How to measure a three-wire crankshaft position sensor?
2 Answers
Measurement method for a three-wire crankshaft position sensor: 1. Turn off the ignition switch, disconnect the crankshaft position sensor connector, and measure the value range between terminal 1 and 2 of the sensor; 2. Turn on the ignition switch and measure the ground voltage of the two signal lines; 3. When starting the starter, measure the signal of the crankshaft position sensor. A sensor is a detection device that can sense the measured information and convert the sensed information into electrical signals or other required forms of information output according to certain rules to meet the requirements of information transmission, processing, storage, display, recording, and control. The characteristics of sensors include miniaturization, digitization, intelligence, multifunctionality, systematization, and networking. They are usually divided into ten categories based on their basic sensing functions: thermal elements, photosensitive elements, gas-sensitive elements, force-sensitive elements, magnetic-sensitive elements, humidity-sensitive elements, sound-sensitive elements, radiation-sensitive elements, color-sensitive elements, and taste-sensitive elements.
I encountered this issue last time when repairing my old Accord. The three wires of the crankshaft position sensor are actually quite easy to test: connect the black probe to ground and the red probe to the power wire—there should be 12V when the key is turned to the ON position. Then check the ground wire to ensure it's connected to the car body. The key is the signal wire—it's best to have an oscilloscope to check if the waveform is a clean square wave when starting the engine. If you don't have the equipment, you can also use a multimeter set to AC voltage—the needle should noticeably swing during startup. Be aware that oxidized connector pins can produce false signals. Last time, my car had acceleration hesitation due to oil contamination in the connector, and it was fixed after spraying electronic cleaner.
