New Generation N62 Engine Chapter 4 P.21
Course Contents/Background Material
© BMW AG, Service Training
- Function
The electrical structure of the fully variable valve lift adjustment
consists of the following individual components:
- Valvetronic control unit
- DME control unit
- DME main relay
- Valvetronic additional relay
- Two eccentric shaft adjustment motors
- Two eccentric shaft position sensors
- Two magnetic wheels on the eccentric shafts
Activation of terminal 15 switches the DME main relay and also
supplies voltage to the Valvetronic control unit.
Modules inside the control unit reduce the voltage supply to the
control unit electronics system and the sensors to 5 volts.
The electronics system carries out a pre-drive check. The
additional relay electronics are switched on after a delay
(approx. 100 ms), which guarantees the load current circuit. The
delayed connection protects the relay contacts from charring.
From this stage on, the DME control unit and the Valvetronic
control unit communicate via the LoCAN bus. The DME deter-
mines with which valve lift the charge cycle will be carried out, in
accordance with the load required by the driver.
The Valvetronic control unit converts the DME command by
operating the operating motor at 16 kHz until the actual value
from the eccentric shaft position sensor corresponds with the
target value.
To Next Page
Loading...
Need help?
General
