Active service system (ASSYST PLUS), function - GF00.20-P-0004FL

MODEL 212 

Function requirements, general 

• Terminal 15 ON

The electronic ignition lock control unit (N73) transmits the circuit status of circuit 15 via interior CAN (CAN B) to the instrument cluster (A1).

Active Service System PLUS (ASSYST PLUS), general 

The ASSYST PLUS calculates when the vehicle is due for a service. This is true either after a precisely defined kilometer mileage or after a certain time interval, depending on which limit is reached first. In addition, it allows the driver or the service personnel an overview of the expected service operations at the vehicle.

It is calculated in the ASSYST control unit, which is integrated in the instrument cluster as a software solution. The ASSYST control unit takes into account the time and distance-dependent additional operations in accordance with the vehicle equipment. The service scope and the time that the service is due are displayed via the multifunction display (A1p13) in the instrument cluster.

ASSYST PLUS comprises the following subfunctions:

• Function sequence for determining the remaining distance 
• Function sequence for determining the remaining time 
• Function sequence for evaluating data 
• Function sequence for service display 
• Function sequence for service interval reset 

Function sequence for determining the remaining distance 

When determining the remaining distance, the wheel speed determined by the left front axle RPM sensor (L6/1), right front axle RPM sensor (L6/2), left rear axle RPM sensor (L6/3) and right rear axle RPM sensor (L6/4) is read in by the Electronic Stability Program control unit (N30/4) (model 212 (except 212.074/077/092/095/098/274/277/292/298) without code (233) DISTRONIC PLUS) or by the regenerative braking system control unit (N30/6) (model 212.095/098/298) or by the Premium Electronic Stability Program control unit (N30/7) (model 212 (except 212.095/098/298) with code (233) DISTRONIC PLUS, model 212.074/077/092/274/277/292) and sent to the instrument cluster via chassis CAN (CAN E) up to 28.2.13 or via chassis CAN 1 (CAN E1), front SAM control unit with fuse and relay module (N10/1) and chassis CAN 2 (CAN E2) as of 1.3.13. The instrument cluster uses the received values to calculate the travel distance covered and processes this in the ASSYST control unit.

The remaining distance to the next service is determined by the countercheck with the travel distance reading that was reset and stored at the last service.

The remaining distance is the primary decisive factor for the service indicator if the remaining distance is reached before the remaining time.

The service interval based on remaining distance is permanently stored in the ASSYST control unit and is 25, 000 km for "Service A" or 50, 000 km for "Service B".

Function sequence for determining the remaining time 

The remaining time is determined in the ASSYST control unit. The remaining distance to the next service is determined by the comparison with the time of service reading reset and stored at the last service.

The remaining time is the primary decisive factor for the service indicator if the remaining time is reached before the remaining distance.

The service interval based on the remaining time is permanently stored in the ASSYST control unit and is 12 months for "Service A" and 24 months for "Service B".

Function sequence for evaluating data 

Apart from the evaluation factors which depend on the real driving conditions, quality factors for determining the service scope and intervals are taken into account by ASSYST PLUS. To do so, the ME-SFI [ME] control unit (N3/10) (with gasoline engine) or CDI control unit (N3/9) (with diesel engine) transmits the following variables via chassis CAN up to 28.2.13 or via chassis CAN 1 as of 1.3.13:

• Engine speed
• Engine oil pressure
• Engine oil level
• Engine torque
• Engine temperature
• Engine off time

Function sequence for service display 

The following notes with service code can be shown in the multifunction display:

• Service XX in XX days
• Service XX in XXXX km/miles
• Carry out service XX

If service is past due, the following messages are shown:

• Service XX has been due for XX days
• Service XX has been due for XXXX km/miles

The display of the service date is rounded to 100 km or 100 miles or 5 days. The two-digit service code provides information on the scope of the service operations to be carried out.

The service scope is shown as a service code (e.g. "A1")

The letter denotes the scope of the service and the figure behind it provides the workshop with information on additional operations. This enables the workshop to already provide the customer with the most precise specifications possible on the time expenditure and expense of the due service when the appointment is made.

Function sequence for service interval reset 

The service can be reset using the OK button (S110s6) in the left multifunction steering wheel button group (S110).

The request is read in by the steering wheel electronics (N135) and sent over the steering LIN (LIN E1) to the steering column tube module control unit (N80). The steering column tube module control unit forwards the request via chassis CAN up to 28.2.13 or via chassis CAN 1, front SAM control unit and chassis CAN 2 as of 1.3.13 to the instrument cluster.

The multifunction display shows the message "Next Service". If the OK button is pressed for longer than t = 3 s, the multifunction display shows "Maintenance interval reset". The service interval has been reset.

Should an exchange of the instrument cluster become necessary, the current service data must be entered manually. The following parameters are required for this:

• Current kilometer reading/mileage reading
• Current date
• Km reading/mileage reading during last oil change (from service booklet)
• Date of the last oil change (from service booklet)