Version ME2.0 and ME2.8
ME-SFI [ME] vehicle features
Version ME2.0 and ME2.8
Engine 112.91/92/94/95/97
Engine 113.94/96
Control unit ME 2.0
Control unit ME 2.0 with 6 connectors (A - F), input and output signals matched.
Control unit ME 2.8 as of approx. 06/00
Control unit ME 2.8 with 5 connectors (1 up to 5). The aluminium ME control unit is designed as a shell concept standard housing.
Input signals from the following sensors:
- Coolant temperature sensor
- Intake air temperature sensor (integrated in hot film mass air flow sensor)
- Hot film mass air flow sensor
- Throttle valve actuator (actual value potentiometer)
- Oil sensor (oil level/oil temperature/oil quality)
- Variable cruise control switch/cruise control switch (USA)
- Circuit 50 of electronic ignition switch control unit (start recognition)
- P/N information from ETC control unit
- Clutch pedal switch (manual transmission)
- Reversing light switch (manual transmission)
- Fuel tank pressure sensor (USA)
- Intake manifold pressure sensor for national version (USA) in the case of cylinder shutoff and in the case of ME 2.8 as of 06/00
- Crankshaft position sensor (incremental)
- Camshaft Hall sensor
- O2 sensors
- Knock sensors
- Accelerator pedal sensor (set value potentiometer)
Output signals:
- Actuation of ignition coils (one double ignition coil for each cylinder)
- Actuation of fuel injectors
- Actuation of throttle valve actuator
- Actuation of fuel pump relay
- Output of PWM signal for exhaust gas recirculation/vacuum transducer
- Actuation of secondary air injection
- Actuation of intake manifold switchover
- Actuation of purge control valve
- Actuation of O2 sensor heater
- Output of TNA engine speed signal
- Actuation of activated charcoal filter shutoff valve (USA)
- Output PWM signal for the fan control unit (phased in, production start-up with viscous fan)
- Actuation of starter relay
- Data line for fault memory.
Information relating to CAN databus:
- BAS/ESP or BAS/ASR operating states
- ETC operating states
- Operating conditions SBC
- Electronic accelerator pedal operating states
- ASR/ESP engine specified torque reduction/increase
- ETC torque interface
- Gear recognition
- Transmission overload protection
- Wheel speeds (vehicle speed and acceleration)
- Brake light switch
- Instrument cluster (indicator lamps, warning signal, oil level, oil temperature, oil quality, fuel system open warning (USA), fuel consumption signal, coolant temperature, intake air temperature, engine speed)
- AC compressor ON/OFF, refrigerant pressure
Ignition system
The engines are equipped with double ignition. Two spark plugs for each cylinder are beneficial because of the arrangement of the valves for achieving optimal emission levels and smooth engine running.
Each spark plug is actuated separately by its own ignition coil by the engine control unit. Both ignition coils of a cylinder are combined to form a dual ignition coil.
In the lower part load range up to approx. 2000 rpm both ignition sparks of a cylinder are triggered simultaneously. At moderate and high engine loads, the ignition sparks are triggered offset by as much as 10� crank angle. Here the order in which actuation takes place is constantly changed in order to achieve even wear on both spark plugs and to prevent one sided deposits in the combustion chamber.
Coolant temperature sensor
More compact design with matching plug connection. Inserted into a hole from the front in middle of engine and sealed with O-ring. Attached by means of spring clasp.
Oil sensor (oil level, oil temperature, oil quality)
The oil level, oil temperature and oil quality arer detected by means of an oil sensor installed in the oil pan. The sensor operates in accordance with the capacitive measuring principle and features integrated electronics which detects the three signals. The information is passed in the form of a PWM signal to the ME control unit and over the CAN to the instrument cluster.
The oil quality is detected for the demand-based oil change interval display. The oil quality is detected on the basis of the capacitance of the engine oil (dielectrics), this being as much as 6 times greater in the case of poor oil quality.
The measuring range for the oil level is 80 mm (normal level ±0 mm), measurement accuracy approx. ±3 mm. The voltage supply of the oil sensor is performed by the ME control unit.
O2 sensors upstream of TWC
An O2 sensor is screwed into the front exhaust pipe close to the engine in each exhaust line. The lambda control is performed separately between the right-hand and left-hand bank of cylinders.
O2 sensors downstream of TWC (USA) and low emission EURO3/4
The O2 sensors downstream of the TWC are already positioned downstream of the firewall catalytic converters.
Intake manifold switchover
On engines 112, 113 the intake manifold is switched over between a long and short intake passage by means of a pneumatically operated flap positioned at the front of the intake manifold in order to improve torque. The resonance intake manifold switchover valve is operated in this case by the ME control unit.
Fuel supply
The fuel return flow lilne and the diaphragm pressure regulator at the fuel rail are discontinued (single-line system). The fuel pressure regulator is now integrated in the fuel filter. Excess fuel flows back from the fuel filter into the fuel tank.
There is a fuel pump (helical spindle pump) installed on the fuel pump assembly or a two-stage fuel pump in the fuel delivery module (types 163, 203, 209, 211).
Secondary air injection (USA) and low emission EURO3/4
The electric air pump is positioned at the front of the engine. A combination valve (air shutoff valve and check valve) is flanged to the front of the cylinder head of each bank of cylinders. The air pump switchover valve is operated parallel to the electric air pump.
Exhaust gas recirculation
A combined exhaust gas recirculation valve with electric vacuum transducer is installed behind the right bank of cylinders. The vacuum transducer is actuated by the ME/HMS control unit by means of a PWM signal. It is actuated in line with the map as a function of engine speed, engine load, coolant temperature, idling speed and full throttle detection.
The EGR valve is opened to a varying extent as a result of this actuation with a vacuum of approx. 80 to 220 mbar and the quantity of exhaust gases which are recirculated, is controlled in this way. This results in a further reduction in the formation of NOX.
Speedtronic (without (USA))
Additional cruise control functions are the variable vehicle speed limiter and the individually programmable permanent maximum speed. This requires a variable cruise control switch (S40/4) with a sliding switch.
The switching signals from the variable cruise control switch are transmitted over the CAN databus to the ME control unit.
Evaporative emission control system (USA)
Activated charcoal canister enlarged. Purge system with leak test.
Fuel system (USA)
During refueling the fuel vapors are collected at the filler neck and passed to the activated charcoal filter (ORVR = Onboard Refueling Vapor Recovery). The system is not envisaged for model 163.
Exhaust system (USA) and low emission EURO3/4
A firewall catalytic converter is installed in each exhaust line.
ME 2.8 as of 06/00
Engines 112 and 113 are equipped with the new ME 2.8 fuel injection and ignition system (successor of ME 2.0). New are:
- Housing of ME-SFI control unit and contacts modified
- Intake manifold pressure sensor (B28) for altitude detection at engine start and for testing exhaust gas recirculation
- Throttle valve actuator with modified contacts
- O2 sensors of type LSH 4.7 (Bosch). The sensor heating output is approximately 7 watts when warm (previously 18 watts).
- Exhaust gas concept EURO3/4
Flexible Fuel Vehicle (FFV) (USA)
Engine 112.946 from 15/7/02 with code 929
FFV-vehicles can be fueled with premium fuel or with Ethanol (portion of Ethanol 85 %). This results in mixtures with a portion of ethanol in the fuel tank from %0% to %85% The ethanol contentl is taught in after each filling of the fuel tank and mixture creation is adjusted accordingly.