ME-SFI [ME] control unit, component description

P07.61-3632-11

View of engine from left front

N3/10 ME-SFI [ME] control unit

Location

The ME control unit is located on the left at the air filter housing.

Task

The ME-SFI [ME] control unit creates the engine control in electrical connection with the sensors and actors of engine 271 KE .

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

- Charge pressure control

- Heat management

- Torque interface

- Alternator interface

- Emission control

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Input and output signals

The following input signals are evaluated by the engine control and issued in the respective output signals:

 Direct input signals

 Direct output signals

 LIN signals

 CAN input signals

 CAN output signals

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Direct input signals

- Tml. 15

- Circuit 30 (fused)

- Tml. 31

- Circuit 87M1

- Crash signal from the restraint system control unit (N2/7)

- Knock sensor (A16)

- Hot film mass air flow sensor (B2/5)

- Left intake camshaft Hall sensor (B6/4)

- Right exhaust camshaft Hall sensor (B6/7)

- Coolant temperature sensor (B11/4)

- Intake air temperature sensor (B17)

- Pressure sensor (intake manifold air pressure) (B28)

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- Accelerator pedal sensor (B37) - potentiometer 1

- Accelerator pedal sensor - potentiometer 2

- O2 sensor downstream of CAT (G3/1) (non-linear oxygen sensor)

- O2 sensor upstream of CAT (G3/2) (wideband oxygen sensor)

- Crankshaft position sensor (L5)

- Throttle valve - actual value potentiometer 1 (M16/6r1)

- Throttle valve - actual value potentiometer 2 (M16/6r2)

- Air recirculation flap - actual value potentiometer 1 (M16/7r1)

- Air recirculation flap - actual value potentiometer 2 (M16/7r2)

- Crash signal from the restraint system control unit (N2/7)

- Clutch pedal switch (S40/3) (for manual transmission)

- Oil level indicator switch (S43)

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Direct output signals

- Sensor voltages 1 and 2 (5 V) - engine plug

- Sensor voltages 1 and 2 (5 V) - vehicle plug

- Sensor grounds 1 and 2 - engine plug

- Sensor ground 1 - vehicle plug

- Accelerator pedal sensor - reference ground for potentiometer 1

- Accelerator pedal sensor - reference ground for potentiometer 2

- O2 sensor upstream of CAT - oxygen sensor heater

- O2 sensor downstream of CAT - oxygen sensor heater

- Engine and air conditioning electric suction fan with integrated control (M4/7) - specified speed of the fan

- Throttle valve - actuator motor (M16/6m1) +

- Throttle valve - actuator motor (M16/6m1) -

- Air recirculation flap - actuator motor (M16/7m1) +

- Air recirculation flap - actuator motor (M16/7m1) -

- Circuit 87 relay, engine (N10/1kR)

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- Starter relay (N10/1kS)

- Fuel pump relay (N10/2kA)

- Cylinder 1 ignition coil (T1/1)

- Cylinder 2 ignition coil (T1/2)

- Cylinder 3 ignition coil (T1/3)

- Cylinder 4 ignition coil (T1/4)

- Air pump changeover valve (Y32)

- Intake camshaft solenoid (Y49/1)

- Exhaust camshaft solenoid (Y49/3)

- Purge control valve (Y58/1)

- Cylinder 1 fuel injection valve (Y62y1)

- Cylinder 2 fuel injection valve (Y62y2)

- Cylinder 3 fuel injection valve (Y62y3)

- Cylinder 4 fuel injection valve (Y62y4)

- TNA signal (engine speed signal)

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LIN signals

- Alternator interface via drive LIN (LIN C1)

CAN input signals

Instrument cluster (A1)

- Fuel reserve signal

Restraint systems control unit (N2/7)

- Crash signal

ETC control unit (N15/3) (for automatic transmission)

- Drive position

- Transmission mode

- Actual gear, target gear

- Engine torque reduction request

- 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 transmission control

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Comfort AAC [KLA] control and operating unit (N22/7)

- Specified fan speed request

- Engine torque request

ESP and BAS control unit (N47-5)

- Vehicle speed

- Wheel speed signal

- Brake recognition

- Cruise control request

- Engine torque request

EIS control unit (N73)

- Start enable (drive authorization system)

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CAN output signals

Instrument cluster (A1)

- 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))

EIS control unit (N73)

- Start query (drive authorization system)

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ETC control unit (N15/3) (for automatic transmission)

- Requests for catalytic converter heating

- Switching request

- Engine torque

- Engine coolant temperature

- Engine oil temperature (from temperature model)

- Engine speed

- Engine load

- Kickdown

- Engine speed limitation active

- Limp-home mode engine control

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Design

The housing of the ME-SFI [ME] control unit is made out of diecast aluminum and the cover is made out of corrosion-proof sheet steel. The ME-SFI [ME] control unit is protected against water and dusts.

The housing contains the 32-bit measuring and control electronics for the engine control.

Voltage supply

The ME-SFI [ME] control unit is "circuit 30 secured" and also supplied with voltage for ignition ON by "circuit 87 M1.2" .

It is fitted in the operating voltage range with short-circuit protection as well as reversed polarity protection.

In certain cases voltage is supplied through several pins connected in parallel by to relief the electrical connectors.

Ground connection

The "tml. 31" ground connection is made through several ground lines from the electronic ground of the LH major assemblies compartment (W16/5).

Computer run-on

If the ME-SFI [ME] control unit receives the signal "circuit 15 OFF" a processor run-on of approx. 5 seconds is started.

It can however take a number of minutes due to various function (such as OBD, DAS 3, 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 control unit and save errors in the control units linked to the CAN.

Variants

The variant of the engine control, such as national and exhaust variants, are activated with the DAS over variant coding.

Replacement of the ME-SFI [ME] control unit is not necessary.