GF07.61-P-0001MS Motor Electronics (ME-SFI) Fuel Injection and Ignition System, Function

GF07.61-P-0001MS Motor Electronics (ME-SFI) Fuel Injection And Ignition System, Function
- up to model year 08

Component Identification:

The ME-SFI fuel injection and engine electronic ignition system is a further development of the LH-SFI, distributor ignition (EZL) and HFM systems. The complete engine control ME-SFI 2.7.2 is integrated in the ME-SFI [ME] control unit (engine control unit).

The abbreviated designation ME 2.7.2 means:
M = Motronic (motor electronics)
E = Electronic accelerator pedal (electronic accelerator)
2.7.2 = Version 2.7.2

The ME-SFI [ME] control unit is flashable. The software required to program the control units is provided on the DAS Update DVD.

The following functions are combined in the ME-SFI [ME] control unit:
^ Ignition system
^ Injection system
^ Electronic accelerator
^ Idle speed control
^ Torque interface
^ Diagnosis/fault storage/actuation of indicator lamps
^ Gateway between the drive CAN and the chassis CAN
^ Immobilizer/drive authorization
^ Evaporative emission control system ( United States of America with leak test)
^ Actuation of fuel pump (M3) and fuel pressure specification
^ Relay actuation for terminal 87, engine (N10/1kC)
^ Starter control
^ Suction fan control
^ Secondary air injection
^ Boost pressure control
^ Emission control

The ME-SFI [ME] control unit essentially analyzes the following information:
^ Coolant temperature
^ Engine speed and crankshaft position
^ Camshaft position
^ Throttle valve position
^ Charge air temperature
^ Accelerator pedal position
^ O2 sensor signals
^ Vehicle speed (via CAN)
^ Knock identification
^ Fuel pressure
^ Oil level, oil temperature and oil quality
^ Atmospheric pressure (integrated in the ME-SFI [ME] control unit)
^ Air pressure downstream of air filter, right and left cylinder bank
^ Boost pressure (upstream of throttle valve actuator)
^ Intake manifold pressure (downstream of throttle valve actuator)

CAN data bus
The ME-SFI [ME] control unit receives or transmits messages via the following data bus systems:
^ Interior CAN
^ Drive train CAN
^ Diagnostic CAN
^ Chassis CAN
^ Central CAN
^ LIN data bus (for alternator interface)

The central gateway control unit (N93) controls data traffic (gateway) between interior CAN, diagnostic CAN, chassis CAN and central CAN.

ME-SFI [ME] control unit is the gateway between the drive train CAN and chassis CAN.

The following control units are networked via the CAN with the ME-SFI [ME] control unit:
^ EIS [EZS] control unit (N73)
^ ESP control unit
^ Instrument cluster (A1)
^ Steering column module (N80)
^ Fuel pump control unit (N118)
^ Restraint systems control unit (N2/7/)
^ Front SAM control unit with fuse and relay module (N10/1/)
^ Rear SAM control unit with fuse and relay module (N10/2/)
^ AAC [KLA] control unit (N22/1)
^ Electric controller unit (VGS) (Y3/8
^ Central gateway control unit (N93)
^ Intelligent servo module for DIRECT SELECT (A80)

System-wide control units and functions

Electric controller unit (VGS)
Combined action with engine control:
^ Up to 05/2007: report exhaust gas relevant transmission faults to the ME-SFI [ME] control unit
From 06/2007: store exhaust gas relevant transmission faults itself and administer these (independent OBD diagnostic control unit)
^ Torque request for transmission and converter protection
^ Report engaged transmission speed and gear range (as well as P and N) to the ME-SFI [ME] control unit

Steering column module

Component Identification:

Combined action with engine control:
^ Captures signals from the DIRECT SELECT gear selector switch (S40/4), the CC pushbutton switch and the steering angle sensor (N49) and transmits these to the chassis CAN
^ Via a LIN interface, detects actuation of the switch groups on the steering wheel.

Intelligent servo module for DIRECT SELECT

Component Identification:

Combined action with engine control:
^ Part of the drive authorization system (parking shift lock)
^ Mechanical conversion of the electrical drive position request (P, R, N, D) from the DIRECT SELECT gear selector switch (Shift-by-Wire).

Restraint systems control unit

Component Identification:

Combined action with engine control:
^ In the case of front crash, shutoff of the fuel pump (M3)
^ Actuate the fuel injection valves (Y62) shortly to reduce fuel pressure in the case of a front crash.

AAC [KLA] control unit

Component Identification:

Combined action with engine control:
^ Torque request when switching the refrigerant compressor (A9)
^ Effect on idle speed regulation
^ Influence of the suction fan control unit

ESP control unit

Component Identification:

Combined action with engine control:
^ Torque request for ESP
^ For vehicles without DISTRONIC: torque request for cruise control/DISTRONIC
^ Reports when braking is occurring
^ Captures and checks the wheel speeds. These are sent to the instrument cluster and plausibilized. The ME-SFI [ME] control unit receives the wheel speeds via the central CAN, the central gateway control unit and the chassis CAN.

Central gateway control unit

Component Identification:

Combined action with engine control:
^ Controls data traffic between interior CAN, diagnostic CAN, chassis CAN and central CAN.
^ Routing of all fault memories to the data link connector via diagnosis (X11/4)
^ Memory for production date, global variant coding and maintenance computer

Instrument cluster
Combined action with engine control:
^ Communication via the chassis CAN, the central gateway control unit and the central CAN
^ Actuation of the engine diagnosis indicator lamp (A1e58) or for United States of America the CHECK ENGINE indicator lamp (A1e26)
^ For United States of America: actuation of the fuel reserve warning lamp (A1e4) for a gross leak (e.g. if tank cap is missing)
^ Issuing of warning messages in the multifunction display (A1p13) (e.g. engine oil level too low)
^ Transmits information about fuel level, outside temperature and travel distance to the ME-SFI [ME] control unit
^ Reception of current fuel consumption signal for calculation of the fuel consumption
^ Reception of the engine speed signal and coolant temperature.