12 13... Ignition coil faults

Evaluation of ignition voltage peaks and attenuation process at idling speed.

1. Beginning of attenuation processes with normal peaks upwards and downwards.
2. Beginning of attenuation processes strongly shortened Ignition coil is defective!
3. Absence of initial downwards attenuation.

Ignition coil is defective!

Fig 1: Evaluation Of Ignition Voltage

Courtesy of BENDIX HEAVY VEHICLE SYSTEMS GROUP.

Evaluation of sparking voltage line at idling speed.

1. Normal combustion period.
2. Normal attenuations to sparking voltage line.

Fig 2: View Of Normal Condition

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Ignition coil is OK.

1. Shorter sparking period.
2. Attenuation to sparking voltage line is only slight.

Fig 3: Evaluation Of Sparking Voltage - Shorter Period

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Ignition coil is defective!

1. Much shorter sparking period.
2. Attenuations to sparking voltage line absent.

Fig 4: Evaluation Of Sparking Voltage - Much Shorter Period

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Ignition coil is defective!

No sparking voltage line.

Fig 5: Evaluation Of Sparking Voltage - No Sparking

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Ignition coil is defective!

Evaluation of combustion voltage line at raised engine speeds approx. 1500 RPM for 1 min.

1. Normal combustion period.
2. Normal attenuations to sparking voltage line.

Fig 6: View Of Normal Combustion Period

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Ignition coil is OK.

1. Shorter sparking period.
2. Attenuation to sparking voltage line is only slight.

Fig 7: Evaluation Of Combustion Voltage - Shorter Sparking Period

Courtesy of BMW OF NORTH AMERICA, INC.

Ignition coil is defective!

1. Normal combustion period.
2. Attenuations to sparking voltage line absent.

Fig 8: Attenuations To Sparking Voltage Line Absent

Courtesy of BMW OF NORTH AMERICA, INC.

Ignition coil is defective!