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Ignition OFF, function - GF07.10-P-1002OGG

ENGINES 642.8 in MODEL 164.1 as of model year 2009/YoM 08 model refinement package 

ENGINES 642.8 in MODEL 164.8, 251.1 as of model year 2009/YoM 08 

ENGINES 642.8 in MODEL 251.0/1 as of model year 2011/Yom 10 model refinement package 

Function requirements for ignition OFF, general points 

Ignition OFF, general points 

When the ignition is switched off, first the engine and then the CDI engine control unit (N3/9) are switched off.

Function sequence for ignition OFF 

With ignition OFF the EZS (EIS) control unit (N73) switches off relay circuit 15 (F58kH) on the front SAM control unit (N10) via the CAN engine compartment (CAN C).

If the CDI control unit receives the signal "circuit 15 OFF" via the circuit 15 relay, the following components are switched off and the computer run-on is started:

IMPORTANT For vehicles with code (U42) BlueTEC (SCR) diesel exhaust treatment, the run-on period of the AdBlue® control unit (N118/5) is started. The remaining AdBlue® reducing agent is suctioned by the AdBlue® delivery pump (A103/2m1) out of the AdBlue® pressure line via the AdBlue® reversing valve (A103/2y1) actuated by the AdBlue® control unit during the control unit power down. The AdBlue® metering valve (Y129) is opened at the same time so that no vacuum arises in the AdBlue® pressure line. The duration of power-down and the point in time of reducing agent return are dependent on the exhaust temperature which is 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 period is determined by the CDI control unit and lasts about 4 s. It can, however, last for several minutes due to various functions (such as On-board Diagnosis (OBD), Drive Authorization System (DAS), thermal management).

Once the computer power-down has ended, the terminal relay 87 for the engine (F58kD) is switched off and thus the engine control is separated from the on-board electrical system (switched off).

IMPORTANT System tests are conducted by the CDI control unit during the computer run-on period and the fault memory is updated.

The "circuit 31" ground connection runs from the battery (G1) through battery ground (W10) and several ground lines to the ground of the RH major assemblies compartment (power ground (W16/4)). When the ignition is OFF, the CDI control unit is supplied with power from the battery through "circuit. 30 fused".

REFER TO SYSTEM WIRING DIAGRAMS Electrical function diagram for ignition OFF Model 164 PE07.10-P-2702-97MAA
Model 251 PE07.10-P-2702-97RAA
  Component description for CDI control unit N3/9 GF07.16-P-6000OGU 
  Component description for front SAM control unit N10 GF54.21-P-7010GM
  Component description for EZS (EIS) control unit N73 GF80.57-P-6003GM
  Component description for AdBlue control unit N118/5 With code (U42) BlueTEC (SCR) diesel exhaust treatment GF14.40-P-3030OGU
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