1997 MERCEDES-BENZ ML320 engine

SI18.00-P-0010A
Service Information: oil sludge
26.3.01

ENGINE
111 in MODELS 124, 163, 170, 202, 203, 208, 210

ENGINE
112 in MODELS 129, 163, 170, 202, 203, 208, 210, 220

ENGINE
112, 113 in MODEL 463

ENGINE
113 in MODELS 129, 163, 202, 208, 210, 215, 220

ENGINE
137 in MODEL 215, 220

ENGINE
166 in MODEL 168

Oil sludging in gasoline engines with ASSYST maintenance

system

Recently we have determined that time and time again oil

sludging occurs in gasoline engines with an ASSYST maintenance

system.

Oil sludging can lead to the following complaints:
D
engine oil consumption

D
engine smoke (white/blue)

D
influencing of oil level indicator

D
clogged oil filter, engine oil thickened like jelly

D
Check engine lamp illuminated

D
oil sludge visible during assembly job, e.g. in oil filter, in cylinder

head covers, condensation sludging
(engine 166) etc.

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The following list of causes may lead individually or as a combination
to engine oil sludging:

D
Crankcase ventilation inoperable, function orifices, bores,

passages in cylinder head cover, cylinder head, crankcase etc.

are mechanically sealed. A nonfunctioning crankcase

ventilation boosts loads on the engine oil through organic

nitrates. The risk of oil sludging increases.

The mechanical condition of the engine is always to be

checked, i.e. all engine oil drain orifices on the cylinder head

and crankcase and all crankcase ventilation ducts must be free

of obstacles. Crankcase breather lines may not be kinked.
Check the ventilation bores in the cylinder head covers.

-----------------------------------------------------------------------------------------

D
The engine oil used does not comply with the specifications in

Sheet 229.1 or 229.3 of the Specifications for Service Products.

The additive process, e.g. dirt-carrying capability, neutralization

capability and oxidation resistance as well as the quality of the

base stock influence sludging time.

Use of engine oils with best possible resistance to formation of

sludge, i.e. use only tested and approved engine oils (from

Sheet 229.1 or 229.3). The best protection is afforded by the

engine oils on Sheet 229.3, which fulfill more stringent

specifications with regard to preventing sludge and deposits
(see Sheet 221.0, page 11). These oils have a distinctly better

anti-sludge characteristic than other engine oils.

D
Sludging after adding a fuel or engine oil special additive.

Do not use fuel or engine oil special additives. More information

hereto is available on Sheet 219.0 of the Specifications for

Service products. Reference to customer not to use special

additives.

D
Engine oil change not performed according to ASSYST

specifications. At driven distances

exceeding > approx. 3000 km, engine oil sludging may occur.

-----------------------------------------------------------------------------------------
Comply with engine oil and filter change as under ASSYST

specifications. Observe remaining distance.

D
Fuel grade lies outside standard (regionally contingent). If

contaminated, deficient fuel is used, then engine oil sludging

may occur even where approved engine oil is used.

Operation with fuel, e.g. as under DIN EN 228. Clarify refueling

behavior of customer. If engine operation regional, is

temporarily possible with deficient oil only, then the startup

distance has to be individually reduced, i.e. the oil change

temporarily performed at an interval of, e.g. 10,000 km.

D
Radiator antifreeze penetration into engine oil, e.g. through an

internal engine leak (cylinder head gasket, casting porosity).

The engine oil sludges within a short period. The crankcase

ventilation clogs up and stops functioning. Condensation

sludging clogs up the oil separator cells

(engine 166).
Rectify coolant leakage. Clean all sludged engine parts, in

particular the crankcase ventilation parts. If the occurrence

repeats, and casting porosity is suspected, e.g. replace

crankcase.

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Copyright DaimlerChrysler AG 20.05.2006 CD-Ausgabe G/10/04 . This WIS print-out will not be recorde
d by Modification services.
Page 1

Measures for slightly sludged engine:

Oil and filter change. Purge engine, i.e. normal engine operation

in neutral, or while driving, using oil from Sheet 229.3, 228.3, or

228.5. Drain off scavenging oil after purging process (approx. 1

hour). Repeat purging process if necessary. Refill using engine oil

from Sheet 229.3, or 229.1. The first oil change after clearing the

sludge should be performed after approx. 10,000 km or beforehand;

when doing so use engine oil from Sheet 229.3.

Measures for severely sludged engine:

Engines with severe oil sludging and caking onto engine parts

and into bores have to be dismantled and mechanically cleaned.

Tough sludge residue must not enter the clean side of the oil circuit,

as otherwise, e.g. the piston oil spray and the hydraulic

compensation elements may have their functionality impaired. Refill

using engine oil from Sheet 229.3, or 229.1.

The first oil change after sludging should be performed after approx.

10,000 km; when doing so use engine oil from

Sheet 229.3.
Warranty/goodwill regulations

If in combination with engine oil sludging a warranty/goodwill claim is

submitted, then a regular documentation of maintenance must be

presented. The ASSYST printout is to be filed carefully for further

reference.

Oil sludging in combination with an exceeded oil change interval, or

because of special additives in the fuel/engine oil are costs to be

borne by the customer.

Copyright DaimlerChrysler AG 20.05.2006 CD-Ausgabe G/10/04 . This WIS print-out will not be recorde
d by Modification services.
Page 2

1998-2005 ACCESSORIES & BODY CAB
Throttle Control, Speed Control Systems - 163 Chassis
BASIC KNOWLEDGE
ELECTRONIC ACCELERATOR, LOCATION/DESIGN/FUNCTION - GF30.20-P-3010E
ENGINE 104.941 /943 /944 /991 /994 as of 1/8/96
ENGINE 104.995
with CODE (494a) USA version
with CODE (807) Model year 1997
with CODE (808) Model year 1998
with CODE (498) as of Model year 97 Japanese version
ENGINE 111.943 /947 /951 /952 /955 /956 /957 /958 /973 /982 /983,
111.944/975 as of 1.8.96,
111.946 as of 1.6.98,
111.921/942 as of 1.9.98
ENGINE 111.945
in MODEL 208.335 /435 as of 1.6.98,
202.020/080 as of 1.9.98
ENGINE 111.974
with CODE (494a) USA version
with CODE (807) Model year 1997
with CODE (808) Model year 1998
ENGINE
112.910 /911 /912 /913 /914 /916 /917 /920 /921 /922 /923 /940 /941 /942 /943 /944 /946 /947 /949 /953 /954 /9
5
ENGINE 113.940 /941 /942 /943 /948 /960 /961 /963 /965 /966 /967 /968 /969

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY CAB Throttle Control, Speed Control Systems - 163 Chassis

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY CAB Throttle Control, Speed Control Systems - 163 Chassis
me
Saturday, October 02, 2010 3:36:27 PMPage 1 © 2006 Mitchell Repair Information Company, LLC.
me
Saturday, October 02, 2010 3:36:30 PMPage 1 © 2006 Mitchell Repair Information Company, LLC.

ENGINE 119.980 /981 /982 /985
ENGINE 137.970
Fig. 1: Identifying Electronic Accelerator Function

The function of the electronic accelerator pedal EFP in the ME control unit determines the opening angle of the
throttle valve over the actuator EFP/TPM/LLR (other designation: throttle valve actuator).
Further functions are:
Idle speed control [ISC]
Cruise control mode
Variable speed limiter
30 km/hour limit
Reduce/increase the engine torque for ASR/ESP operation
short performance limitation, for example for a higher coolant temperature
Emergency electronic accelerator pedal
Safety concept
Actuate indicator lamp EPC (up to 5/96)
Storing faults
Data exchanger via CAN

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY CAB Throttle Control, Speed Control Systems - 163 Chassis
me
Saturday, October 02, 2010 3:36:27 PMPage 2 © 2006 Mitchell Repair Information Company, LLC.

The opening angle of the throttle valve will only be determined by the accelerator pedal specification when no
limiting functions are active.
The accelerator pedal position is detected by the set value potentiometer (B37r1) or Hall sensor in the pedal
value sensor (B37) and information is released to the ME control unit (N3/10). In this way, the ME-SFI control
unit determines the position of the throttle valve and actuates the throttle valve motor (M16/1 m1).
The actual value potentiometer in the actuator (M16/1r1) signals the throttle valve position back to the ME-SFI
control unit.
The second potentiometer in the actuator (M16/1 r2) and the second signal from the pedal value sensor
(potentiometer or Hall sensor) supplies a reference value for the plausibility check. In addition, the system
switches over to the second potentiometer or the Hall sensor if the first potentiometer or Hall sensor fails
(emergency mode).
Adaptive accelerator pedal (model 203, 209, 211, 215, 220, 230):
The engine control unit recognizes how the accelerator pedal is being actuated and switches between
characteristic curves. Eighty percent of the engine load is released for a pedal travel of about 50 % for a sporty
driver and about 40 % for a quiet driver. There is no further difference felt above a pedal travel of about 90 %.

If, for example, the characteristic curve for a quiet driver is active after a long drive on the motorway then the
accelerator pedal must be pressed down unusually hard to obtain a higher acceleration level.
Kickdown switch (S16/6)
The kickdown switch was no longer used from 9/01. Recognition of full load is now achieved over the signal
from the pedal value sensor. The pressure point on the accelerator pedal before achieving the full load position
remains.
Motor electronics control unit, location/task/
design/functionexcept M111 EVOGF07.61-P-
5000F
M111 EVOGF07.61-P-
5000GS
Electronic accelerator/cruise control/idle speed
control actuator location/task/design/functionexcept M111 EVOGF30.22-P-
4010F
Throttle valve actuator, location/task/design/
functionM111 EVOGF30.22-P-
4101GS
Pedal value sensor, location/task/design/
function GF30.20-P-
4011L
ME-SFI idle speed control function
Except engine 120 and engine 111 EVOGF30.22-P-
0003E
M111 EVOGF30.22-P-
0003GS

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY CAB Throttle Control, Speed Control Systems - 163 Chassis
me
Saturday, October 02, 2010 3:36:27 PMPage 3 © 2006 Mitchell Repair Information Company, LLC.

PEDAL VALUE SENSOR PO SITION - GF30.20-P-4011-01GH
Electronic power control indicator lamp,
location/task/design/functionEngine 119, 120 in Model 129, 140 up to
5/96GF30.20-P-
4012L
Electronic accelerator pe dal emergency running
mode functionEngine 104, 111, 112, 113, 119, 137GF30.20-P-
4026E
30 km/h limit, function
Model 129, 140 with Engine 104,
119.98, 120.98
except GF30.20-P-
4027F
Cruise control (CC) function
With cruise controlGF30.30-P-
0001F
Engine 104 (except HFM sequential
multiport fuel injection/ignition system),
119.98, 120.98

With cruise control
Engine 111, 112, 113, 137GF30.30-P-
0001FA
Variable speed limiter, functionAdditional cruise control function except
GF30.30-P-
3001A
Distronic (DTR), function
Model 220, 215 with code 219a up to
6/00GF30.30-P-
0002K
Model 203, 209, 211, 230 with code
219a
GF30.30-P-
0002KA
Model 215, 220 with code 219a as of
7/00
Pedal value sensor characteristic curve when
reversing function GF30.20-P-
4013E
ASR V control unit location/task/design/function
with code 471 a
Model 129, 140, 202 as of 6/94, 170,
208, 210GF42.40-P-
4500A
ESP control unit location/task/function
with code 472a
Model 129 with Engine 104, 119, 120
Model 140
Model 210 with engine 119
GF42.45-P-
4500A
with code 472a
Model 129 with engine 112, 113
Model 163 up to 8/02, 168, 215
Model 220 (except 220.08/18) Model
202, 208 with engine 112, 113
Model 210 with engine 111, 112, 113
GF42.45-P-
4500B
with code 472a
Model 170 with Engine 111, 112
Model 202, 208 with Engine 111
Model 203
GF42.45-P-
4500C
Model 211, 230GF42.45-P-
4500SL

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY CAB Throttle Control, Speed Control Systems - 163 Chassis
me
Saturday, October 02, 2010 3:36:27 PMPage 4 © 2006 Mitchell Repair Information Company, LLC.

Fig. 4: Identifying Internal Circuitry Of Pedal Value Sensor
The pedal value sensor based on the Hall principle consists of two Hall elements, 2 magnets, electronics and a
restoring spring. The magnets are moved by means of the linkage or cable attached to the pedal value sensor
and thus alter the direction of the magnetic field relative to the fixed Hall elements. This produces a change in
the voltage.
The pedal value sensor is supplied with 5V only at pin 1. Pin 2 is not connected internally. The information
regarding the accelerator pedal position is passed to the engine control module by means of two voltages (pin 4:
approx. 0 to 2.25V and pin 5: approx. 0 to 4.5V). The pedal value sensor with potentiometer can be replaced
with the pedal value sensor based on the Hall principle (but not vice versa).
PEDAL VALUE SENSOR DESIGN - GF30.20-P-4011-02C
Fig. 5: Identifying Accelerator Pedal Module With Kickdown Switch (Up To 7/02) Components
Illustration shows accelerator pedal module with kickdown switch (S16/6).
Was onl
y installed until about 7/02. One then used the accelerator pedal module with kick-down simulator (a).

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY CAB Throttle Control, Speed Control Systems - 163 Chassis
me
Saturday, October 02, 2010 3:36:27 PMPage 6 © 2006 Mitchell Repair Information Company, LLC.

Fig. 7: Identifying Internal Circuitry Of Pedal Value Sensor (Hall Principle)
The sensor on the accelerator pedal which works according to the Hall principle is integrated into the pedal
lever axis. It consists of a shaft with ring magnet. This rotates in a printed circuit board with stator in the fixed
Hall elements. This produces a change in the voltage.
The accelerator pedal sensor is supplied by the engine control unit with 5 V. The information regarding the
accelerator pedal position is passed on to the engine control unit by means of two voltages (pin 4: approx. 0 to
2.25 V and pin 5: approx. 0 to 4.5V).
The kick-down switch (S16/6) was no longer used from 7/02. Full load recognition takes place now over the
signal from the accelerator pedal sensor. The pressure point on the accelerator pedal is simulated before
achieving the full load position.
PEDAL VALUE SENSOR, LOCATION/TASK/DESIGN/FUNCTION - GF30.20-P-4011L
ENGINE 104.941 /943 /944 /991 /994 as of 1.8.96
ENGINE 104.995
with CODE (494a) USA-Ausfuhrung
with CODE (807) Model year 1997
with CODE (808) Model year 1998
with CODE (498) as of Model Year 97 Japan-Ausfuhrung
ENGINE 111.921 /942 as of 1.9.98,
111.946 as of 1.6.98,
111.944/975 as of 1.8.96,
111.943 /947 /951 /952 /955 /956 /957 /958 /973 /974 /982 /983

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY CAB Throttle Control, Speed Control Systems - 163 Chassis
me
Saturday, October 02, 2010 3:36:27 PMPage 8 © 2006 Mitchell Repair Information Company, LLC.