User Manual

SENR9977 29
Systems Operation Section
i02285310
Glossary of Electronic Control
Terms
Aftermarket D
evice – An aftermarket device i s
a device or an accessory that is installed by the
customer after the engine is delivered.
Air-To-Air Aftercooler – An air-to-air aftercooler is a
device that is used on turbocharged engines in order
to cool inlet
air that has undergone compression. The
inlet air is cooled after the inlet air passes through
the turbocharger. The inlet air is passed through an
aftercooler
(heat exchanger) that uses ambient air for
cooling. The inlet air that has been cooled advances
to the inlet manifold.
Before Top Center (BTC) – BTC is the 180 degrees
of crankshaft rotation before the piston reaches the
top center p
osition in the normal direction of rotation.
Bypass Circuit – A bypass circuit is a circuit that is
used as a sub
stitute circuit for an existing circuit. A
bypass circuit is typically used as a test circuit.
Coolant Tem
perature Sensor – The coolant
temperature sensor measures the engine coolant
temperature. The sensor sends a signal to the ECM.
The engine
’s coolant temperature is used in Cold
Mode operation. Coolant temperature is also used in
order to optimize engine performance.
Code – See the Diagnostic Code.
Customer
Specified Parameters – Acustomer
specified parameter is a parameter that can be
changed. A customer specified parameter’s value is
set b y t he
customer. These parameters are protected
by customer passwords.
Data Link
– The data link is an electrical connection
that is used to communicate with other electronic
devices that have microprocessors. The data link
is also t
he communication medium that is used for
programming with the electronic service tool. The
data link is also used for troubleshooting with the
electro
nic service tool.
Desired RPM – The desired rpm is input to the
electr
onic governor within the ECM. The electronic
governor uses the signal from the Accelerator Pedal
Position Sensor, the Engine Speed Sensor, the
Cruise
Control, and the Customer Parameters in
order to determine desired rpm.
Diagno
stic Code – A diagnostic code is sometimes
called a fault code. A diagnostic code is an indication
of a problem or event in the electrical engine systems.
Diagnostic Lamp – A diagnostic lamp is sometimes
called the chec
k engine light. The diagnostic lamp
is used to warn the operator of the presence of an
active diagnostic code.
Direct Current (DC) – Direct current is the type of
current that flows consistently in only one direction.
Duty Cycle – See Pulse Width Modulation.
Electronic Se
rvice Tool – The Electronic Service
Tool is used for diagnosing a variety of electronic
controls and the Electronic Service Tool is also used
for programm
ing a variety of electronic controls.
Engine Control Module (ECM) – The ECM is the
engine’s con
trol computer. The ECM provides power
to the electronics. The ECM monitors data that is
input from the engine’s sensors. The ECM acts as a
governor in
order to control engine rpm.
Estimated Dyna m ic Timing – Estimated dynamic
timing is th
e estimate of the actual injection timing
that is calculated by the ECM.
Enable Sign
al for the Exhaust Brake – Th e
exhaust brake enable signal interfaces the ECM to
the engine retarder. This prevents the operation of
the exhaus
t brake under unsafe engine operating
conditions.
Failure Mo
de Identifier (FMI) – The FMI describes
the type of failure that was experienced by the
component. The codes for the FMI were adopted from
the standa
rd practices of SAE (J1587 diagnostics).
Flash Memory – See the Personality Module.
Fuel Ra tio Control (FRC) – The FRC is a limit that
is based on the control of the fuel to the air ratio. The
FRC is use
d for emission control. When the ECM
senses a higher turbocharger outlet pressure, the
ECM increases the limit for the FRC in order to allow
more fue
l into the cylinders.
Fuel Position – The fuel position is a signal within
the ECM.
The signal is from the electronic governor.
The signal goes to the fuel injection control. The
signal is based on the desired engine speed, the
FRC, the
rated position, and the actual engine speed.
Harness – The harness is the bundle o f wiring that
connec
ts all the components of the electrical engine
system.
Hertz (
Hz) – Hz is the measure of frequency in
cycles per second.
Intake
manifold temperature sensor – The
intake manifold temperature sensor is a sensor that
measures the intake air temperature. The sensor
also se
nds a signal to the ECM.