Active service system (ASSYST), function - GF00.20-P-0003P

Model 203 with ENGINE 271 as of 1.6.05, 272, 642 

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.

The service interval in the case of favorable evaluation (few cold starts, driving predominantly in the mean speed range) is longer than in the case of 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 together with the service symbol upon request of the driver or if a warning threshold has been undershot.

Engine oil monitoring 

In the event of oil starvation, the text fields in the multifunction display (A1p13) show a warning message for the oil level. The oil can symbol also appears. Depending on the assessment and the quantity rebate 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
• Coolant temperature

The instrument cluster (A1) receives this information over the Controller Area Network bus Class C (engine compartment) (CAN-C) from the CDI control unit (N3/9) or the ME-SFI [ME] control unit (N3/10).

The oil level is measured by the oil level check switch (S43).

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).

Mileage traveled 

For calculating the travel distance, the ASSYST receives the signals of the 4 wheel speed sensors from the ESP and BAS control unit (N47-5) via CAN-C.

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.

	Active Service System (ASSYST), block diagram		GF00.20-P-0003-03P
	Active service system (ASSYST) Operating instructions, resetting		GF00.20-P-0003-01P
	Active service system (ASSYST), Mercedes- Benz driver information service	Display indications	GF00.20-P-0003-02PA
		Remaining distance information	GF00.20-P-0003-02PE
		Remaining time indication	GF00.20-P-0003-02F
	Remaining distance, function		GF00.20-P-2007P
	Remaining time, function		GF00.20-P-2008P
	Engine oil monitoring, function		GF00.20-P-2009P
	Display service scope, function		GF00.20-P-2010A