LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> BMW >> 2002 >> 325Ci 2D Convertible, Automatic >> Repair and Diagnosis >> Engine Performance >> Ignition System >> Engine Electrical System - Repair >> Ignition coil >> 12 13... Ignition coil faults
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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
G00313217Courtesy of BENDIX HEAVY VEHICLE SYSTEMS GROUP.
NOTE: Higher ignition voltage peak is not always available.

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
G00313214Courtesy of BMW OF NORTH AMERICA, INC.

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
G00313219Courtesy of BMW OF NORTH AMERICA, INC.

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
G00313220Courtesy of BMW OF NORTH AMERICA, INC.

Ignition coil is defective!

No sparking voltage line.

Fig 5: Evaluation Of Sparking Voltage - No Sparking
G00313221Courtesy of BMW OF NORTH AMERICA, INC.

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
G00313222Courtesy of BMW OF NORTH AMERICA, INC.

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
G00313223Courtesy 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
G00313224Courtesy of BMW OF NORTH AMERICA, INC.

Ignition coil is defective!

scientia non olet · About LEMON Manuals