Ignition Coil: Description and Operation
IGNITION COILThe ignition coil assemblies for the 2.7L are mounted on the intake manifold. It is a coil on plug assembly and each cylinder has an ignition coil assembly.
The Auto Shutdown (ASD) relay provides battery voltage to the ignition coil. The PCM provides a ground contact (circuit) for energizing the coil. When the PCM breaks the contact, the magnetic energy in the coil transfers to the secondary causing the spark. The PCM will de-energize the ASD relay if it does not receive the crankshaft position sensor and camshaft position sensor inputs. Refer to Auto Shutdown (ASD) Relay-PCM Output, for relay operation.
IGNITION COIL CAPACITOR
There is a coil capacitor added to each bank of cylinders for radio noise suppression.