How to Determine if the Crankshaft Position Sensor is Faulty?
2 Answers
Methods to determine if the crankshaft position sensor is faulty: 1. After the crankshaft position sensor is damaged, the engine may experience issues such as failure to start, no fuel injection, no ignition, or automatic stalling; 2. After the crankshaft position sensor is damaged, some car engines may not start, while others can still start, mainly due to differences in the control strategies of the engine ECU. The function of the crankshaft position sensor is to determine the position of the crankshaft, i.e., the angle of the crankshaft and the engine speed, and it usually works in conjunction with the camshaft position sensor. Through the crankshaft position sensor, it is possible to know which cylinder piston is at top dead center, and through the camshaft position sensor, it is possible to know which cylinder piston is in the compression stroke.
I had a similar issue before with my own car when the crankshaft position sensor failed. At that time, the car was extremely difficult to start, idled roughly like it had asthma, and occasionally stalled on the road. The most straightforward method I used was plugging in an OBD diagnostic scanner to directly read the fault codes from the engine control module. If codes like P0335 appeared, it pretty much confirmed the sensor was faulty. Additionally, I inspected the sensor's exterior for carbon buildup or looseness. Loose or corroded wiring connectors are also common culprits. I also listened to the engine sound—if the sensor signal was abnormal, the spark plugs might misfire, causing unusual noises. For safety, I recommend addressing it promptly. A professional shop can use an oscilloscope to test the signal waveform for a definitive diagnosis. Regularly cleaning dust around the sensor can extend its lifespan. Checking the engine warning light before driving is a simple yet practical habit.
