New Generation N62 Engine
Chapter 4 P.22
Course Contents/Background Material
© BMW AG,
Service Training
Once the target value has been reached, the engine is
controlled contrary to the exact positioning. This measure tests
the engine. The Valvetronic control unit transmits the exact
position of the eccentric shaft to the DME control unit via the
LoCAN bus.
If the Valvetronic control unit detects a peripheral fault, it
transmits this to the DME too. The DME then stores it in the fixed
fault memory.
Emergency running lead
There is another interface between the DME control unit and the
Valvetronic control unit which is known as the emergency
running wire. It is operated by the DME control unit and the
Valvetronic control unit. Only two messages can be transmitted
using this wire:
- Test function
- Maximum valve lift
A signal with a frequency of 100 Hz is placed on this wire to
transmit these two messages.
Fault
Emergency
programme
Effect
Sensor faulty
Activated
Maximum valve lift
LoCAN bus faulty
Activated
Maximum valve lift
Valvetronic
control unit faulty
Activated
Valve lift which is currently
set
Operating motor
faulty
Activated
A second motor is driven in
exactly the same position as
the faulty motor