Cylinder Identification Sensor: Description and Operation

Ignition Reference Sensor:

The ignition reference sensor is an inductive pickup attached to the #4 spark plug wire to identify whe crankshaft position with respect to the engine firing order. The sensor consists of a coil winding in a plastic housing which is placed around the appropriate spark plug wire. Ignition pulses in the spark plug wire induce a measurable voltage within the coil windings of the reference sensor. Working in conjunction with the knock sensors, the E.C.U. can determine which cylinder is experiencing a knock condition.