Rodeo S 2WD L4-2.2L (1999)
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The camshaft position (CMP) sensor sends a signal related to the position of the camshaft.
Based on these sensor signals, as well as engine load and engine coolant temperature information, the PCM controls the switching function of the ICM
by sending it a 5V signal. As long as the ICM receives the signal, it allows battery voltage to the ignition coil. That voltage allows a magnetic field to
build in the coil.
When the PCM requires a spark plug to fire, it shuts off the 5V signal to the ICM grounding it internally. This triggers the ICM to switch off the battery
voltage to the ignition coil, which causes the field to collapse. The lines of magnetic force pass through the secondary portion of the coil as they collapse.
As they intersect the coil, they induce high voltage in the secondary ignition circuit which travels toward ground through the spark plug.
