GF07.16-P-0001OG Common Rail Diesel Injection (CDI), Function
GF07.16-P-0001OG Common Rail Diesel Injection (CDI), Function
ENGINES 642.830 in MODEL 204.025 /225
ENGINES 642.832 in MODEL 204.092 /292 /992
ENGINES 642.834 in MODEL 204.023 /223
ENGINES 642.835 in MODEL 204.993
ENGINES 642.836 in MODEL 207.322 /422
ENGINES 642.838 in MODEL 207.323 /423
ENGINES 642.850 in MODEL 212.020 /024 /025 /220 /224 /225
ENGINES 642.852 in MODEL 212.023 /223
ENGINES 642.853 /854 in MODEL 218
ENGINES 642.856 in MODEL 212.089 /289
ENGINES 642.858 in MODEL 212.093 /293
Common rail diesel injection (CDI), general
The Common-Rail Diesel Injection (CDI) forms the engine timing "CR-6+" as an electrical network in combination with sensors and actuators on engine 642.8 and the engine timing "CR-60" for vehicles with code (B03) ECO start/stop function or increased engine power (195 kW).
Short cuts "CR-6+" and "CR-60" mean:
CR = Common rail
6+ = CDI 6+ the fourth generation of diesel direct injection technology
60 = CDI 60 the fourth generation of diesel direct injection technology
The "common rail" is the line shared by all injectors for fuel delivery. In this common rail, the fuel is stored temporarily before injection. Therefore a common rail system is also called "storage injection".
The entire engine control system is located in the CDI control unit (N3/9).
Sensor data is directly read in from the engine control and indirectly via the CAN network and actuates the control elements as required. The individual functions and systems of the engine control system are controlled and coordinated by the CDI control
The following table provides an overview of the vehicle models and installed major assemblies:
The engine control is subdivided into the following systems:
^ Basic functions
^ Engine system
^ Injection system
^ Air control system
^ Exhaust system
Basic functions
- Control unit diagnosis
- Fault memory
- On-board diagnosis II (OBD II)
- Diagnosis via the Controller Area Network (CAN)
- CAN network
- Flash programming
- Variant coding
- Drive authorization system stage 3 (DAS 3)
- Torque coordination
- Heat management
- Alternator interface
- Maximum vehicle speed limit
- Synchronization
- Load determination
Diagnosis
For diagnostic purposes, the fault codes from the engine control can be read off and deleted with Xentry Diagnostics, and specific diagnostic functions indicated.
CAN network
The CDI control unit exchanges data via the connected drive train CAN (CAN C) and chassis CAN (CAN E) with the other control units integrated in the CAN network.
The CDI control unit also acts as the interface (gateway) between the two CAN bus systems. The CDI control unit is also connected to the drivetrain LIN (LIN C1) and exchanges data over it.
Flash programming
The engine control in the CDI control unit is flash programmable, that is the complete software in the control unit can be exchanged (replaced) using Xentry Diagnostics. The software required for control unit programming can be found on the STAR DIAGNOSIS update DVD.
Variant coding
Using variant coding the following vehicle versions and equipment can be coded using Xentry Diagnostics:
- Vehicle model
- National version
- Exhaust variant
- Transmission version
Engine system
- Start relay actuation
- Throttle valve control
- Safety fuel shutoff
- Transmission overload protection
- Support for Electronic Stability Program (ESP)
- Support for fully integrated transmission control (VGS)
- Starting torque limitation
- Anti-jerk control
- Suction fan actuation
- Alternator regulation
- Glow time control
Injection system
- Pre, main and post injection
- Idle speed control
- Smooth running control
- Limp-home function
- Speed increase for air conditioning
- Inertia fuel shutoff
- Rail pressure regulation
- Fuel pump control
- High-pressure pump control
- Altitude adaptation
- Rpm limitation
Air control system
- Exhaust gas recirculation (EGR)
- Charge pressure control
- Intake air throttling through intake port shutoff (EKAS)
Exhaust system
- Catalytic converter heating
- Oxygen sensor heater control
- Exhaust after treatment, DPF regeneration (Diesel Particulate Filter) with code (474) Particulate filter
- Exhaust after treatment, injection of the reducing agent AdBlue(R) with code (U42) BlueTEC (SCR) diesel exhaust gas treatment
Engine 642.8 is characterized by the following components:
- V6 crankcase made out of aluminum instead of cast iron
- Balance shaft located in the "V" of both cylinder heads which turns in an opposite direction to the crankshaft
- Valve timing with roller-type cam followers
- Rapid glowing system with glow output stage (N14/3)
- A flow-dynamics optimized forced induction system consisting of a turbocharger with variable turbine geometry
- Exhaust gas recirculation with water-cooled exhaust gas recirculation cooler
- Highly efficient ventilation system with centrifugal oil separator
- Fuel injectors (Y76) with piezo technology
- Intake controlled high-pressure pump with lower than average operating energy input, which leads to reduced fuel consumption
Exhaust emission standards
Engine 642.8 complies with the EU-5 exhaust emission standards. 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.
The operating conditions of the engine and the concurrently active engine control subfunctions 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
^ On-board diagnosis, function
^ Engine control, start/stop function (with code (B03) ECO start/stop function)
^ Forced induction, function
^ Exhaust treatment, function
^ Exhaust gas recirculation, function
^ Preheat, function
