot state is 160-235. When testing the G2 terminal and G terminal, the standard value in cold state is 125-200, and in hot state is 160-235. 3. When the camshaft position sensor malfunctions, you can check the signal voltage of the camshaft sensor. First, set the multimeter to voltage mode, then place it on the sensor's terminal 1 and terminal 3. When the engine starts, the voltage should be within the range of 0.2V-1.2V. When the engine runs at high speed, the voltage should be within the range of 1.8V-2.5V. 4. When testing the synchronization signal circuit of the camshaft sensor, first disconnect the internal connector of the sensor, then switch the ignition switch to the "ON" position, and start checking the voltage between terminal A and terminal C of the sensor. The normal voltage should be 8V, but when the engine starts running, check the voltage between terminal B and terminal C of the sensor. The voltage should alternate between 5V and 0V.
After all these years of repairing cars, I have a set of methods for testing the camshaft position sensor. First, use a diagnostic tool to read the fault codes—common codes like P0340 may indicate a sensor issue. Next, unplug the sensor connector and measure the voltage with a multimeter. The normal signal line reading should fluctuate between 0-5 volts. If it doesn’t change or the voltage is too low, the sensor is likely faulty. Then, check the connector and wiring for looseness or corrosion—sometimes a simple cleaning of the connector is enough. If the multimeter doesn’t reveal any issues, you can also use an oscilloscope to check the waveform. A normal signal should be a square wave; too much noise indicates sensor aging. Don’t forget to check the engine starting condition—a faulty sensor may cause the car to fail to start or idle unevenly. Always prioritize safety during testing—turn off the engine before proceeding. Regular maintenance can prevent such issues, like inspecting the sensor every two years to avoid breakdowns on the road.
