With the ignition switch in the ON or START position, voltage is applied to the ignition coil. Each ignition coil consists of two coils. High tension leads go to each cylinder from the ignition coils. The ignition coils fire two spark plugs on every power stroke (the cylinder under compression and the cylinder on the exhaust stroke). The Engine Control Module (ECM) provides a switching circuit to ground for energizing the primary ignition coils. The ECM uses the crankshaft position sensor and camshaft position sensor signal to time the energizing of the coil. When a primary ignition coil is energized and de-energized, the secondary coil produces a high voltage spike to the attached spark plugs.
Checking output signals from ignition coils every 10 sec. under detecting condition, if the signals indicating open or short in the circuit are detected for more than 5 sec., ECM sets this DTC. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item
Detecting Condition
Possible Cause
DTC Strategy
Detects a short to ground, to battery or open circuit
Poor connection
Open or short in harness
Ignition Coil
ECM
Enable Conditions
NO DTC related to this item
Engine running state
11V = Battery voltage = 16V
The above conditions are met > 0.5 sec.
Threshold value
Open or short
Diagnosis Time
Continuous (More than 5 sec.failure for every 10 sec.test)
MIL On Condition
2 driving cycles
Resistance(?)
Primary Coil
Secondary Coil
0.62 ± 10% (20?)
7.0k ± 15% (20?)
Fig.1) Normal waveforms of secondary coil at idle.
Fig.2) Normal data of Injection time at idle.
Fig.3) Abnormal data of Injection time when ignition coil (cylinder 2) open.