Engine Management System; System Description; System Sensors - Triumph Rocket III Classic Service Manual

Fuel System/Engine Management
Engine Management System
System Description
The Rocket Ill, Rocket III Classic and Rocket III Touring are
fitted with an electronic engine management system
which encompasses control of both ignition and fuel
delivery. The electronic control module (ECM) draws
information from sensors positioned around the engine,
cooling and air intake systems and precisely calculates
ignition advance and fueling requirements for all engine
speeds and loads.
In addition, the system has an on-board diagnostic
function. For additional information, see page 1/-28.
System Sensors
Intake air temperature sensor - situated at
the front of the intake duct, above the camshaft
cover. As the density of the air changes with
temperature (therefore the amount of oxygen
available to ignite the fuel), an intake air
temperature sensor is fitted. Changes in air
temperature are compensated for by adjusting
the amount of fuel injected to a level consistent
with clean combustion and low emissions.
Barometric pressure sensor - situated
beneath the motorcycle seat, in the top of the
airbox. The barometric pressure sensor
measures atmospheric air pressure. With this
information, the amount of fuel per injection is
adjusted to suit the prevailing conditions.
Manifold Absolute Pressure <MAP) sensor
- situated at the front of the intake duct, above
the camshaft cover, connected to each of the
three throttle bodies by equal length tubes. The
MAP sensor provides information to the ECM
which is used at shallow throttle angles (very
small throttle openings) to provide accurate
engine load indications to the ECM. This
degree of engine load accuracy allows the ECM
to make very small adjustments to fuel and
ignition which would otherwise not be possible
from throttle angle data alone.
• Clutch switch - situated on the clutch lever.
The clutch must be pulled in for the starter
motor to operate.
Crankshaft position sensor - situated in the
alternator cover. The crankshaft position sensor
detects movement of a toothed wheel attached
to the alternator rotor.
The toothed wheel gives a reference point from
which the actual crankshaft position is
calculated. The crankshaft position sensor
information is used by the ECM to determine
engine speed and crankshaft position in relation
to the point where fuel is injected and ignition
of the fuel occurs.
Engine coolant temperature sensor -
situated towards the front of the cylinder head,
on the left hand side. Coolant temperature
information, received by the ECM, is used to
epitomise fueling at all engine temperatures
and to calculate hot and cold start fueling
requirements.
Primary throttle position sensor - situated at
the rear of the lower throttle spindle. Used to
relay throttle position information to the ECM.
Throttle opening angle is used by the ECM to
determine fueling and ignition requirements for
all throttle positions.
Secondary throttle position sensor -
situated at the front of the upper throttle
spindle. Used to relay secondary throttle
position information to the ECM. Secondary
throttle angle is used by the ECM to determine
secondary throttle opening position under all
engine running conditions.
Road speed sensor - situated in the lower
crankcase, on the left hand side. The road
speed sensor provides the ECM with data from
which road speed is calculated and displayed
on the speedometer. A vehicle speed limitation
device also receives information from the road
speed sensor.
Lambda sensor - situated in the exhaust
header system upstream of the catalyst box.
The lambda sensor constantly feeds
information to the ECM on the content of the
exhaust gases. Based on this information,
adjustments to air/fuel ratio are made.
Side stand switch - situated at the top of the
sidestand leg.
If
the sidestand is in the down
position, the engine will not run unless the
transmission is in neutral.
Fall detection switch - situated behind the left
hand side cover. The fall detection switch will
detect if the motorcycle is on its side and will
cut power to the ECM immediately. This
prevents the engine from running and the fuel
pump from delivering fuel. In the event of a fall,
the switch is reset by returning the bike to an
upright position and switching the ignition off
then back on again.
11.20
Service Manual - Rocket III / Classic / Touring
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