Ignition On, Function - GF07.10-P-1000OLF

ENGINE 651.9 in MODEL 166 as of model year 2016 

Function requirements for ignition ON, general points 

• Circuit 30

Ignition ON, general points 

For ignition ON, the engine management in the CDI control unit (N3/9) is switched on and the engine prepared for starting.

Function sequence for ignition ON 

When the ignition is switched on, the electronic ignition lock control unit (N73) operating via the interior CAN (CAN B) and the SAM control unit (N10) switch on the circuit 15 relay (F58kR). The "circuit 15 ON" signal is sent redundantly via chassis CAN 1 (CAN E1) to the CDI control unit. The circuit 15 relay passes the on-board electrical system voltage from "circuit 30" onto "circuit 15".

If a voltage is present at the CDI control unit at "circuit 15", the engine circuit relay 87M (F58kN) is actuated by means of a ground signal.

This causes the relay to close its power contact and, according to the relevant fuses, the "circuit 30" voltage is forwarded as "circuit 87" to the CDI control unit and the relevant sensors and actuators of the engine management.

If a voltage is present at "circuit 87", the engine management is switched on and an output stage driver in the CDI control unit takes over further actuation of the circuit relay 87M.

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 engine management is switched on, the CDI control unit carries out the following functions:

• In order to prevent cylinder flooding, the fuel pump (M3) is actuated via drive train CAN (CAN C) and fuel system control unit (N118) (only the first time the ignition is switched ON after unlocking the vehicle)
• The engine diagnosis indicator lamp (A1e58) is actuated in the instrument cluster (A1) for a lamp check by the CDI control unit via chassis CAN 1 to the electronic ignition lock control unit and via chassis CAN 2 (CAN E2)
• Data is exchanged with the electronic ignition lock control unit (circuit 50 signal and drive authorization) via chassis CAN 1
• Actuation of the glow output stage (N143) over the drive train LIN (LIN C1). The glow output stage then responds by actuating the glow plugs (R9) on the positive side. The preglow indicator lamp (A1e16) is actuated via chassis CAN 1, electronic ignition lock control unit, chassis CAN 2 and the instrument cluster
• The fault memory in the CDI control unit can be read out and deleted via the diagnostic connector (X11/4)
• Diagnosis can be carried out using XENTRY Diagnostics via diagnostic CAN (CAN D) and the diagnostic connector
• The throttle valve actuator (M16/6) checks its return spring via the position of actual value potentiometer 1 (M16/6r1) and carries out actuator adaptation by actuating the actuator motor (M16/6m1) if necessary