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

ENGINE 642.8 in MODEL 166 up to model year 2016 

Function requirements for ignition OFF, general points 

• Circuit 87M (engine management ON)
• Terminal 15

Ignition OFF, general points 

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

Function sequence for ignition OFF 

With the ignition OFF, the circuit 15 relay (F58kR) is switched off by the electronic ignition lock control unit (N73) via interior CAN (CAN B) and the SAM control unit (N10).

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 (Y76)
• Quantity control valve (Y94)

For vehicles with code U42 (BlueTEC (SCR) diesel exhaust treatment), the AdBlue® control unit (N118/5) power-down is started. The remaining AdBlue® reduction agent is suctioned by the AdBlue® delivery pump (A103/2m1) out of the AdBlue® pressure line via the AdBlue® switchover valve (A103/2y1) actuated by the AdBlue® control unit during the control unit run-on. 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.

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".