CDI driving mode, function

GF07.16-D-2003HOA

CDI driving mode, function

18.6.13

ENGINE

642.992 in MODEL 906.111/113/131/133/135/153/155/211/213/231/233/235/253/255/611/613/631/633/635/637/653/655/657/711/713/731/733/735

Function requirements, general

 "Circuit 61 ON"

 Vehicle rolling

Driving mode common rail direct injection (CDI), general points

The basic tasks of the CDI in automotive operation include providing an engine torque which matches the driver's requirements. At the same time, the CDI should provide for best smooth running characteristics at the lowest possible fuel consumption and minimal exhaust emissions. To do this, the CDI control unit (N3/20) must adjust the CDI as well as the air and exhaust system to one another according to the stored performance map data.

For this purpose, the CDI control unit evaluates the following sensor information:

– hot film MAF sensor (B2/7), suction in air mass

– rail pressure sensor (B4/6)

– boost pressure sensor (B5/1)

– coolant temperature sensor (B11)

– charge air temperature sensor (B17/9)

– intake manifold pressure sensor (B28), for the vacuum in intake manifold

– accelerator pedal module (B37/3), for the driver's request

– fuel temperature sensor (B50), fuel temperature

- crankshaft sensor (L5), for the engine rpm

– oxygen sensor (B85/2), for the residual oxygen content in exhaust

- diesel particulate filter differential pressure sensor (B28/8), for the load condition of the diesel particulate filter (DPF)

– catalytic converter temperature sensor (B19)

– temperature sensor upstream of diesel particulate filter (B19/12)

– temperature sensor upstream of turbocharger (B16/11)

The CDI control unit is connected to the following control units via the drive LIN (LIN-C1):

– alternator with LIN bus (G2/7)

- glow output stage (N143), glow function control

The CDI control unit also communicates with the following control units via the engine compartment CAN (CAN-C), to obtain the related variables:

– with the instrument cluster (A1), vehicle speed

– with the Electronic Stability Program control unit (N30/4), for example torque request from the Electronic Stability Program (ESP®), wheel speeds

– with the EZS control unit (N73), interface to the interior CAN (CAN B), for example the switch condition of the A/C (with code (HH9) Regulated air conditioning, (Tempmatic))

– with the EGS control unit (N15/3) (vehicles with gearing 722.6), gear range

When driving, the following function sequences are active; they are described in separate documents:

 CDI fuel supply

 CDI injection control

 CDI quantity control

 CDI decel mode

 CDI zero quantity calibration

 CDI engine torque request

 CDI quantity mean value adaptation

 CDI alternator interface

 CDI thermal management

 Charging

 Exhaust treatment

 Exhaust gas recirculation

 CDI preheating

 The engine speed is governed to approx. 4500 rpm. This serves to prevent mechanical damage to the engine caused by overrevving. From an engine speed of about 4500 rpm the CDI control unit interrupts actuation of cylinder 1 injector (Y76/1), cylinder 2 injector (Y76/2), cylinder 3 injector (Y76/3), cylinder 4 injector (Y76/4), cylinder 5 injector (Y76/5) and cylinder 6 injector (Y76/6) and lowers the fuel pressure in the rail over the quantity control valve (Y94) and the pressure regulating valve (Y74/1).

	CDI fuel supply, function		GF07.16-D-2006HOA
	CDI injection control function		GF07.16-D-2014HOA
	CDI quantity control, function		GF07.16-D-3004HOA
	CDI overrun mode, function		GF07.16-D-3008HOA
	CDI zero quantity calibration function		GF07.16-D-3009HOA
	Engine torque request, CDI function		GF07.16-D-3014HOA
	CDI quantity mean value adaptation function		GF07.16-D-3020HOA
	CDI alternator interface, function		GF07.16-D-3022HOA
	CDI thermal management, function		GF07.16-D-3023HOA
	Charging, function		GF09.00-D-2000HO
	Exhaust treatment function		GF14.00-D-3000HOA
	Exhaust gas recirculation, function		GF14.20-D-3000HOA
	CDI glow function		GF15.20-D-3004HOA