Ignition On, Function - GF07.10-D-1000TSA

Engine 651 in model 907 

Block diagram 

Function requirements for ignition ON, general points 

• Circuit 15 ON

Ignition ON, general points 

For ignition ON, the engine management in the CDI control unit is switched on and the engine is prepared for starting.

Function sequence for ignition ON 

When the ignition is switched on, the electronic ignition lock control unit (EZS) forwards the on-board electrical system voltage from "terminal 30" to "terminal 15".

If voltage is present at "circuit 15" on the CDI control unit, the relay at circuit 87M (F152kD) is activated with a ground signal.

This causes the relay to close its power contact and, according to the corresponding fuses, the "circuit 30" voltage is 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 "circuit 87", the engine management system is switched on and a output stage driver in the CDI control unit assumes responsibility for further actuation of the relay at terminal 87 engine.

The ground connection "circuit 31" is established by the on-board electrical system battery (G1) via the ground point for the front-right battery (W10).

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

• For complete security, the fuel pump with the fill level sensor is actuated via the fuel pump control unit (only the first time the ignition is switched ON after the vehicle is unlocked).
• In the instrument cluster, the engine diagnosis indicator lamp is actuated by the CDI control unit for monitoring.
• Data exchange with the electronic ignition lock control unit (EZS) (signal at circuit 50 and drive authorization).
• Actuation of the glow output stage. The glow output stage responds by actuating the glow plugs on the positive side. At the same time, the preglow indicator lamp (A1e16) in the instrument cluster is activated.
• The fault memory in the CDI control unit can be read out and deleted with XENTRY Diagnostics via the diagnostics connection.
• A diagnosis can be carried out with XENTRY Diagnostics via the diagnostics CAN and via diagnostics connection.
• The throttle valve actuator checks its return spring (via the position of the throttle valve) adjusts the position of the actuator as necessary.