Ignition Off, Function - GF07.10-P-1002OGF

ENGINE 642.8 in MODEL 166

as of model year 2016

ENGINE 642.8 in MODEL 292

Function requirements for ignition OFF, general points

Circuit 87M (engine management ON)
Terminal 15

Ignition OFF, general points

With ignition OFF, first the engine and then the engine management are switched off in the CDI control unit (N3/9).

Function sequence for ignition OFF

When the ignition is switched off, the electronic ignition lock control unit (N73) switches off the circuit 15 relay (F58kR) via the interior CAN (CAN B).

If the CDI control unit receives the "Circuit 15 OFF" signal over circuit 15 relay, the following components will be switched off and the processor power-down is started:

The fuel pump (M3) via the drive train CAN (CAN C) and FSCU (N118)
Pressure regulating valve (Y74)
Fuel injectors for cylinders 1 to 6 (Y76/1 to Y76/6)
Quantity control valve (Y94)

Control unit after-run in vehicles with code U77 (BlueTEC (SCR) Diesel exhaust treatment)

During the control unit after-run, the remaining AdBlue® reduction agent is sucked out of the AdBlue® pressure line by the AdBlue® delivery pump (A103/2m1) via the AdBlue® extraction pump (A103/2m2), which is actuated by the AdBlue® control unit (N118/5). The AdBlue® metering valve (Y129) is opened at the same time so that no vacuum arises in the AdBlue® pressure line. The duration of the run-on and the timing of the reduction agent return are dependent on the exhaust temperature as detected by the temperature sensor upstream of the SCR catalytic converter (B16/15) since excessively hot exhaust can damage the AdBlue® pressure line and other system components. The computer run-on for the AdBlue® control unit is determined by the CDI control unit, via the drive train sensor CAN (CAN I), and is for approx. 4 s. However, it may also last for several minutes due to various functions (for example, on-board diagnosis (OBD), drive authorization system (DAs), thermal management).

Information for partial function "no-load current shutoff" is documented in the function description "Engine OFF energy management function".

When the computer run-on is complete, the circuit relay 87M (F58kN) is switched off and the engine management is disconnected from the on-board electrical system (switched off).

Ground connection "circuit 31" takes place by the on-board electrical system battery (G1) over the on-board electrical system battery ground point at the front right (W10) and over a number of ground lines to the ground point on the front right for the lamp unit (W2).

When the ignition is OFF, the CDI control unit is supplied with power from the on-board electrical system battery via "circuit 30 fused".

	Electrical function schematic for ignition OFF		PE07.10-P-2702-97NBD
	Overview of system components for common rail diesel injection (CDI)		GF07.16-P-9997OGF