Mercedes-Benz ML320. Manual — part 552

Fig. 313: Identifying 3-Pin MLK Plug

Fig. 314: Identifying 4-Pin MLK Plug

Fig. 315: Identifying 8-Pin MLK Coupling

2004 Mercedes-Benz ML350

1998-2005 GENINFO Overall vehicle - 163 Chassis

me

Fig. 316: Identifying 14-Pin MLK Plug

ACTIVE SERVICE SYSTEM (ASSYST) OPERATING NOTES - GF00.20-P-0003-01A

Displaying remaining distance, remaining time or service exceeded when vehicle stationary or when
driving on driver request:



Wake-up instrument cluster.



Start switch in position "2" or driving.



Operate reset button for trip counter twice within 1 s: the current remaining distance, the current
remaining time or the current service exceeded appears.

Displaying oil level at driver request:



After start switch in position "2", wait 10 s until "DISPLAY OIL LEVEL" text and oil can symbol (or oil
can and clock symbol) appears.



Press reset button for trip counter twice within 1 s: the message "OIL LEVEL OKAY" (or "O.K.") or the
current missing oil quantity appears. If correct oil level measurement is not possible, the text "OBSERVE
WAITING TIME" appears (or the clock symbol and the oil can symbol; the clock symbol flashes).

Notes on replacement of
safety-relevant and special
components

Model 124, 126, 129,
140, 163, 164, 168, 169,
170, 171, 199, 202, 203,
208, 209, 210, 211, 215,
216, 219, 220, 221, 230,
240, 245, 251, 414, 461
as of 1.4.94, 463

AH00.19-P-1000-08A

Notes regarding plug
connections

AH00.19-P-1000-06A

Remove contacts from
mini laminated contact
coupling

AR00.19-P-0120-26A

Remove contacts from
mini laminated contact
plug

AR00.19-P-0120-27A

2004 Mercedes-Benz ML350

1998-2005 GENINFO Overall vehicle - 163 Chassis

me

(The texts in parentheses relate to vehicles without multifunction display.)

Resetting ASSYST after oil change (oil change reset) at instrument cluster:



Move start switch into position "2".



Within the first 4 s after moving start switch into position "2": press reset button for trip counter twice
within one second. The display for the service request is thus activated for 10 s.



Within these 10 s move start switch into position "0". The service request continues to be displayed.



Press reset button for trip counter and hold pressed .



Move start switch into position "2".



Continue to hold reset button for trip counter pressed (about 10 s) until the signal sounds and the new
start distance appears in the display.

BLOCK DIAGRAM OF ACTIVE SERVICE SYSTEM (ASSYST) - GF00.20-P-0003-03A

Fig. 317: Block Diagram Of Active Service System (ASSYST)

ACTIVE SERVICE SYSTEM (ASSYST) DISPLAY FACILITIES - GF00.20-P-0003-04A

The table shows a number of possible types of displays of the active service system for different vehicles and
different instrument clusters.

(The display appears in the language set with the HHT under national code.)

2004 Mercedes-Benz ML350

1998-2005 GENINFO Overall vehicle - 163 Chassis

me

Fig. 318: Identifying Active Service System (ASSYST) Display

ACTIVE SERVICE SYSTEM (ASSYST) INFLUENCING PARAMETERS - GF00.20-P-0003-05A

The values of various influencing parameters are required by ASSYST for calculating the demand-based service
interval, and these are included in the calculation of the service interval as weighting factors . There are two
versions within ASSYST, the difference being in the oil level sensors fitted:



The familiar oil level indicator switch (S43) is fitted to engines (104, 111, 119, 120, 602.982, 604, 605,
606). In view of the fact that this is a switch, it is only possible to detect if the oil level drops below the
minimum level.



The oil sensor (oil level/temperature/quality, B40) is used on more recent engines (e.g. 112, 113, 166,
611, 668). This sensor consists of 2 capacitor systems with the engine oil as an insulator. If the water
content of the oil or the oil level changes, there is a change in the capacitance of the "capacitor".

The capacitance is thus a measure for the oil level.

In addition, the oil sensor (oil level/temperature/quality, B40) contains a temperature sensor which
detects the temperature of the engine oil.

All the signals are processed in the electronics integrated in the sensor to form a PWM (pulse width
modulated) signal, and passed to the engine control module (N3).

In addition to the weighting factors, which depend on reallife driving conditions, quality factors are also used
for calculating the demand-based service interval (remaining distance and remaining time).

Survey of ASSYST influencing parameters



Weighting factors (dependant on reallife driving conditions):



Load torque



Engine speed



Oil level



Engine oil temperature



Oil correction factor (is used as comparative value for determining oil level)



Coolant temperature

These data are supplied by the injection system control module (N3) to the service microprocessor over
the CAN.

The data relating to oil level, engine oil temperature and oil correction factor are supplied by the oil
sensor (oil level/temperature/quality, B40) through the injection system control module (N3), and are
therefore only available on engines fitted with this sensor.



Quality factors (these are factory-set to base values and can be changed with the HHT, if operating
conditions of the vehicle so necessitate; they influence the start distance):

2004 Mercedes-Benz ML350

1998-2005 GENINFO Overall vehicle - 163 Chassis

me