Crankshaft Position Sensor: Description and Operation

Camshaft Position (CMP) A and B (Top Dead Center (TDC) 1 and 2), and Crankshaft Position (CKP) Sensors
The CMP A (TDC 1) and CMP B (TDC 2) sensors detect the position of the No. 1 cylinder as a reference for sequential fuel injection to each cylinder. The CKP sensor detects engine speed and is used as one input to determine ignition timing and timing for fuel injection of each cylinder.