ENGINE | 273.9 in MODEL 207.3/4, 212.0/2 |
View of the engine compartment from the front (shown on model 212) |
N3/10 | ME-SFI [ME] control unit |
P07.61-3613-11
Location
The ME-SFI [ME] control unit is located in the middle on the variable intake manifold.
Task
The ME-SFI [ME] control unit creates in an electrical combination with the sensors and actuators of engine 273 DE (Direct-Injection) the engine timing.
The following systems and functions are controlled and coordinated by the ME-SFI [ME] control unit according to input signals:
– ignition system
- fuel supply
- injection control
– electronic accelerator
- diagnosis and fault storage
- drive authorization system and immobilizer
– regulated camshaft adjustment
- intake manifold and tumble flap switchover
– thermal management
- torque interface
- alternator interface
- exhaust gas cleaning
Input and output signals
The following input signals are evaluated by the engine timing system and respective output signals are issued:
Direct input signals
Direct output signals
LIN signals
CAN input signals
CAN output signals
Direct input signals
– circuit 15
- circuit 30 (fused)
– circuit 31
– circuit 87 M1
– knock sensor on the right (A16/1)
– knock sensor on the left (A16/2)
– hot film MAF sensor (B2/5)
- intake air temperature sensor (B25b1)
- fuel tank pressure sensor (B4/3) (with code (494) USA version)
- left intake camshaft Hall sensor (B6/4)
- right intake camshaft Hall sensor (B6/5)
- left exhaust camshaft Hall sensor (B6/6)
- right exhaust camshaft Hall sensor (B6/7)
– coolant temperature sensor (B11/4)
– pressure sensor (B28) (intake manifold air pressure)
– left intake manifold tumble flap position sensor (B28/9)
– right intake manifold tumble flap position sensor (B28/10)
– accelerator pedal sensor (B37) - potentiometer 1
– accelerator pedal sensor - potentiometer 2
– crankshaft Hall sensor (B70)
- LH oxygen sensor upstream of catalytic converter (G3/3) (wideband oxygen sensor)
- RH oxygen sensor upstream of catalytic converter (G3/4) (wideband oxygen sensor)
- LH oxygen sensor downstream of catalytic converter (G3/5) (non-linear oxygen sensor)
- RH oxygen sensor downstream of catalytic converter (G3/6) (non-linear oxygen sensor)
– throttle valve - actual value potentiometer 1 (M16/6r1)
– throttle valve - actual value potentiometer 2 (M16/6r2)
– crash signal from supplemental restraint system control unit (N2/10)
– oil level check switch (S43)
Direct output signals
- sensor voltages 1 and 2 (5 V) - engine connector
- sensor voltages 1 and 2 (5 V) - vehicle connector
- sensor grounds 1 and 2 - engine connector
- sensor ground 1 - vehicle connector
- accelerator pedal sensor - reference mass for potentiometer 1 and 2
- LH oxygen sensor upstream of catalytic converter - oxygen sensor heater
- RH oxygen sensor upstream of catalytic converter - oxygen sensor heater
- LH oxygen sensor downstream of catalytic converter - oxygen sensor heater
- RH oxygen sensor downstream of catalytic converter - oxygen sensor heater
- fan motor for internal combustion engine and air conditioning system with integrated control (M4/7) - specified fan speed
– throttle valve - actuator motor (M16/6m1) (Plus)
– throttle valve - actuator motor (M16/6m1) (Minus)
– circuit 50 relay, starter (N10/1kM)
– engine circuit 87 relay (N10/1kN)
– secondary air injection relay (N10/1kP)
– fuel system control unit (N118) - fuel pump ON ground signal
– cylinder 1 ignition coil (T1/1)
– cylinder 2 ignition coil (T1/2)
– cylinder 3 ignition coil (T1/3)
– cylinder 4 ignition coil (T1/4)
– cylinder 5 ignition coil (T1/5)
– cylinder 6 ignition coil (T1/6)
– cylinder 7 ignition coil (T1/7)
– cylinder 8 ignition coil (T1/8)
– intake manifold switchover valve (Y22/6)
– intake manifold tumble flap switchover valve (Y22/9)
– air pump switchover valve (Y32)
- left intake camshaft solenoid (Y49/4)
- right intake camshaft solenoid (Y49/5)
- left exhaust camshaft solenoid (Y49/6)
- right exhaust camshaft solenoid (Y49/7)
– purging switchover valve (Y58/1)
- activated charcoal canister shutoff valve (Y58/4) (with code (494) USA version)
- cylinder 1 injection valve (Y62/1)
- cylinder 2 injection valve (Y62/2)
- cylinder 3 injection valve (Y62/3)
- cylinder 4 injection valve (Y62/4)
- cylinder 5 injection valve (Y62/5)
- cylinder 6 injection valve (Y62/6)
- cylinder 7 injection valve (Y62/7)
- cylinder 8 injection valve (Y62/8)
– coolant thermostat (Y110)
LIN signals
– alternator interface via the drive LIN (LIN C1)
CAN input signals
Instrument cluster (A1)
- fuel reserve signal
Supplemental restraint system control unit (N2/10)
- crash signal
Electronic Stability Program control unit (N30/4) (except code (233) DISTRONIC PLUS) or
Premium Electronic Stability Program control unit (N30/7) (for code (233) DISTRONIC PLUS)
- vehicle speed
– wheel speed signal
- brake recognition
– cruise control request
– engine torque request
Automatic climate control control and operating unit (N22/7)
– specified fan speed request
- air conditioning status
Radar sensors control unit (N62/1) with code (233) Distronic Plus)
– engine torque request
Electronic ignition lock control unit (N73)
- start enable (drive authorization system)
Fully integrated transmission control controller unit (Y3/8)
- drive position
- transmission mode
- actual gear, target gear
- engine torque request (reduction)
- starter enable in selector lever position "P", "N"
- engine idle specified speed (for actuation of the torque converter lockup clutch)
- status of torque converter lockup clutch
- emergency operation transmission control
Fuel system control unit (N118)
– fuel pressure
– self-diagnosis data
– requested diagnostic data
CAN output signals
Instrument cluster
– engine oil level too low
- circuit 61 signal (generated by ME-SFI [ME] control unit)
– fuel consumption (the trip computer is informed about the current fuel consumption by means of square-wave pulse packages (1 pulse = 0.2 l/h))
Electronic ignition switch control unit
– start enable request (drive authorization system)
Fully integrated transmission control control unit
Requests for catalytic converter heating
Switching request
- engine torque
- engine coolant temperature
- engine oil temperature
- engine speed
- engine load
- kickdown
- engine speed limitation active
- limp-home mode engine timing
fuel system control unit
– fuel pump ON
– fuel requirements
- diagnosis request
Body
The housing of the ME-SFI [ME] control unit is made out of die cast aluminum and the cover is made out of corrosion-proof sheet steel. The ME-SFI [ME] control unit is protected against water and dust.
The housing contains the 32-bit measuring and control electronics for the engine timing.
Voltage supply
The ME-SFI [ME] control unit is "circuit 30 fused" and also supplied with a voltage for ignition ON by "circuit 87 M1" .
In the operating voltage range it has both short-circuit protection and reversed polarity protection.
Power is supplied through several pins connected in parallel to relieve the electrical connectors.
Ground connection
The "circuit 31" ground connection is made via several ground lines to the left major assembly compartment electronics ground point (W16/5).
Computer power-down
If the ME-SFI [ME] control unit receives the signal "circuit 15 OFF", a processor run-on of approx. 5 seconds is started.
However, it may also last for several minutes due to various functions (for example, on-board diagnosis (OBD), drive authorization system (DAS), thermal management).
Assembly operations
Ensure before unplugging the plug on the ME-SFI [ME] control unit that the ignition is switched off and computer run-on has ended. This is to prevent damage to the ME-SFI [ME] control unit and save errors in the control units linked to the CAN.
Variants
The engine timing variants (e.g. national and exhaust variants) are activated with Xentry Diagnostics using the variant coding function.
Replacement of the ME-SFI [ME] control unit is not necessary.