1998 ISUZU TROOPER check engine

6E±80
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0183 (Flash DTC 15)
FT Sensor High Voltage
060RW129
Circuit Description
The fuel temperature (FT) sensor is a thermistor mounted
in on a coolant crossover pipe at the rear of the engine.
The Engine Control Module ECM applies a voltage (about
5 volts) through a pull-up resistor to the FT signal circuit.
When the fuel is cold, the sensor (thermistor) resistance
is high, therefore the ECM will measure a high signal
voltage. As the fuel warms, the sensor resistance
becomes less, and the FT signal voltage measured at the
ECM drops.
Action Taken When the DTC Sets

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P0183 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
Check for the following conditions:

Poor connection at ECM ± Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
FT display on the Tech 2 while moving connectors and
wiring harnesses related to the FT sensor. A change
in the FT display will indicate the location of the fault.
If DTC P0182 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.

6E±81 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0183 ± FT Sensor High Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªON,º engine ªOFF.º
2. Observe the ªFuel Tempº display on the Tech 2.
Is the ªFuel Tempº below the specified value?
±39
C
(±38
F)
Go to Step 4Go to Step 3
31. Ignition ªON,º engine ªOFF.º
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor the ª DTCº info for DTC
P0183.
Does the Tech 2 indicate DTC P0183 failed?
Ð
Refer to Test
Description
Refer to
Diagnostic
Aids
41. Disconnect the FT sensor electrical connector.
2. Jumper the FT signal circuit and the sensor ground
circuit together at the FT sensor harness connector.
3. Observe the ªFuel Tempº display on the Tech 2.
Is the ªFuel Tempº at the specified value?
140
C
(284
F)
Go to Step 6Go to Step 5
51. Jumper the FT signal circuit at the FT sensor
harness connector to chassis ground.
2. Observe the ªFuel Tempº display on the Tech 2.
Is the ªFuel Tempº at the specified value?
140
C
(284
F)
Go to Step 7Go to Step 8
6Check for poor connections at the FT sensor and
replace terminals if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 10
71. Ignition ªOFF.º
2. Disconnect the ECM, and check the FT sensor
ground circuit for an open.
3. If the FT sensor ground circuit is open, repair it as
necessary.
Was the FT sensor ground circuit open?
ÐVerify repairGo to Step 9
81. Ignition ªOFF.º
2. Disconnect the ECM, and check the FT signal
circuit for an open.
3. If the FT sensor signal circuit is open, repair it as
necessary.
Was the FT signal circuit open?
ÐVerify repairGo to Step 9
9Check for a poor sensor ground or FT signal circuit
terminal connection at the ECM and replace
terminal(s) if necessary.
Did any of the terminals need to be replaced?
ÐVerify repairGo to Step 11
10Replace the FT sensor.
Is the action complete?
ÐVerify repairÐ
11Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±82
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0192 (Flash DTC 63)
Rail Pressure Sensor Low Voltage
060RW135
Circuit Description
The rail pressure (RP) sensor responds to changes in oil
manifold pressure.
The ECM monitors the RP signals for voltages outside the
normal range of the RP sensor. If the ECM detects a RP
signal voltage that is excessively low, DTC P0192 will be
set.
Action Taken When the DTC Sets

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P0192 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
Check for the following conditions:

Poor connection at ECM ± Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
RP display on the Tech 2 while moving connectors and
wiring harnesses related to the sensor. A change in the
display will indicate the location of the fault.
If DTC P0192 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently,
performing the DTC P0192 Diagnostic Chart may isolate
the cause of the fault.

6E±83 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0192 ± RP Sensor Low Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªON,º engine ªOFF.º
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ªDTCº info for DTC P0192.
Does the Tech 2 indicate DTC P0192 failed?
ÐGo to Step 3
Refer to
Diagnostic
Aids
3Check the RP sensor signal circuit.
Was the RP sensor signal circuit open or darmage?
Ð
Replace the
RP circuit.
Go to Step 4
41. Ignition ªOFF.º
2. Disconnect the ECM and check the 5 volt reference
ªJ1º circuit for an open or short to ground.
3. If the 5 volt reference ªJ1º circuit is open or shorted
to ground, repair it as necessary.
Was the 5 volt reference ªJ1º circuit open or shorted to
ground?
ÐVerify repairGo to Step 5
5Check the 5 volt reference ªJ1º circuit for a poor
connection at the ECM and replace the terminal if
necessary.
Did the terminal require replacement?
ÐVerify repairGo to Step 6
61. Ignition ªOFF.º
2. Disconnect the ECM, and check the RP signal
circuit for an open, short to ground, or short to the
sensor ground circuit.
3. If the RP sensor signal circuit is open or shorted to
ground, repair it as necessary.
Was the RP signal circuit open or shorted to ground?
ÐVerify repairGo to Step 7
7Check the RP sensor signal circuit for a poor
connection at the ECM and the RP sensor; replace the
terminal if necessary.
Did the terminal require replacement?
ÐVerify repairGo to Step 8
8Replace the RP sensor (Refer to the RP sensor
programming).
Is the action complete?
ÐVerify repairGo to Step 9
9Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±84
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0193 (Flash DTC 63)
Rail Pressure Sensor High Voltage
060RW135
Circuit Description
The rail pressure (RP) sensor responds to changes in oil
manifold pressure.
The ECM monitors the RP signals for voltages outside the
normal range of the RP sensor. If the ECM detects a RP
signal voltage that is excessively high, DTC P0193 will be
set.
Action Taken When the DTC Sets

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P0193 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
Check for the following conditions:

Poor connection at ECM ± Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
RP display on the Tech 2 while moving connectors and
wiring harnesses related to the sensor. A change in the
display will indicate the location of the fault.
If DTC P0193 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set. If
it is determined that the DTC occurs intermittently,
performing the DTC P0193 Diagnostic Chart may isolate
the cause of the fault.

6E±85 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0193 ± RP Sensor High Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªON,º engine ªOFF.º
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ª DTCº info for DTC P0108.
Does the Tech 2 indicate DTC P0108 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
3Check the RP sensor signal circuit.
Was the RP sensor signal circuit open or darmage?
Ð
Replace the
RP circuit
Go to Step 4
4Probe the sensor ground circuit with a test light to B+.
Is the test light ªON?º
ÐGo to Step 5Go to Step 7
51. Check the RP signal circuit for a short to voltage or a
short to the 5 volt reference ªJ1º circuit.
2. If the RP sensor signal circuit is shorted, repair
circuit as necessary.
Was the RP sensor signal circuit shorted?
ÐVerify repairGo to Step 6
61. Check for a poor sensor ground terminal connection
at the RP sensor electrical connector.
2. If a problem if found, replace the faulty terminal.
Did the terminal require replacement?
ÐVerify repairGo to Step 7
71. Check for a poor sensor ground terminal connection
at the ECM.
2. If a problem is found, replace the faulty terminal.
Did the terminal require replacement?
ÐVerify repairGo to Step 8
81. Check the continuity of the RP sensor ground
circuit.
2. If the RP sensor ground circuit measures over 5
ohms, repair open or poor connection.
Was a condition found and corrected?
ÐVerify repairGo to Step 9
9Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify RepairÐ

6E±86
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1193 (Flash DTC 64)
RPCV Circuit Open/Short
060RW135
Circuit Description
The rail pressure control valve (RPCV) is built in the high
pressure oil circuit.
RPCV is an important device which is used to control oil
pressure in the HEUI system.
The circuit receives current through Engine 15A fuse from
the battery, current flowing in the order of RPCV.
Action Taken When the DTC Sets

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P1193 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
Check for the following conditions:

Poor connection at ECM ± Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
RPCV display on the Tech 2 while moving connectors
and wiring harnesses related to the RPCV. A change
in the RPCV display will indicate the location of the
fault.
If DTC P1193 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently.

6E±87 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P1193 ± RPCV Circuit Open/Short

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªON,º engine ªON.º
2. Observe the ªRail Oil Pressureº display on the Tech
2.
Is the ªRail Oil Pressureº below the specified value?
3.5 ~ 5 MpaGo to Step 4Go to Step 3
3Replace the RPCV.
Is the action complete?
ÐGo to Step 2Ð
41. Engine ªOnº.
2. Using the Tech 2, operate ªRPCVº.
3. Check the combustion noise.
Was the combustion noise change?
ÐÐGo to Step 5
5Check the RPCV circuit. (Fuse 15A to J1-14)
Was the RPCV circuit damaged?
ÐGo to Step 6Go to Step 7
6Repair the RPCV circuit.
Is the action complete?
ÐVerify repairÐ
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairGo to Step 8
8Replace the high pressure oil pump.
Is the action complete?
ÐVerify repairÐ