Q: What is the function of the Crankshaft Position (CKP) sensor?
A: The Crankshaft Position (CKP) sensor works with a reluctor wheel on the crankshaft to determine the crankshaft position. The PCM monitors the voltage of the CKP sensor signal circuit, which is pulled up to 12 volts. As each tooth of the reluctor wheel passes the sensor, the signal circuit is pulled to ground, creating a square wave signal. The spacing between the reluctor wheel teeth allows the PCM to determine the crankshaft position and synchronize the ignition system, fuel injectors, and knock control. The CKP sensor is also used to detect misfires. The PCM can detect malfunctions in the CKP sensor system and will set specific DTCs to indicate a problem. When testing, it is important to check for incorrect harness routing, poor connections, and damaged harnesses. If the sensor signal is affected when the harness is moved at a component, the component may be faulty. During removal and installation, the wiring harness should be disconnected from the CKP sensor, the fastening bolt should be removed, and the sensor and O-ring seal should be taken out. The mating surfaces of the sensor and engine block should be cleaned before installing the sensor with a new O-ring seal and fastening bolt. Finally, the wiring harness should be reattached, ensuring correct cable routing.