System Description
WARNING: This page is about a different car, the 2006 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.
ECM measure the angle of the crankshaft based on the pulse signal from the CKP sensor and CMP sensor for each cylinder. If it detects a large change in the angle speed of the crankshaft, it concludes occurrence of a misfire. When the number of misfire is counted by ECM beyond the DTC detecting condition, it determine the cylinder where the misfire occurred and output it as DTC.