Maintenance Required Lamp/Indicator: Diagrams

GF00.20-P-0003-03PP Active Service System (ASSYST), Block Diagram
- MODEL 203 with ENGINE 111, 112, 113, 271 up to 31.5.05, 611, 612, 646 up to Model Year 08 /AEJ 07
- MODEL 209.3 with ENGINE 112, 113, 271 up to 31.5.05, 612, 646
- MODEL 209.4 with ENGINE 112, 113

Shown with engine 646







a Timer
b ASSYST computer
A1 Instrument cluster
A1p13 Multifunction display
B11/4 Coolant temperature sensor
B40 Oil sensor (oil level, temperature and quality)
L5 Crankshaft position sensor
L6/1 Left front rpm sensor
L6/2 Right front rpm sensor
L6/3 Left rear rpm sensor
L6/4 Right rear rpm sensor
N3/9 CDI control unit
N47-5 ESP and BAS control unit

Networking
- The oil sensor (oil level, temperature and quality) (B40) is read in by the CDI control unit (N3/9) or ME-SFI [ME] control unit (N3/10). The values for oil level, oil temperature and oil condition (oil quality) are sent by the CDI control unit (N3/9) or the ME-SFI [ME] control unit (N3/10) as a message to the Controller Area Network bus Class C (engine compartment) (CAN-C).
- The coolant temperature sensor (B11/4) is read in by the CDI control unit (N3/9) or ME-SFI [ME] control unit (N3/10). The temperature value is sent to the CAN-C in the form of a message.
- The crankshaft position sensor (L5 ) is read in by the CDI control unit (N3/9) or the ME-SFI [ME] control unit (N3/10). The CDI control unit (N3/9) or the ME-SFI [ME] control unit (N3/10) uses the pulses from the sensor to determine the engine speed and sends a corresponding message to the CAN-C

The following rpm sensors are read in by the ESP and BAS control unit (N47-5):
- Left front rpm sensor (L6/1)
- Right front rpm sensor (L6/2)
- Left rear rpm sensor (L6/3)
- Right rear rpm sensor (L6/4)

The ESP and BAS control unit (N47-5) uses the sensor's pulses to determine the wheel speeds and sends corresponding messages to the CAN-C. The instrument cluster (A1) receives these messages and uses them to determine the vehicle speed and the distance traveled.