S07.10-0059-79
Block diagram |
A1/1 | Instrument cluster (KI) control unit | X11 | Diagnostic connector | |
A1/1e16 | Preglow indicator lamp | CAN C | Drive train CAN | |
A1/1e58 | Engine diagnosis indicator lamp | CAN D | Diagnostic CAN | |
M3/3 | Fuel pump with fill level sensor | CAN E | Chassis CAN | |
M16/6 | Throttle valve actuator | CAN HMI | User interface CAN | |
N3/28 | CDI control unit | CAN V | Vehicle CAN | |
N14/8 | Glow output stage | LIN C3 | Drivetrain LIN | |
N50 | Fuse and relay module control unit (SRM) | A | Mercedes-Benz | |
N93 | Central gateway (CGW) | B | Nissan | |
N118 | Fuel system control unit (FSCU) | C | Default | |
R9 | Glow plugs | D | Optional | |
S2 | Ignition lock switch |
Function requirements for ignition ON, general points
Chassis 30
Ignition ON, general points
With ignition ON, the engine management in the CDI control unit (N3/28) is switched on and the engine prepared for starting.
Function sequence for ignition ON
When the ignition is switched on, the ignition lock switch (S2) forwards the on-board electrical system voltage from circuit 30 to circuit 15 via the fuse and relay module (SRM) control unit (N50) and via relay circuit 15. The "circuit 15 ON" signal is sent redundantly from the fuse and relay module (SRM) control unit to the CDI control unit. If a voltage is present on the CDI control unit at "circuit 15", the engine supply relay is actuated with a ground signal. This causes the relay to close its power contact and, according to the corresponding electrical fuses, the voltage from circuit 30 passed on as circuit 87 to the CDI control unit and to the corresponding sensors and actuators of the engine management.
If voltage is present at circuit 87, the engine management switches on and an output stage driver takes over further actuation of the engine supply relay in the CDI control unit. The circuit 31 ground connection takes place from the on-board electrical system battery (G1).
When the engine management is switched on, the CDI control unit carries out the following functions:
For protection against flooding cylinders, the fuel pump as actuated with the fill level sensor (M3/3) by the CDI control unit via the fuel pump relay (only the first time ignition ON is set after the vehicle is unlocked)
In the instrument cluster (IC) control unit (A1/1) is actuated by the CDI control unit (A1/1e58) to check the engine diagnosis indicator lamp.
Actuation of the glow output stage (N148) over the drivetrain LIN (LIN C3). The glow output stage then actuates the glow plugs (R9) on the positive side and the preglow indicator lamp (A1/1e16) is actuated in the instrument cluster (IC) control unit.
The fault memory in the CDI control unit can be read out and deleted with XENTRY Diagnostics via the diagnostics connection (X11).
The throttle valve actuator (M16/6) checks its return spring (via the position of the throttle valve) and adjusts the position of the actuator, if necessary.