What is the testing method for the camshaft position sensor?
3 Answers
The testing methods for the camshaft position sensor mainly include the following two approaches: The first method: Detection of the sensor's power supply voltage. Turn off the ignition switch, unplug the sensor wire connector, and use a multimeter's positive and negative probes to connect to terminals 1 and 3, respectively. When the ignition switch is turned on, the voltage should be above 4.5V. If the voltage is zero, it indicates a break or short circuit in the wiring harness, or an ECU fault. After turning off the ignition switch, continue to check for any breaks or short circuits in the wiring. The second method: Detection of the wire resistance. Use a multimeter to measure the resistance between terminal 1 of the sensor and terminal 62 of the ECU, terminal 2 of the sensor and terminal 76 of the ECU, and terminal 3 of the sensor and terminal 67 of the ECU. The resistance between each wire should not exceed 1.5 ohms. If the resistance is too high or infinite, it indicates poor contact or a break in the wiring harness, and the harness should be repaired or replaced. Fault diagnosis and troubleshooting methods for the camshaft position sensor: 1. Check the high-voltage spark. Pull out each cylinder's high-voltage wire and test-fire against the cylinder block to check the strength of the high-voltage spark. The high-voltage spark for each cylinder should be normal. 2. Check the spark plugs. The normal gap for spark plugs is generally 0.8mm, while high-energy electronic ignition systems may have larger gaps, up to 1.2mm. After inspection, the gaps of all spark plugs should be normal. 3. Check the air filter. Clean the air filter's mesh and inspect it for any damage.
I've worked in a repair shop for over a decade. When testing the camshaft position sensor, the most reliable method is to first unplug the connector and use a multimeter to check if the voltage at the interface is normal—usually around 5 volts. If there's no reading, it might be a power supply issue. Next, inspect the sensor itself for cracks or oil contamination; if the gap is too large, the signal will fluctuate. Then listen to the engine's starting sound—if it's rough or uneven, there's an 80% chance the sensor is faulty. I prefer using a diagnostic tool to read fault codes—it saves time and effort. With older cars, you might even need to replace the entire wiring harness. Proper maintenance can help you avoid these troubles. I recommend popping the hood for a quick visual inspection every month to catch issues early and prevent breakdowns on the road.
I enjoy tinkering with my car in my spare time, and testing the camshaft sensor doesn't require a trip to the repair shop. First, turn off the engine and locate the sensor, usually positioned at the top of the engine. Gently wiggle the connector to check for looseness—an easily overlooked detail. Set your multimeter to the voltage range, connect the leads, and take a reading. A normal reading should be around 5 volts; if it's too low, it indicates internal burnout. I also keep a used scanner handy—just plug it into the OBD port to monitor the data stream. Strong signal fluctuations mean it's working fine. This task isn't overly complicated, but don't get careless. Damaging parts isn't worth the hassle. Tools are cheap to buy online, saving money while learning new skills.
