Mercedes-Benz ML320. Service manual - part 382

Fig. 1: Identifying Connection Cables Of Double Ignition Coil 

 Diagnosis with engine tester: 

Connect green connector (terminal 1) of engine tester alternatively to the yellow socket or green socket for 
assessing an ignition circuit with the primary adapter cable. 

Connect yellow connector (terminal 15) of engine tester to positive (tml. 30 /tml. 15). 

GENERAL NOTES ON TESTING CONTACTLESS HIGH VOLTAGE DISTRIBUTION - AH15.10-P-1003-01W 

  

If a complaint exists in the start or warming-up phase, do not condition engine to operating temperature but 
proceed on a complaint-related basis. 

Connections: set diagnostic tester to cylinder number 1 primary or secondary (if possible) and test through the 
ignition circuits one after the other. 

Diagnosis test oscilloscope / good image contactless high voltage distribution Secondary side (single 
image) Engine idling  

(shown on engine M119.981, cylinder 1 with Bosch ignition coil) 

Measuring range: 40 kV 

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me 

 

Time range: 5 ms 

Fig. 2: Diagnosis Test Oscilloscope / Good Image Contactless High Voltage Distribution Secondary Side 
(Single Image) Engine Idling 

Diagnosis test oscilloscope / good image contactless high voltage distribution Primary side (single image) 
Engine idling  

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me 

 

Fig. 3: Diagnosis Test Oscilloscope / Good Image Contactless High Voltage Distribution Primary Side 
(Single Image) Engine Idling 

BASIC KNOWLEDGE 

SPARK PLUGS, LOCATION/TASK/DESIGN/FUNCTION - GF15.10-P-3101F 

ENGINE 104, 111, 112, 113/, 119, 120, 137, 166 (except, 112.96, 113.98/99)  

Fig. 4: Identifying Spark Plug 

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me 

 

IGNITION COILS, LOCATION - GF15.10-P-3102-01A 

Fig. 5: Identifying Cylinder 1 To 6 Ignition Coil - Location On Engine 112

 

Spark plugs, location

One or two spark plugs are 
located in the cylinder head 
per cylinder.

 

 

Spark plugs, task

The spark plugs ignite the 
suctioned and compressed 
fuel-air mixture due to arcing 
between the electrodes.

 

 

Spark plugs, design

In the manufacturer's specific 
type symbols, all the spark 
plug features are assigned (e. 
g. heat rating, shape of 
seating, thread, width across 
flats, electrode material, 
spark position).

 

 

Spark plugs, function

The ignition voltage travels to 
the spark plugs from directly 
connected ignition coils or 
over the ignition lines from 
the ignition coils causing 
arcing in the air gap between 
the center and ground 
electrodes.

 

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me