Location
The ME-SFI control unit (N3/34) is installed to the right of the engine compartment.
S07.61-4533-06
Task
The ME-SFI [ME] control unit (N3/34) fulfills the following tasks:
Controlling the engine basic functions
Reading in of signals
Evaluation of input factors
Output of signals and actuation of components
Controlling the engine basic functions
Ignition
Start
Fuel supply
Injection control
Ignition system
Synchronization of injection and firing order
Start, post-start phase and warm-up enrichment
Engine speed control
Alternator interface
Lambda control
Torque coordination
Inertia fuel shutoff
Knock sensor system
Camshaft adjustment
European On-Board Diagnosis
Exhaust aftertreatment
The ME-SFI control unit (N3/34) has an internal atmospheric pressure sensor.
Input and output signals
The following input signals are evaluated by the ME-SFI control unit (N3/34) and the appropriate output signals are issued:
Direct input and output signals
CAN signals
Direct input signals
The ME-SFI control unit (N3/34) reads in the signals from the following components:
Knock sensor (A16)
Hot film mass air flow sensor (B2/8)
Intake camshaft position sensor (B6/15)
Exhaust camshaft position sensor (B6/16)
Coolant temperature sensor (B11/17)
Refrigerant pressure sensor (B12)
Exhaust temperature sensor upstream of ATL (B17/7)
Intake manifold pressure sensor (B28/15)
Accelerator pedal module (B37/4)
Engine oil temperature sensor (B40/9)
Oil pressure sensor (B40/11)
Crankshaft Hall sensor (B70/2)
Oxygen sensor downstream of catalytic converter (G3/1)
Oxygen sensor upstream of catalytic converter (G3/2)
Throttle valve actuator (M16/6)
Clutch pedal switch (S40/3)
Intake camshaft solenoid (Y49/10)
Exhaust camshaft solenoid (Y49/11)
Direct output signals
The ME-SFI CDI control unit (N3/34) directly actuates the following components:
Throttle valve actuator (M16/6)
Activated charcoal canister shut-off valve (Y57)
Ignition coils (T1)
Fuel injectors (Y62)
CAN signals
To do this the ME-SFI control unit (N3/34) communicates via the vehicle CAN (CAN I) with the following control units:
Instrument cluster (IC) control unit (A1/1) via the central gateway (CGW) (N93) and user interface CAN (CAN HMI)
Supplemental restraint system control unit (SRS) (N2/18),
Signal acquisition and actuation module (SAM) control unit (N10/1)
Climate control control unit (N154)
Electronic Stability Program control unit (ESP) (N30/4)
Fuse and relay module (SRM) control unit (N50)
Steering column tube module control unit (MRM) (N80) via the central gateway (CGW) (N93) and chassis CAN (CAN E)
Control of the ignition system
The ME-SFI control unit (N3/34) actuates the ignition coils (T1):
Cylinder 1 ignition coil (T1/11)
Cylinder 2 ignition coil (T1/12)
Cylinder 3 ignition coil (T1/13)
Cylinder 4 ignition coil (T1/14)
Fuel supply
The ME-SFI control unit (N3/34) actuates the fuel pump relay (N50k8) and thus the fuel pump with fuel feed module(M3/3) via the fuse and relay module (SRM) (N50), which supplies the fuel to the fuel injectors (Y62).
Injection quantity control
The ME-SFI control unit (N3/34) actuates the fuel injectors (Y62) rotational speed and load-dependent:
Cylinder 1 fuel injector (Y62/31)
Cylinder 2 fuel injector (Y62/32)
Cylinder 3 fuel injector (Y62/33)
Cylinder 4 fuel injector (Y62/34)
Structure
The housing of the ME-SFI [ME] control unit (N3/34) is made out of diecast aluminum and the cover is made out of corrosion-proof sheet steel. The ME-SFI [ME] control unit (N3/34) is water proof and dust proof.
Ground connection
"Circuit 31" ground connection is connected through multiple ground lines to the engine ground point (W11/3).
Variants
The variants of the engine management, such as the country and exhaust variants, are activated over the variant coding; the MI-SFI control unit (N3/34) does not have to be replaced for this.