Component description for an ignition coil (Engine 273) - GF15.10-P-2100V

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ENGINE 273.923 in MODEL 164

ENGINE 273.943 in MODEL 164

ENGINE 273.963 in MODEL 164, 251

Shown on ENGINE 272

Fig 1: Identifying Ignition Coil Cylinder 1 To 6 - Shown On Engine 272

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Location

For each cylinder, a dedicated ignition coil is plugged directly onto the spark plugs.

Task

Supplying adequate ignition energy in all operating conditions for the particular ignition circuit.

Shown on engine 272

Fig 2: Identifying Ignition Coils - Shown On Engine 272

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Shown on engine 273

Fig 3: Identifying Ignition Coils - Shown On Engine 273

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Design

Shown on engine 272

Fig 4: Ignition Coil Design - Shown On Engine 272

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

The ignition output stages are integrated in the ignition coils.

Internal circuitry of ignition coils with integral output stage

Shown on engine 272

Fig 5: Circuit Diagram Of Ignition Coils With Integral Output Stage - Shown On Engine 272

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function

An output stage is located in each ignition coil for the primary circuit. The ME control unit actuated the ignition coil primary circuit between terminals 2 and 4. The current flow in the primary coil (L1) causes a magnetic field to form. The dwell angle control determines the operating time of the ignition coil primary circuit and thus the magnetic saturation of the ferrous core of the ignition coil.

The primary current flow is interrupted at the moment of ignition timing point. The sudden collapse of the magnetic field generates the ignition voltage in the secondary coil (L2) which is fed directly to the spark plugs.

The voltage supply of the ignition coils is protected at circuit 87 M1

A diode is integrated in each ignition coil for suppressing additional ignition sparks when the output stage is switched off.

Because of the diodes, it is not possible to measure the resistance in the secondary windings. For diagnosis of the ignition coils, the primary current is measured. The capacitive tap is used to connect measuring equipment.