8 KENR6933
Troubleshooting Section
Derate – Certain engine conditions will generate
event codes. Al
so, engine derates may be applied.
The map for the engine derate is programmed into
the ECM software. The derate can be one or more of
3 types: reduc
tion of rated power, reduction of rated
engine speed, and reduction of rated machine speed
for OEM products.
Desired E ngine Speed – The desired engine speed
is input to the electronic governor within the ECM.
The electron
ic governor uses the signal from the
throttle position sensor, the engine speed/timing
sensor, and other sensors in order to determine the
desired eng
ine speed.
Diagnostic Code – A diagnostic code is sometimes
referred to
as a fault code. These codes indicate an
electronic system malfunction.
Diagnostic
Lamp – A diagnostic lamp is sometimes
called the check engine light. The diagnostic lamp
is used to warn the operator of the presence of
an active d
iagnostic code. The lamp may not be
included in all applications.
Digital Se
nsor Return – The common line (ground)
from the ECM is used as ground for the digital
sensors.
Digital Sensors – Digital sensors produce a pulse
width modulated signal. Digital sensors are supplied
with powe
rfromtheECM.
Digital Sensor Supply – The power supply for the
digital s
ensors is provided by the ECM.
Direct Current (DC) – Direct current is the type of
current t
hat fl ows consistently in only one direction.
DT, DT Connector, or Deutsch DT – This is a type
of connec
tor that is used on Perkins engines. The
connectors are manufactured by Deutsch.
Duty Cyc
le – Refer to “Pulse Width Modulation”.
Electronic Engine Control – The electronic
engine c
ontrol is a complete electronic system.
The electronic engine control monitors the engine
operation under all conditions. The electronic engine
control
also controls the engine operation under all
conditions.
Electr
onic Control Module (ECM) – The ECM
is the control computer of the engine. The ECM
provides power to the electronics. The ECM monitors
data th
at is input from the sensors of the engine. The
ECM acts as a governor in order to control the speed
and the power of the engine.
Electronic Service Tool – The electronic service
tool allows a co
mputer (PC) to communicate with the
ECM.
Engine Monito
ring – Engine Monitoring is the part
of the electronic engine control that monitors the
sensors. This also warns the operator of detected
problems.
Engine Oil Pressure Sensor – The engine oil
pressure sen
sor measures engine oil pressure. The
sensor sends a signal to the ECM that is dependent
on the engine oil pressure.
Engine Speed/Ti ming Sensor – An engine
speed/timing sensor is a hall effect switch that
provides a di
gital signal to the ECM. The ECM
interprets this signal as the crankshaft position and
the engine speed. Two sensors are used to provide
the speed an
dtimingsignalstotheECM.Theprimary
sensor is associated with the crankshaft and the
secondary sensor is associated with the camshaft.
Event Code – An event code may be activated
in order to indicate an abnormal engine operating
condition
. These codes usually indicate a mechanical
problem instead of an electrical system problem.
Failure Mo
de Identifier (FMI) – This identifier
indicates the type of failure that is associated with
the component. The FMI has been adopted from the
SAE pract
ice of J1587 diagnostics. The FMI follows
the parameter identifier (PID) in the descriptions of
the fault code. The descriptions of the FMIs are in
the follo
wing list.
0–The data is valid but the data is above the normal
operati
onal range.
1–The data is valid but the data is below the normal
operati
onal range.
2–The data is erratic, intermittent, or incorrect.
3–The voltage is above normal or the voltage is
shorted high.
4–The voltage is below normal or the voltage is
shorted low.
5–The current is below normal or the circuit is open.
6–The cu
rrent is above normal or the circuit is
grounded.
7–The me
chanical system is not responding
properly.
8–There
is an abnormal frequency, an abnormal
pulse width, or an abnormal time period.
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