X Series E70 X5 4.8i (N62TU) OFFRD
At the same time, the CAS control unit sends the DME control unit an encoded release signal (alternating code)
to start the engine. The DME control unit only enables the start if a correct release signal has been received
from the CAS control unit.
These operations may result in a slight delay in starting (up to half a second).
The following faults are stored in the DME control unit:
•
Missing or disturbed release signal from the EWS control unit
•
Alternating code from the CAS control unit does not tally with the alternating code computed by the DME
control unit.
If a fault is detected, the engine start is blocked.
Convenient-start system
The convenient-start system allows the engine to be started in a user-friendly manner as the starter motor
automatically remains engaged until the engine is running.
When the START-STOP button is pressed, the CAS control unit first activates terminal 15. The relief relay for
the ignition coils is activated.
When the START-STOP button is pressed, the CAS control unit checks that the brake pedal is depressed and
the selector lever is in P or N.
The engine start process runs as follows:
•
First, the EWS is checked via the EWS data wire.
•
If the data is correct, the DME enables the ignition and the fuel injection.
•
The CAS control unit switches battery voltage to the DME control unit via terminal 50E. This gives the signal
for the required engine start.
•
The CAS control unit switches battery voltage to the starter motor via terminal 50L. The starter motor is
switched on by the DME via the starter inhibitor relay.
> E65, E66 and E70
The DME switches the starter motor on.
•
The starter motor continues to turn until the CAS control unit receives the "engine running" signal from the
DME through the data bus. The terminals 50 are then switched off by the CAS control unit.
If the engine does not start, the terminals 50L and 50E will be switched off after a maximum of
20 seconds. The engine start is thus aborted.
Air supply: 2-stage differentiated air intake system "DISA"
The intake strokes of the pistons generate cyclic pressure waves in the inlet pipe.
These pressure waves travel along the inlet pipe and are reflected by the closed inlet valves.
A precise matching of the inlet pipe length with the valve response time produces the following effect:
Shortly before the inlet valve is closed, a pressure maximum of the reflected air wave reaches the inlet valve.
This has a supercharging effect which pumps a higher proportion of fresh air into the cylinder.
The differentiated air intake system also makes use of the inherent benefits of both short and long inlet pipes.
•
The effect of short inlet pipes or inlet pipes with a large diameter is a high efficiency in the upper engine
speed range (and also low torque in the medium engine speed range).
•
Long inlet pipes or inlet pipes with a small diameter make high torque in the medium engine speed range
possible.
A front intake pipe is installed upstream of each resonating pipe. When the sliding sleeves are closed, the
combined effect of the front intake pipe and resonating pipe is similar to that of a long inlet pipe.
SBT 8-cylinder spark-ignition engine N62TU E60, E61, E63, E64, E65, E66, E70
BMW AG - TIS
09.02.2013 00:27
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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