Common Rail Diesel Injection (CDI), Function - GF07.16-D-0001TSC
Engine 642.8 in model 907
Sensors, actuators at CDI control unit (N3/28)
CAN cross-linking
Common rail direct injection CDI, general
The common rail direct injection (CDI) regulates an optimal injection quantity under all operating conditions. The engine management takes place through the CDI control unit.
The engine management is subdivided into the following systems:
- Engine system
- Diesel injection system
- Glow system control
- Fuel supply
- Injection quantity control
- Air control system
- Exhaust system
- Fuel high-pressure pump controller
- Altitude adaptation
- Rpm limitation
Glow system control
The CDI actuates the glow output stage via the CDI control unit. This in turn actuates the glow plugs (R9):
- Cylinder 1 glow plug (R9/1)
- Cylinder 2 glow plug (R9/2)
- Cylinder 3 glow plug (R9/3)
- Cylinder 4 glow plug (R9/4)
- Cylinder 5 glow plug (R9/5)
- Cylinder 6 glow plug (R9/6)
Engine system
- Throttle valve control
- Safety fuel shutoff
- Transmission overload protection
- Support of the Electronic Stability Program (ESP®)
- Anti-jerk control
- Glow time control
- European On-Board Diagnosis (EOBD)
- Variant coding
- Torque coordination
- Alternator interface
- Load determination
- Maximum vehicle speed limit
Diesel injection system
- Pre, main and post injection
- Idle speed control
- Smooth running control
- Limp-home function
- A/C RPM increase
- Inertia fuel shutoff
- Rail pressure regulation
- Fuel pump controlling
One differentiates between preglowing, start-up glowing and afterglowing.
Fuel supply
The fuel system control unit (N118/9) actuates the fuel pump with the fill level sensor (M3/6), which supplies fuel to the high-pressure pump via the fuel filter. Depending on actuation by the CDI control unit, the quantity control valve (Y94/4) regulates the feed to the high-pressure pump to about 4.0 bar.
Injection quantity control
The high-pressure pump pushes the fuel with an increased pressure in the common rail which distributes the fuel to the fuel injectors (Y76). The CDI control unit actuates the fuel injectors, rotational speed and load-dependent:
- Cylinder 1 injector (Y76/18)
- Cylinder 2 injector (Y76/19)
- Cylinder 3 injector (Y76/20)
- Cylinder 4 injector (Y76/21)
- Cylinder 5 injector (Y76/22)
- Cylinder 6 injector (Y76/23)
Differentiation is made between preinjection, main injection and post-injection. The system's maximum injection pressure is 1600 bar.
Air control system
- Charge pressure control
- Exhaust gas recirculation (EGR)
- Intake air throttling through intake port shutoff (EKAS)
Exhaust system
- Catalytic converter heating
- Oxygen sensor heater
- Exhaust treatment, diesel particulate filter (DPF) regeneration
- Exhaust aftertreatment, injection of the reduction agent AdBlue®
| Ignition ON, function | GF07.10-D-1000TSC | |
| Starting, function | GF07.10-D-1001TSC | |
| Ignition OFF, function | GF07.10-D-1002TSC | |
| Fuel supply, function | GF07.10-D-1003TSC | |
| Injection regulation, function | GF07.10-D-1004TSC | |
| RPM control, function | GF07.10-D-1008TSC | |
| Alternator interface function | GF07.10-D-1009TSC | |
| Smooth running control, function | GF07.10-D-1011TSC | |
| Thermal management, function | GF07.10-D-1012TSC | |
| Torque coordination, function | GF07.10-D-1013TSC | |
| Overrun mode fuel shutoff, function | GF07.10-D-1014TSC | |
| Engine limp-home mode, function | GF07.10-D-1019TSC | |
| European OBD, function | GF07.10-D-1021TSC | |
| ECO start/stop function engine management, function | With CODE MJ8 (ECO start/stop function) | GF07.10-D-1042TSC |
| Charging, function | GF09.00-D-2000TSC | |
| Exhaust gas recirculation, function | GF14.20-D-3000TSC | |
| Preheat, function | GF15.20-D-3005TSC | |
| Exhaust gas cleaning, function | GF49.20-D-3000TSC | |
| Overview of system components for common rail diesel injection (CDI) | GF07.16-D-9997TSC |