Gasoline Injection And Ignition System With Direct Injection, Function - GF07.70-P-0002MNG
ENGINE 276.9 in MODEL 166 as of model year 2016
Block diagram for networking the direct line
Block diagram for CAN-networking
Gasoline injection and ignition system with DI, general
The gasoline injection and ignition system with direct injection forms the engine management "MED 17.7.3" in an electrical combination with the sensors and actuators of engine 276.9 DI (D irect Injection). The short designation MED 17.7.3 means:
M = Moronic
E = E lectronic accelerator pedal
D = D irect injection
17.7.3 = Version 17.7.3
The whole engine management is contained in the ME-SFI [ME] control unit.
Sensor data are directly read in from the engine management and indirectly via the CAN network and actuate the control actuators as required. Here the individual functions and systems of the engine management are controlled and coordinated by the ME-SFI [ME] control unit.
The following table represents the model and major assembly overview for engine 276.9:
| Sales designation | Model | Motor | Transmission | Engine management | Notes |
|---|---|---|---|---|---|
| Model series 166 | |||||
| ML 300 4MTIC | 166.055 | 276.955 | 722.906 | MED 17.7.3 | |
| ML 350 4MTIC | 166.057 | 276.955 | 722.906 | MED 17.7.3 | |
| ML 350 | 166.058 | 276.955 | 722.906 | MED 17.7.3 |
The engine management is subdivided into the following systems:
- Base functions
- Engine system
- Fuel injection system
- Ignition system
- Exhaust system
Base functions
- Control unit diagnosis
- Fault memory
- European On-Board Diagnosis
- Diagnosis via CAN
- CAN network
- Flash programming
- Variant coding
- DAS stage 4 (FBS 4)
- Torque coordination
- Thermal management
- Alternator interface
- Maximum speed limit
Diagnosis
For diagnostic purposes, the fault codes of the engine management system can be read out and deleted using Xentry Diagnostics, and individual diagnostic functions can be specifically actuated.
Transport mode
In transport mode various functions of the engine management are limited. Further information are available in the energy management function.
If the kilometer reading of the vehicle is more than 250 km, the system condition "vehicle transport mode" is automatically deactivated and can also not be reactivated anymore using the diagnostic unit.
CAN network
The ME-SFI [ME] control unit exchanges data via the connected drive train CAN, chassis CAN 1 and the drive train sensor CAN with other control units which are integrated in the CAN network. The ME-SFI [ME] control unit also acts as an interface (Gateway) between the two CAN bus systems. It is also connected to the drive train LIN and exchanges data over it.
Flash programming
The engine management in the ME-SFI [ME] control unit is flashable, that is the complete software in the control unit can be replaced using the Xentry diagnostics (replaced). The software required for control unit programming can be found on the diagnostic system software DVD.
Variant coding
With variant coding the following vehicle versions and equipment can, for example, be coded using XENTRY Diagnostics:
- Vehicle model
- National version
- Exhaust variants
- Transmission version
Engine system
- Starter relay actuation
- Throttle valve control
- Safety fuel shutoff
- Transmission overload protection
- Electronic Stability Program control unit support
- Fully integrated transmission control support
- Driving on torque limitation
- Fan control
- Throttle valve calibration
- Intake manifold switchover (selector drum and resonance flaps)
- Regulated adjustment of the intake and exhaust camshafts
- EGR (for code 920 (Gasoline direct injection with stratified charge))
- ECO start/stop function
Fuel injection system
- Cylinder-selective direct injection (with homogeneous operation (DEH (D irekt-E inspritzung H omogenbetrieb (direct injection homogeneous operation)) or homogeneous or stratified operation (DES (D irekt-E inspritzung S chichtbetrieb (direct injection stratified operation)) (for code 920 (Gasoline direct injection with stratified charge))
- Start, post-start phase and acceleration enrichment
- Warm-up control
- Idle speed control
- Limp-home function
- Rpm increase for an activated A/C
- Deceleration fuel shutoff
- Fuel pump controlling
- Altitude adaptation
- Load change function
- Rpm limitation
- Purge system with leak test (with CODE 494 (USA version))
Ignition system
- Multi-spark ignition
- Ignition map
- Rpm limitation
- Knock control
- Synchronization of camshaft and crankshaft position
Exhaust system
- Catalytic converter heating
- Oxygen sensor heater controlling
- Straight-line lambda control
- Purging of NOx storage catalytic converters (for code 920 (Gasoline direct injection with stratified charge))
Homogeneous mode (HID)
In homogeneous mode an homogeneous combustible fuel/air mixture (λ=1) is generated within the whole combustion chamber. There are no further measures required for exhaust aftertreatment since the normal three-way catalytic converter adequately converts the pollutants.
Stratified operation (DIS)
During stratified operation, a combustible mixture (λ 1) is present only in the vicinity of the spark plug (R4) while various lambda values are present in the remaining combustion chamber. This varies from pure intake air through to exhaust gases from the EGR. Thus fuel consumption in stratified operation is less than that in homogeneous mode. Due to the excess air which consists of up to 75% by volume of nitrogen the NOx development in stratified operation is significantly higher than in homogeneous mode. This requires use of a NOx storage catalytic converter.
Homogeneous-layer-company (HOS)
The operating mode HOS shows that it delivers more favorable exhaust emission values in the range above 4 bar than pure stratified operation. At the same time it allows replacement of the homogeneous mode up to about 7 bar, whereby major consumption savings are achieved.
HOS is a combination of the homogeneous lean and classic stratified combustion system. Here for a de-throttled engine, the first injection is injected in the intake stroke; the actual "layer" injection takes place before ignition.
The following table represents the different components on engine 276.9 (DEH) and 276.9 (DES):
| Components | M 276.9 DEG | M 276.9 DIS |
|---|---|---|
| Hot film MAF sensor (B2/5) | - | x |
| Intake air temperature sensor (B2/5b1) | - | x |
| Intake air temperature sensor (B17) | x | - |
| Temperature sensor upstream of the right NOx storage catalytic converter (B16) | - | x |
| Temperature sensor upstream of left NOx storage catalytic converter (B16/1) | - | x |
| Left NOx sensor control unit (N37/5) | - | x |
| Left NOx sensor (N37/5b1) | - | x |
| Right NOx sensor control unit (N37/6) | - | x |
| Right NOx sensor (N37/6b1) | - | x |
| Left exhaust gas recirculation valve (Y27/11) | - | x |
| Left exhaust gas recirculation valve Hall sensor (Y27/11b1) | - | x |
| Left exhaust gas recirculation valve rotating solenoid (Y27/11y1) | - | x |
| Right exhaust gas recirculation valve (Y27/12) Right exhaust gas recirculation valve Hall sensor (Y27/12b1) | - | x |
| Right exhaust gas recirculation valve rotating solenoid (Y27/12y1) | - | x |
| Exhaust removal pipes, left and right | - | x |
The operating conditions of the engine and the associated active partial functions of the engine management are described in the following documents:
| Ignition ON, function | GF07.10-P-1000MNG | ||
| Starting, function | GF07.10-P-1001MNG | ||
| Ignition OFF, function | GF07.10-P-1002MNG | ||
| Fuel supply, function | GF07.10-P-1003MNG | ||
| Injection regulation, function | GF07.10-P-1004MNG | ||
| Ignition system function | GF07.10-P-1005MNG | ||
| Synchronize fuel injection and firing order function | GF07.10-P-1006MNG | ||
| Start, post-start phase and warm-up enrichment, function | GF07.10-P-1007MNG | ||
| Rpm control, function | GF07.10-P-1008MNG | ||
| Alternator interface function | GF07.10-P-1009MNG | ||
| Lambda control, function | GF07.10-P-1010MNG | ||
| Smooth running control, function | GF07.10-P-1011MNG | ||
| Thermal management, function | GF07.10-P-1012MNG | ||
| Torque coordination, function | GF07.10-P-1013MNG | ||
| Deceleration fuel shutoff, function | GF07.10-P-1014MNG | ||
| Knock control, function | GF07.10-P-1015MNG | ||
| Camshaft adjustment, function | GF07.10-P-1016MNG | ||
| Intake manifold switchover, function | GF07.10-P-1017MNG | ||
| Engine limp-home mode, function | GF07.10-P-1019MNG | ||
| European OBD, function | GF07.10-P-1021MNG | ||
| ECO start/stop function engine management, function | The "ECO start/stop function engine management" partial function is seen from the point of view of the engine management. Information for the partial function "ECO start/stop function energy management" is documented in the function description "Energy management function". | GF07.10-P-1042MNG | |
| Exhaust treatment function | GF14.00-P-3000MNG | ||
| Exhaust gas recirculation, function | ENGINE 276.9 in MODEL 166 as of model year 2016 with CODE 920 (Direct petrol injection with stratified charging) | GF14.20-P-3000MNG | |
| Electronic accelerator function | GF30.20-P-3015MNG | ||
| On-board refueling vapor recovery function | ENGINE 276.9 in MODEL 166 as of model year 2016 with CODE 494 (US version) | GF47.10-P-3004MNG | |
| Purging function | GF47.30-P-3015MNG | ||
| Purge system with leak test, function | ENGINE 276.9 in MODEL 166 as of model year 2016 with CODE 494 (US version) | GF47.30-P-3017MNG | |
| Overview of system components for gasoline injection and ignition system with direct injection | GF07.70-P-9998MNG |