146 KENR9126
Troubleshooting Section
i04010989
Engine Pressure Sen sor Op en
orShortCircuit-Test
System Opera
tion Description:
Use this procedure under the following
conditions
:
Use this procedure if another procedure has directed
you here. Us
e this procedure if any of the following
diagnostic codes are active:
•
0094-03 Fu
el Pressure Sensor voltage above
normal
•
0094-04 Fu
el Pressure Sensor voltage below
normal
•
0100-03 E
ngine Oil Pressure Sensor voltage
above normal
•
0100-04
Engine Oil Pressure Sensor voltage below
normal
•
0100-10
Engine Oil Pressure Sensor abnormal
rate of change
•
1785-0
3 Intake Manifold Pressure Sensor voltage
above normal
•
1785-0
4 Intake Manifold Pressure Sensor voltage
below normal
•
1785-
10 Intake Manifold Pressure Sensor
abnormal rate of change
•
0127-
03 Transmission Oil Pressure Sensor voltage
above normal
•
0127
-04 Transmission Oil Pressure Sensor voltage
below normal
•
1797
-03 Fuel Rail Pressure Sensor voltage above
normal
•
179
7-04 Fuel Rail Pressure Sensor voltage below
normal
The
following background information is r elated
to this procedure:
The troubleshooting procedures for the diagnostic
codes of each pr
essure sensor are identical. The 5
V sensor supply provides power to all 5 V sensors.
The Electronic Control Module (ECM) supplies 5.0 ±
0.2 VDC to term
inal “A” of each sensor connector.
The sensor common from the ECM connector goes
to terminal “B” of each sensor connector. The sensor
supply is out
put short circuit protected. A short circuit
to the battery will not damage the circuit inside the
ECM.
Pull-up Voltage
The ECM cont
inuously outputs a pull-up voltage
on the circuit for the sensor signal wire. The ECM
uses this pull-up voltage in order to detect an open
in the sign
al circuit. When the ECM detects the
presence of a voltage that is above a threshold on the
signal circuit, the ECM will generate an open circuit
diagnosti
c code (03) for the sensor.
If the sensor is disconnected at the sensor connector,
the prese
nce of pull-up voltage at the sensor
connector indicates that the wires from the sensor
connector to the ECM are not open or shorted to
ground. I
f the sensor is disconnected at the sensor
connector, the absence of pull-up voltage at the
sensor connector indicates an open in the signal wire
or a shor
t to ground. If the sensor is disconnected at
the sensor connector and the voltage at the sensor
connector is different from pull-up voltage, the signal
wire is s
horted to another wire in the harness.
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