S07.10-0028-79
Block diagram |
B2/8 | Hot film mass air flow sensor | N118 | Fuel system control unit (FSCU) | |
B11/17 | Coolant temperature sensor | Y76 | Fuel injectors | |
B37/4 | Accelerator pedal module | Y94/3 | Quantity control valve | |
B70/2 | Crankshaft Hall sensor | CAN V | Vehicle CAN | |
M3/3 | Fuel pump with fuel feed module | A | Mercedes-Benz | |
N3/33 | CDI control unit | B | Nissan | |
N30/4 | Electronic Stability Program (ESP) control unit | C | Default | |
N50 | Fuse and relay module control unit (SRM) | D | Optional | |
N93 | Central gateway (CGW) |
Function requirements for smooth running control, general points
Engine running.
Smooth running control, general points
The smooth running control reduces rough running of the engine.
For smooth running control, the CDI control unit (N3/33) reads in the following sensors and signals among others:
Hot film mass air flow sensor (B2/8)
Coolant temperature sensor (B11/17)
Accelerator pedal module (B37/4)
Crankshaft Hall sensor (B70/2)
Wheel speed signal from Electronic Stability Program (ESP) control unit (N30/4)
Function sequence for smooth running control
The function sequence is described in the following steps:
Function sequence for combustion misfire detection
Factors for smooth running control
Function sequence for combustion misfire detection
In order to recognize combustion misfires, the CDI control unit (N3/33) evaluates the signal of the crankshaft Hall sensor (B70/2) for its uniformity.
If lack of uniformity occurs on a signal of the crankshaft Hall sensor (B70/2), the CDI control unit (N3/33) corrects the fuel quantity in the rail over the quantity control valve (Y94/3) and the injection period via actuation of the fuel injectors (Y76).
The fuel pressure in the rail and the actuation time of the fuel injectors (Y76) produces the injection quantity.
Factors for smooth running control
The following factors affect smooth running control:
Recognition of road bumps
Fuel reserve signal
Sensor adaptation
Recognition of road bumps
Vibrations transmitted through the drivetrain may have a negative effect on evaluation of the engine running at certain engine speeds and load conditions. Therefore, the tolerance range for smooth running control is increased on poor road surfaces.
The wheel speed signal (for recognition of an even wheel arch) is received by the CDI control unit (N3/33), over the Electronic Stability Program (ESP) control unit (N30/4).
Fuel reserve signal
The fuel system control unit (FSCU) (N118) analyzes the signals from the fuel pump with fuel feed module (M3/3).
Sensor adaptation
The tolerance range for smooth running control is reduced after successful adaptation of the crankshaft Hall sensor signal (B70/2). In this way, the smooth running control can be adapted to the specific smooth running characteristics of the engine.
In decel mode (accelerator pedal not pressed), at which uniform smooth operation is given, the CDI control unit (N3/33) stores the engine's smooth running properties. These are required as a comparison parameter for misfire detection.
The tolerance range for smooth running control is preset in the CDI control unit (N3/33) and can be adapted if necessary.