GF00.20-P-0003R Active Service System (ASSYST), Function

GF00.20-P-0003R Active Service System (ASSYST), Function
- MODEL 230 up to model year 08 /YoM 07

General information
The fact that a service is due is indicated to the driver by the "Active Service System" (ASSYST) . The service that is required is also determined and indicated.
The ASSYST system is a demand-based engine oil service system.This means that various factors are consequently taken into account for calculating the demand-based service intervals in addition to a time-and-distance-only criterion.
These are quality factors that are coded using the STAR Diagnosis tool and evaluation factors that take into account driving conditions and therefore actual wear and tear.
If the evaluation is favorable (small number of cold starts, driving mainly in the mid rpm range) the service interval is longer than for an unfavorable evaluation.

Display
The information is displayed using the left multifunction display (A1p13) and right multifunction display (A1p15) in the instrument cluster (A1).
The service interval is displayed after a driver request or if a lower warning threshold is exceeded, automatically as a remaining distance remaining time in the text box (3) of the or right multifunction display (A1p15). The service symbol also appears in the left multifunction display (A1p13) (Fig. 1).

Engine oil monitoring
In the event of oil starvation or overfilling, information about the oil level is displayed in the text box (3) of the right multifunction display (A1p15) (Fig. 2). The oil can symbol also appears on the left multifunction display (A1p13).
The system is also capable of detecting oil refilling.If oil is replenished, a bonus is issued which may extend the service interval. Depending on the assessment and the bonus, the service interval is 15,000 to 30,000 kilometers or 10,000 to 20,000 miles.

Technology and influencing factors
ASSYST needs the values of various influential parameters to determine the demand-based service interval. These are used to calculate the service interval.

In addition to the evaluation factors that depend on the actual driving conditions, quality factors are also used to determine the demand-based service interval (remaining distance and remaining time).

Influencing variables
- Assessment factors (depending on the actual driving conditions):
- Load torque
- Engine speed
- Oil level
- Engine oil temperature
- Oil correction factor (serves as a comparative value for determining the oil level)
- Coolant temperature

The instrument cluster (A1) receives this information via the engine compartment CAN from the injection systems control unit (N3).

In order to obtain the oil level, engine oil temperature and oil correction factor information, the ME-SFI [ME] control unit (N3/10) reads in the information from the oil sensor (oil level, temperature and quality B40) .

- Quality factors (these are preset to basic values in the factory and can be modified using Star Diagnosis if required by the usage conditions, and affect the starting distance):
- Engine variant factor (gasoline/diesel)
- Country of use factor (distance driven is coded in accordance with national version).

- Mileage:
In order to calculate the travel distance, the ASSYST reads in the signals from the four wheel speed sensors via the engine compartment CAN from the SBC control unit (A7/3n1) and the ESP, SPS [PML] and BAS control unit (N47-5).

- Time
The ASSYST receives the time information from a timer integrated in the instrument cluster (A1).

Example of service display







1 Service symbol
2 Text: "SERVICE A" "IN XXXX KM" or "IN XXXX miles"
A1p13 Left multifunction display
A1p15 Right multifunction display

More displays can be found in other documents, particularly the one entitled: "Active Service System (ASSYST) Driver information".

Example of engine oil display







1 Oil can symbol
2 Text: "ENGINE OIL" "ADD 1.5 L!" or "ADD 1.5 QT!"
A1p13 Left multifunction display
A1p15 Right multifunction display

More displays can be found in other documents, particularly the one entitled: "Active Service System (ASSYST) Driver information".

Diagnosis
ASSYST diagnosis is performed using Star Diagnosis. Diagnosis is started via the instrument cluster ( A1). The injection systems control unit (N3) must also be taken into consideration during diagnosis.

Accidental oil change reset triggering
If an oil change reset has been triggered on the instrument cluster (A1) or using the Star Diagnosis tool, but no oil change is carried out, this oil change reset must be canceled immediately. An appropriate menu is available in Star Diagnosis for this purpose.

Instrument cluster (A1) replacement
If the instrument cluster (A1) has to be replaced, the coding and data records must be transferred to the new instrument cluster. See menu guidance in Star Diagnosis.

Oil sensor (oil level, temperature and quality B40) replacement
In the event of a complaint following the replacement of the oil sensor (oil level, temperature and quality B40) the minimum oil level warning may need to be adjusted (calibrated). This must always be carried out if the message "CHECK ENGINE OIL LEVEL!" appears, but the oil level is still OK according to the oil dipstick. The adjustment is made using Star Diagnosis (menu-guided).