Common Rail Diesel Injection (CDI), Function - GF07.16-P-0001OLG
ENGINE 651.9 up to 2/28/13 in MODEL 166 up to model year 2016
Common rail diesel injection (CDI) - general
The Common-Rail Diesel Injection (CDI) with its electrical connections to the sensors and actuators of engine 651 creates the engine management "CR-DIII" up to 28.02.2013 and engine management "CR43" as of 01.03.2013.
The short designation "CR-DIII" means:
CR = Common Rail
D = Delphi (manufacturer of the diesel injection system)
III = 3rd generation
The "common rail" is the line shared by all injectors for fuel delivery. The fuel upstream of the injection is stored in this common line.
Therefore a common rail system is also called "storage injection".
The entire engine management system is located in the CDI control unit (N3/9). Sensor data are directly read in from the engine management and indirectly via the CAN network and actuate the control actuators as required. The individual functions and systems of the engine management are controlled and coordinated by the CDI control unit.
The following table provides an overview of the vehicle model and major assembly overviews:
| Sales designation | Model | Motor | Transmission | Engine management | Notes |
|---|---|---|---|---|---|
| Model series 166.0 | |||||
| ML 250 4MATIC | 166.003 | 651.960 | 722.908 | CR-DIII | |
| ME 250 BlueTEC 4MATIC | 166.004 | 651.960 | 722.908 | CR-DIIICR43 |
The engine management is subdivided into the following systems:
- Base functions
- Engine system
- Diesel injection system
- Air control system
- Exhaust system
Base functions
- Control unit diagnosis
- Fault memory
- OBD II (OBD II)
- Diagnosis through C ontroller A rea N etwork (CAN)
- CAN network
- Flash programming and variant coding
- Drive authorization system stage 3 (DAS 3)
- Torque coordination
- Thermal management
- Alternator interface
- Synchronization
- Load determination
Diagnosis
For diagnostic purposes, the fault codes from the engine management can be read out and deleted with Xentry Diagnostics, and specific diagnostic functions initiated.
Transport mode
In transport mode various functions of the engine management are limited. Further information is 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 tester.
Variant coding
With variant coding the following vehicle versions and equipment can, for example, be coded using XENTRY Diagnostics:
- Vehicle model
- National version
- Exhaust variant
- Transmission version
Flash programming
The engine management in the CDI control unit is flashable, i.e. the entire software of the control unit can be exchanged (replaced) using Xentry Diagnostics. The software required for control unit programming can be found on the Xentry Diagnosis software DVD.
CAN network
The CDI control unit exchanges data via the connected drive train CAN (CAN C), chassis CAN 1 (CAN E1) and drive train sensor CAN (CAN I) (with code U42 (BLUETEC (SCR) diesel exhaust treatment) with other control units integrated in the CAN network. The CDI control unit also acts as the interface (gateway) between the three CAN bus systems.
The CDI control unit is also connected to the drive train LIN (LIN C1) and exchanges data over it.
Engine system
- Start relay actuation
- Throttle valve control
- Safety fuel shutoff
- Transmission overload protection
- Electronic Stability Program control unit support
- Fully integrated transmission control support
- Drive off torque limitation and anti-jerk control
- Fan control
- Alternator regulation and glow time control
- Engine management start/stop function (with code B03 (ECO start/stop function))
Diesel injection system
- Pre, main and post injection
- Idle speed control
- Rpm limitation
- Smooth running control
- Limp-home function
- A/C rpm increase
- Deceleration fuel shutoff
- Rail pressure regulation
- Fuel pump controlling
- High-pressure pump control
- Altitude adaptation
Air control system
- Exhaust gas recirculation (EGR)
- Boost pressure control
- Intake air throttling through intake port shutoff (EKAS)
Exhaust system
- Catalytic converter heating
- Oxygen sensor heater controlling
- Exhaust aftertreatment, DPF regeneration (Diesel Particulate Filter) (with code 474 (Particulate filter))
- Exhaust aftertreatment, injection of AdBlue® reduction agent (with code U42 (BlueTEC (SCR) diesel exhaust treatment))
Engine 651.9 complies with the EU-5 exhaust emissions standard.
Vehicles with code U42 (BlueTEC (SCR) diesel exhaust treatment fulfill the EU-6 exhaust emissions standard or the BIN5 LEVII exhaust emissions standard for the USA.
Engine 651 is characterized by the following components:
- 2 Balance shafts
- The oil pump integrated in the crankcase
- Gearwheel drives in combination with a timing chain on the flywheel side for driving the high-pressure pump, oil pump, balance shafts and the two camshafts
- Oil spray nozzle shutoff valve (Y131) for controlling the oil spray nozzles for piston crown cooling
- Switchable coolant pump
- Exhaust gas recirculation (EGR) with coolant-cooled pre-cooler and EGR cooler with switchable bypass duct
- Cylinder head with 2-piece water jacket
- Rapid glowing system with glow output stage (N14/3)
- Load-level controlled preinjection and post injection
- Fuel injectors with piezo technology, 2 turbochargers connected in series with vacuum-controlled boost pressure control flap, a wastegate, a charge air bypass flap and an additional low-pressure low-pressure turbocharger (B5/4)
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
- Starting, function
- Ignition OFF, function
- Fuel supply, function
- Injection regulation, function
- Rpm control, function
- Alternator interface, function
- Smooth running control, function
- Thermal management, function
- Torque coordination, function
- Deceleration fuel shutoff, function
- Engine limp-home mode, function
- European OBD, function
- Engine management Start-Stop function
- Forced induction, function
- Exhaust treatment, function
- Exhaust gas recirculation, function
- Preheat, function
| Ignition ON, function | GF07.10-P-1000OLG | ||
| Starting, function | GF07.10-P-1001OLG | ||
| Ignition OFF, function | GF07.10-P-1002OLG | ||
| Fuel supply, function | GF07.10-P-1003OLG | ||
| Injection regulation, function | GF07.10-P-1004OLG | ||
| Rpm control, function | GF07.10-P-1008OLG | ||
| Alternator interface function | GF07.10-P-1009OLG | ||
| Smooth running control, function | GF07.10-P-1011OLG | ||
| Thermal management, function | GF07.10-P-1012OLG | ||
| Torque coordination, function | GF07.10-P-1013OLG | ||
| Deceleration fuel shutoff, function | GF07.10-P-1014OLG | ||
| Engine limp-home mode, function | GF07.10-P-1019OLG | ||
| On-board diagnosis, function | GF07.10-P-1020OLG | ||
| Engine timing start-stop function | ENGINE 651.9 in MODEL 166 up to model year 2016 with CODE B03 (ECO start/stop function) The "engine management for start/stop function" subfunction is considered from the viewpoint of the engine management. Information for partial function "Energy management, start/stop function" is documented in the function description "Energy management function". |
GF07.10-P-1041OLG | |
| Charging, function | GF09.00-P-2000OLG | ||
| Exhaust treatment function | GF14.00-P-3000OLG | ||
| Exhaust gas recirculation, function | GF14.20-P-3000OLG | ||
| Preheat, function | GF15.20-P-3005OLG | ||
| Overview of system components for common rail diesel injection (CDI) | GF07.16-P-9997OLG |