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ELECTRONIC CONTROL SYSTEM
EOPS
ICP
MAP
Pressure Sensor Operation
• The Manifold Absolute Pressure
(MAP) sensor, the Injection Control
Pressure (ICP) sensor and the
Engine
Oil
Pressure
(EOPS) are used to send pressure
information to the ECM.
• The MAP and ICP are three-wire
pressure
sensors.
pressure
sensors
reference voltage and a ground
from the ECM. The sensor returns a
portion of the reference voltage,
proportional to the pressure, back
to the ECM as a signal.
Injection Control Pressure
(ICP) Sensor
• The ICP sensor is a Micro Strain
Gauge (MSG) style sensor. The
MSG type sensor has a small strain
gauge that senses changes in
pressure.
Sensor
electronic circuitry converts the
30
RIGHT BANK INJECTORS
LEFT BANK INJECTORS
X1-6 GRD
X1-13 EOPS
X1
X2
X1-14 V
REF
X3
X4
X1-20 ICP
X2-3 MAP
ECM
change into a signal voltage
proportional to the pressure being
measured. The ICP sensor is used
to make corrections to the IPR
signal and to continually check the
Switch
performance
Control Pressure system.
Manifold Absolute Pressure
(MAP) sensor
Three-wire
• The MAP sensor is a variable
receive
a
capacitance style sensor. In a
variable capacitance sensor, the
pressure being measured deflects a
ceramic disk towards a metal disk.
The two materials make up a
variable capacitor. Sensor mounted
circuitry converts the capacitance
into a signal voltage proportional to
the measured pressure. The MAP
sensor
boost in the intake manifold. The
MAP signal is input into calculations
that determine fueling quantities
mounted
and the desired EGR valve position.
International
EGR
DRIVE
MODULE
BCS
IPR
VALVE
of
the
Injection
measures
turbocharger
®
VT 275 V6 Engine
X1
X1
X2
X2
X3
X3
IDM
Functional Equivelant
VREF
SENSOR
MICRO-
PROCESSOR
REFERENCE
EGR
VOLTAGE
SWITCH
Engine Oil Pressure Switch
(EOPS)
• The EOPS is used to detect oil
pressure and is an input to the dash
cluster and the engine warning
protection system. The switch is
normally open with the engine off
but closes when oil pressure
reaches 5 to 7 psi. The ECM sends
5 volts through a current limiting
resistor to the EOPS and reads the
voltage between the resistor and
the switch. When oil pressure is
low, the switch is open and the
ECM reads 5 volts.
When the oil pressure is greater
than 5 to 7 psi, the switch is closed,
the circuit is shorted to ground, and
the ECM reads a low voltage.
When the ECM detects oil press-
ure, MasterDiagnostics
®
40 psi. When the oil pressure is
below 5 psi, MasterDiagnostics
will display 0 psi.
ECM
will display
®
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