In Coil-on-Plug (COP) technology, since each cylinder has a coil, the PCM controls individual cylinder firings for more precise ignition timing, reduced emissions and better fuel economy.
Where are these Ignition Coil-on-Plugs located?
The Coil-on-Plug coil is usually mounted on the top of the cylinder head just above the spark plug. The coil is connected to the spark plug with a stainless steel spring connector and protective insulating boot.
Will a malfunctioning Coil-on-Plug illuminate the check engine light or affect vehicle operation?
Yes, a failing Coil-on-Plug can illuminate the MIL, and is likely to create an engine misfire condition.
What are the common causes of failure?
Typically the COP coils fail due to exposure to high heat moisture and oil as they are mounted on top of the engine. The coil windings can fail due to the large flow of amperage
How to determine if Coil-on-Plugs are malfunctioning.
The output of the Coil-on-Plug coil can be determined by inserting a spark tester into the coil boot and cranking the engine over. Occasionally the wiring to the coil or the PCM can fail therefore the primary circuit to the coil should be checked for proper voltage and computer control.
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