Porsche 911 - Manual (Page 24)

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Engine management system.
The EMS SDI 3.1 engine manage-
ment system ensures optimum
engine performance at all times.
In particular, it controls the
position of the electronic throttle
valve (ETC) – a prerequisite
for compatibility with the Porsche
Stability Management (PSM), which
comes as standard. Moreover,
it regulates all engine-related
functions and assemblies (see
diagram). The results: optimum
fuel economy, emissions, and
performance in all driving situations.
Another important function of the
system is cylinder-specific knock
control. Since the six cylinders
never all work under exactly
the same conditions, they are
monitored individually by the
knock control. The ignition point
is shifted individually, as and
when necessary. This prevents
damage to a cylinder or piston at
high engine speeds and loads.
The on-board diagnostics, which
Input data Regulation/control of
Electroni
c
Engine
Management
EMS
SDI
3.1
Engine load
Lambda sensor signals
Knock sensor signals
Engine speed (from crankshaft)
Inlet camshaft phase angle
Vehicle speed
Air-conditioning settings
Accelerator pedal
Temperatures – Coolant
– Intake air
– Engine oil
– Air in engine
compartment
– Ambient air
Ignition
Direct fuel injection
Heating of lambda sensors
Fuel pumps controlled on-demand
Fuel-tank venting
CAN interface with driving dynamics control, transmission control, immobiliser,
instrument cluster, climate control, Sport button, Sport Plus button, sports exhaust system button, diagnostics, etc.
Engine fan
Starter
Oil pressure
Fuel pressure
Throttle valve
Throttle-valve angle
Idling via throttle valve and ignition
Camshaft position
Valve lift switchover
(VarioCam Plus)
Pressures – Engine oil
– Fuel
– Ambient air
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The new 911 | Engine
911 Targa 4S
are compliant with European
standards, ensure timely detection
of any faults and defects that
may occur in the exhaust and fuel
systems and notify the driver
immediately. This also prevents
increased pollutant emissions and
unnecessary fuel consumption.
Servicing.
Every Porsche is designed with
longevity in mind and the new
911 is no different. The alternator,
power-steering pump and the
air-conditioning compressor
are all driven by a single self-
adjusting belt. Hydraulic valve
clearance compensation makes
valve clearance adjustment
unnecessary. The drive chains on
the camshafts do not require
servicing. With the sole exception
of the spark plugs, the ignition
system is also maintenance-free.
This all adds up to long
maintenance intervals which are
guaranteed by warranty: two
years, unlimited mileage.