1997 MERCEDES-BENZ ML500 spark plugs

Two spark plugs for each cylinder are beneficial because of the arrangement of the valves for achieving optimal
emission levels and smooth engine running.
Each spark plug is actuated separately by the ME-SFI control unit through its own ignition coil. On engine 112,
113 both ignition coils of a cylinder are combined to form a dual ignition coil.
In the lower part load range up to approx. 2000 rpm both ignition sparks of a cylinder are triggered
simultaneously. At moderate and high engine loads, the ignition sparks are triggered offset by as much as 10°
crank angle. In this case, the sequence of actuation is constantly varied in order to achieve a uniform wear of
both spark plugs and to avoid deposits on only one side of the combustion chamber.

For troubleshooting in the dual ignition system, it is possible to switch off one ignition circuit each with HHT or
STAR DIAGNOSIS.
ME-SFI ignition system function
diagramEngine 104GF15.12-P-0001-01D
Engine 111GF15.12-P-0001-01G
Engine 112GF15.12-P-0001-01A
Engine 113GF15.12-P-0001-01B
Engine 119GF15.12-P-0001-01E
Engine 120GF15.12-P-0001-01F
ME-SFI control unit
position/task/design/ function GF07.61-P-5000F
ECI ignition system functionEngine 137GF15.15-P-3000L
Ignition coils,
location/task/design/functionEngine 119, 120GF15.10-P-3102F
Engine 104, 111GF15.10-P-3102G
Engine 112, 113GF15.10-P-3102A
Crankshaft position sensor,
location/task/ design/function GF07.04-P-4116F
Camshaft Hall sensor,
location/task/design/ function GF07.04-P-4117F
Spark plugs,
location/task/design/function GF15.10-P-3101F
Intake air temperature sensor,
location/task/ design/function GF07.04-P-2100F
Hot film mass air flow sensor,
location/task/ design/functionEngine 119, 120 (round
connector)GF07.07-P-4118E
Engine 104, 111, 112,
113, 137GF07.07-P-4118G
Coolant temperature sensor,
location/task/ design/functionEngine 104, 111GF07.04-P-5026G
Engine 112, 113, 137GF07.04-P-5026A
Engine 119, 120GF07.04-P-5026F
Electronic accelerator, Engine 104, 111, 112, GF30.20-P-3010E

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:54 PMPage 19 © 2006 Mitchell Repair Information Company, LLC.

version FB6 with code ZS6, -
special protection version FB7
with code ZS7, additional battery
100 Ah incl. cutoff relay code E26.
Model 463.248 with: special
protection version, code 979, -
special protection version FB6,
code ZS6, -special protection
version FB7, code ZS7, -additional
battery 100 Ah including cutoff
relay, code E26.AR54.10-P-0003PM
3.1Unclip cover on front
side of engineModel 211, 215, 220, 230.475/476
4.1Remove engine cover
with integrated air filterExcept model 170.466,
203.065/076/265/276, 209.376/476
from 24.4.04, 211.076/276,
215.374, 220.074/174, 230.474,
463.270/271
The air filter is integrated in the
engine cover. Remove the engine
cover or the air filter housing by
pulling it from the cylinder head
covers vertically in the upward
direction.
4.2Remove air filter housingModel 170.466, 203.065/265,
211.076/276, 215.374,
220.074/174, 230.474AR09.10-P-1150SVK
Model 203.076 /276, 209.376 /476
from 24.4.04, 171.473AR09.10-P-1150AC
Model 463.270/271AR09.10-P-1150GX
5Unscrew screw (5/3) *BA15.10-P-1001-
04A
6Detach spark plug
connector (5/1) from the
spark plugs Pry off spark plug connector
(5/1) using open-end wrench,
double over the cylinder head
cover of the spark plugs.
Installation: Observe the
identification of the connector
(arrow) on the cylinder head cover
and the ignition coil of cylinders 1
to 6 or 1 to 8 for the corresponding
spark plug connector (5/1).
Double open-ended wrenchFig. 24
7Separate electrical
connector of ignition coil
of cylinder 1 to 6 (T1/1 Installation: Install new cable
ties.

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:54 PMPage 39 © 2006 Mitchell Repair Information Company, LLC.

Fig. 45: Identifying Harmonics - Positive Diode Defective
Fig. 46: Identifying Diode Harmonics OK

REPLACE SPARK PLUGS - AP15.10-P-1580GH
ENGINE 112.942 in MODEL 163.154
ENGINE 112.970 in MODEL 163.157
ENGINE 113.942 in MODEL 163.172
ENGINE 113.981 in MODEL 163.174
ENGINE 113.965 in MODEL 163.175

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:55 PMPage 71 © 2006 Mitchell Repair Information Company, LLC.

Fig. 47: Identifying Spark Plugs And Cylinder 4 Ignition Coil

Remove/install and
replacing

Risk of death due to
contact with high-voltage
conductive partsDo not touch parts which
conduct high voltages.
Persons who are carriers
of electronic implants
(e.g. cardiac pacemaker)
may not carry out any
work on the ignition
systemAS15.10-Z-0001-01A
Notes on avoiding damage
to ignition systemEngine 104, 111, 112,
113, 119, 120,271AH15.10-P-0002-01D
1Remove/install air filter
upper section
2
Remove ignition coils
Remove/install ignition
coils
AR15.12-P-2003A
3Disconnect spark plug
connectors Prise over cylinder
head cover.
Double open-ended
wrenchFig. 24
Checking
4Check spark plug Replace, if necessary.

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:55 PMPage 72 © 2006 Mitchell Repair Information Company, LLC.

Spark plugs
Fig. 48: Identifying Spark Plug Wrench (112 589 01 09 00)

Fig. 49: Identifying Open
-End Wrench, Double (110 589 01 01 00)
connectors, ignition coil
connectors and ignition
lines for damage,
deformation and crack
formation
5Remove/install spark plugs
(R4) *BA15.10-P-1001-01A
Spark plug wrenchFig. 48
NumberDesignationEngine
104,110,111,
113.940/941/942/943/
944/948/960/961/962/
963/964/965/966/967/
968/969/971/980/981/
982/984/986/992/993/
995,115,117,119,
120Engines
112.910/911/
912/913/914/
915/916/917/
920/921/922/
923/940/941/
942/943/944/
945/946/947/
949/951/953/
954/955/960/
961/970/972/
973/975/976
BA15.10-P-1001-
01ASpark plugsNm2828

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:55 PMPage 73 © 2006 Mitchell Repair Information Company, LLC.

Models 211.061/065/070AR54.10-P-0003T
Model 215, 220AR54.10-P-0003I
Model 230.474 /475AR54.10-P-0003R
All models 463 except
463.241/248 with code 979.AR54.10-P-0003G
Model 463.241 with code
979AR54.10-P-0003PV
Model 463.248 with code
979AR54.10-P-0003PM
Notes on batteryAll modelsAH54.10-P-0001-01A
2Remove spark plugsTo ensure that the engine
can be easily cranked when
drawing in the timing chain,
and to avoid the timing
chain jumping across.
Remove only once spark
plug of each cylinder.
Replace spark plugsModel 163AP15.10-P-1580GH
Models 220, 230.474/475AP15.10-P-1580AB
Models 210, 208, 202AP15.10-P-1580A
Models 203, 170, 209, 211
with engine 112
Models 209, 211 with
engine 113
3Remove cylinder head
coversAir filter mounted on
vehicleAR01.20-P-5014B
Air filter mounted on
engineAR01.20-P-5014BV
4.1Remove fan shroud Not models
211.061/065/070, 230.475
Models 220, 230.474
AR20.40-P-6800AB
4.2Remove electric fanModel 170AR20.40-P-5000SV
Models 203, 209AR20.40-P-5000PV
Model 163.174AR20.40-P-5000GH
5Position engine to 40°
after TDC of first
cylinder. Engine must not be
cranked backwards. The
notches of the camshafts
must be pointing in the
direction of the inner V.
It must be possible to easily
insert the two locking
plates.
If this is not possible: ?
Set the basic position of AR05.20-P-6020AU

2004 Mercedes-Benz ML350
1998-2005 ENGINE Engine timing - 163 Chassis
me
Saturday, October 02, 2010 3:39:37 PMPage 29 © 2006 Mitchell Repair Information Company, LLC.

Intake manifold
211.061/065/070, 230.475
Models 220, 230.474
22.2Install electric fanModel 170AR20.40-P-5000SV
Models 203, 209AR20.40-P-5000PV
Model 163.174AR20.40-P-5000GH
23Install cylinder head
coversAir filter locat ed at vehicle
side.AR01.20-P-5014B
Air filter locat ed on engine
side.AR01.20-P-5014BV
24Install spark plugs
Replace spark plugsModels 220, 230.474/475AP15.10-P-1580AB
Models 210, 208, 202AP15.10-P-1580A
Models 170, 203, 209, 211
with engine 112
Models 209, 211 with
engine 113
Model 163AP15.10-P-1580GH
25Connect ground cableModel 203AR54.10-P-0003P
Models 129, 163, 170, 202,
208, 210AR54.10-P-0003A
Model 209AR54.10-P-0003Q
Models 211.061/065/070AR61.20-P-1105T
Model 215, 220AR54.10-P-0003I
Model 230.474/475AR54.10-P-0003R
All models 463 except
463.241/248 with code 979AR54.10-P-0003G
Model 463.241 with code
979AR54.10-P-0003PV
Model 463.248 with code
979AR54.10-P-0003PM
Risk of accident caused
by vehicle starting off by
itself when engine is
running. Risk of injury
caused by contusions and
burns during starting
procedure or when
working near the running
engineSecure vehicle to prevent it
from moving by itself.
Wear closed and snug-
fitting work clothes.
Do not grasp hot or rotating
parts.AS00.00-Z-0005-01A
26Run engine and inspect
for leaks
NumberDesignationEngines 112, 113

2004 Mercedes-Benz ML350
1998-2005 ENGINE Engine timing - 163 Chassis
me
Saturday, October 02, 2010 3:39:37 PMPage 32 © 2006 Mitchell Repair Information Company, LLC.

2Remove spark plugs To ensure that the
engine can be easily
cranked when drawing in
the timing chain, and to
avoid the timing chain
jumping across.
Remove only one spark
plug at each cylinder.

Replace spark plugsModel 463.AP15.10-P-1580GA
Model 129.AP15.10-P-1580A
Models 202, 208, 210 with
engine 112.
Models 163.AP15.10-P-1580GH
3Remove cylinder head
coversAir filter locat ed at vehicle
side.AR01.20-P-5014B
Air filter located on
engine side.AR01.20-P-5014BV
4Remove viscous-drive fan. Right-hand thread!AR20.40-P-5660C
5Remove fan shroud On model 163 unscrew
bolts at bottom of fan
shroud.
Model 463.AR20.40-P-6800V
6Position engine at a 40°
crank angle before
ignition TDC of cylinder
1. Engine must not be
cranked back.
The notches of the
camshafts must be
pointing in the direction of
the inner V.
It must be possible to
easily insert the two
locking plates.
If this is not possible: ?
Set the basic position of
camshafts.AR05.20-P-6020AU
The copper tabs of the
timing chain must be
aligned with the markings
on the camshaft sprockets.
Because of the unevenly
long travel of the timing
chain it may be necessary
to crank the engine as
much as 14 times until the
copper tabs are aligned
with the markings on the

2004 Mercedes-Benz ML350
1998-2005 ENGINE Engine timing - 163 Chassis
me
Saturday, October 02, 2010 3:39:37 PMPage 36 © 2006 Mitchell Repair Information Company, LLC.