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

GF00.20-P-0003D Active Service System (ASSYST), Function
- Model 208 as of 1.8.99 with ENGINES 112, 113
- Model 210 as of 1.7.99 with ENGINES 112, 113, 611, 612, 613
- Model 203 with ENGINE 111, 112, 113, 271 up to 31.5.05, 611, 612, 646

15.03.07 The document has been updated to this date and will no longer be subject to revision.

General information
With the Active Service System (ASSYST) the driver's attention is drawn to a service due and the required service scope (A/B). The ASSYST system is a demand-based engine oil service system. In addition to the time and distance criterion, various factors are consequently taken into account for calculating the demand-based service intervals.
These are, on the one hand, quality factors which are coded via STAR DIAGNOSIS and, on the other hand, evaluation factors which take into account driving conditions and thus 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 displays are shown in the multifunction display (A1p13) of the instrument cluster (A1). The service interval is shown automatically as remaining distance or remaining time in the text fields together with the service symbol upon request of the driver or if a warning threshold is undershot.

Engine oil monitoring
If there is a shortage or an overfilling of oil, information regarding the oil level appears in the text fields of the multifunction display (A1p13). The oil can symbol also appears. In addition, it is possible to detect oil replenishments. If oil is replenished, a bonus is issued which may extend the service interval. Depending on the assessment the service interval for gasoline engines is 15,000 to 30,000 km or 10,000 to 20,000 miles, for diesel engines it is 20,000 to 40,000 km.

Technology and influencing factors
In order to determine the demand-based service interval, ASSYST requires the data relating to various influencing variables, which are used for calculating the service interval and the type of service (A or B) required.
In addition to the evaluation factors which depend on real driving conditions, quality factors are also used for determining the demand based service interval (remaining distance and remaining time).

Influencing variables and evaluation factors
dependent on real-life 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 over the Controller Area Network bus Class C (engine compartment) (CAN-C) from the vehicle-specific engine control unit.
The vehicle-specific engine control unit reads in the data for oil level, engine oil temperature and oil correction factor from the oil sensor (oil level, temperature and quality) (B40).

Quality factors
They are factory-set to base values. They can be changed via STAR DIAGNOSIS, if required by the operating conditions. They influence the starting distance:
- Engine version factor (gasoline/diesel)
- Country of use factor (the mileage is coded in accordance with the national version).

Time
The time information is supplied to the ASSYST by a time sensor integrated in the instrument cluster (A1).

Travel distance
To calculate the travel distance, ASSYST receives the signals of the 4 sensors for wheel speeds over CAN-C from the ESP and BAS control unit (N47-5) (models 203, 208) or ESP, SPS [PML] and BAS control unit (N47-5) (model 210).

Diagnosis of ASSYST is performed using STAR DIAGNOSIS. Diagnosis is started through the instrument cluster (A1). The engine control units are also included in the diagnosis.

If an oil change reset is initiated on the instrument cluster (A1) or using the STAR DIAGNOSIS, but an oil change not actually performed, then this oil change reset must be immediately reset. A corresponding menu is available in STAR DIAGNOSIS for this purpose.

If the instrument cluster (A1) has to be replaced, the codes and data records must be transferred into the new instrument cluster (A1). See menu guidance in STAR DIAGNOSIS.

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 possibly have 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 menu-assisted diagnosis is performed using STAR DIAGNOSIS.