1998 ISUZU TROOPER electrical system

6E±79 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0182 ± FT 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. Observe the ªFuel Tempº display on the Tech 2.
Is the ªFuel Tempº below the specified value?
139
C
(282
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 ª DTCº info for DTC P0182.
Does the Tech 2 indicate DTC P0182 failed this
ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Disconnect the FT sensor electrical connector.
2. Observe the ªFuel Tempº display on the Tech 2.
Is the ªFuel Tempº at the specified value?
±39
C
(±38
F)
Go to Step 6Go to Step 5
51. Ignition ªOFF.º
2. Disconnect the ECM and check the FT signal circuit
for a short to ground or a short to the sensor ground
circuit.
3. If the FT signal circuit is shorted. repair it as
necessary.
Was the FT signal circuit shorted to ground?
ÐVerify repairGo to Step 7
6Replace the FT sensor.
Is the action complete?
ÐVerify repairÐ
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

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±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±95 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.
3. If DTC P0197 can be repeated only by duplicating
the Failure Records conditions, refer to the
ªTemperature vs. Resistance Valuesº table. The
table may be used to test the OT sensor at various
temperatures to evaluate the possibility of a
ªshiftedº sensor that may be shorted above or below
a certain temperature. If this is the case, replace
the OT sensor. If the OT sensor appears to be OK,
the fault is intermittent; refer to
Diagnostic Aids.
Engine Oil Temperature Sensor

C
FOhms
Temperature vs. Resistance Values
(approximate)
80176332
25772796
15594450
DTC P0197 ± OT 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. Observe the ªEng Oil Tempº display on the Tech 2.
Is the ªEng Oil Tempº below the specified value?
139
C
(282
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 ª DTCº info for DTC P0197.
Does the Tech 2 indicate DTC P0197 failed this
ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Disconnect the OT sensor electrical connector.
2. Observe the ªEng Oil Tempº display on the Tech 2.
Is the ªEng Oil Tempº at the specified value?
±39
C
(±38
F)
Go to Step 6Go to Step 5
51. Ignition ªOFF.º
2. Disconnect the ECM and check the OT signal circuit
for a short to ground or a short to the sensor ground
circuit.
3. If the OT signal circuit is shorted. repair it as
necessary.
Was the OT signal circuit shorted to ground?
ÐVerify repairGo to Step 7
6Replace the OT sensor.
Is the action complete?
ÐVerify repairÐ
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±97 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.
3. If DTC P0198 can be repeated only by duplicating
the Failure Records conditions, refer to the
ªTemperature vs. Resistance Valueº table. The
table may be used to test the OT sensor at various
temperatures to evaluate the possibility of a
ªshiftedº sensor that may be shorted above or below
a certain temperature. If this is the case, replace
the OT sensor. If the OT sensor appears to be OK,
the fault is intermittent; refer to
Diagnostic Aids.
Engine Oil Temperature Sensor

C
FOhms
Temperature vs. Resistance Values
(approximate)
80176332
25772796
15594450
DTC P0198 ± OT 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 ªEng Oil Tempº display on the Tech 2.
Is the ªEng Oil 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
P0198.
Does the Tech 2 indicate DTC P0198 failed?
Ð
Refer to Test
Description
Refer to
Diagnostic
Aids
41. Disconnect the OT sensor electrical connector.
2. Jumper the OT signal circuit and the sensor ground
circuit together at the OT sensor harness
connector.
3. Observe the ªEng Oil Tempº display on the Tech 2.
Is the ªEng Oil Tempº at the specified value?
140
C
(284
F)
Go to Step 6Go to Step 5
51. Jumper the OT signal circuit at the OT sensor
harness connector to chassis ground.
2. Observe the ªEng Oil Tempº display on the Tech 2.
Is the ªEng Oil Tempº at the specified value?
140
C
(284
F)
Go to Step 7Go to Step 8
6Check for poor connections at the OT 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 OT sensor
ground circuit for an open.
3. If the OT sensor ground circuit is open, repair it as
necessary.
Was the OT sensor ground circuit open?
ÐVerify repairGo to Step 9

6E±147 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P1486 ± ITP 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. With the throttle closed by the hand, observe the
ªITP Sensorº display on the Tech 2.
Is the ªITP Sensorº above the specified value?
4.88 VGo 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 ªDTCº info for DTC P1486.
Does the Tech 2 indicate DTC P1486 failed.
ÐGo to Step 4
Refer to
Diagnostic
Aids
4Check for poor electrical connections at the ITP sensor
and replace terminals if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 5
51. 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 ªDTCº info for DTC
P1486.
Dose the Tech 2 indicate DTC P1486 failed.
ÐGo to Step 6
Refer to
Diagnostic
Aids
6Replace the intake throttle.
Is the action complete?
ÐVerify repairGo to Step 7
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±159 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0562 (Flash DTC 35)
System Voltage Too Low
Circuit Description
The engine control module (ECM) monitors the system
voltage on the ignition feed terminals to the ECM. A
system voltage DTC will set whenever the voltage is
above a calibrated value.
Action Taken When the DTC Sets

The ECM will not illuminate the malfunction indicator
lamp (MIL).

The ECM will store as Failure Records only conditions
which were present when the DTC was set. This
information will not be stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC

DTC P0563 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
If the DTC sets when an accessory is operated, check for
a poor connection or defective accessory.
DTC P0562 ± System Voltage Too Low

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Using a DVM, measure the battery voltage at the
battery.
Is the battery voltage greater than the specified value?
11.5 VGo to Step 3
Charge
battery, then
go to
Step 3
31. Install a Tech 2.
2. Select ªIgnition Voltsº on the Tech 2.
3. Start the engine and raise the engine speed to the
specified value.
4. Load the electrical system by turning on the
headlights, high blower, etc.
Is the ignition voltage approximately equal to the
specified value?
2000 RPM
12.8-14.1 V
Go to Step 4
Go to
Starting/
Charging
41. Ignition ªOFF.º
2. Disconnect the ECM connector at the ECM.
3. Using a DVM, measure the battery voltage at the
ECM connector.
Is it approximately equal to battery voltage?
Ð
Check for
excessive
current draw
with ignition
ªOFF,º engine
ªOFF.º
Go to Step 5
51. Check for faulty connections at the ECM harness
terminals.
2. Repair as necessary.
Was a repair necessary?
ÐVerify repairGo to Step 6
6Check for an open battery feed circuit to the ECM.
Is the action complete?
ÐVerify repairGo to Step 7
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±176
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the ªOn±Board
Diagnostic (OBD) System Checkº and verify all of the
following items:

The powertrain control module (ECM) and
malfunction indicator lamp (MIL) (CHECK ENGINE
lamp) are operating correctly.

There are no DTC(s) stored.

Tech±2 data is within normal operating range. Refer
to
Typical Scan Data Values.

Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.
Visual/Physical Check
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time.
This check should include the following items:

ECM grounds for cleanliness, tightness and proper
location.

Vacuum hoses for splits, kinks, and proper
connections, as shown on the ªVehicle Emission
Control Informationº label. Check thoroughly for any
type of leak or restriction.

Air intake ducts for collapsed or damaged areas.

Injector wires for cracking, hardness, and carbon
tracking.

Wiring for proper connections, pinches and cuts.
Intermittents
IMPORTANT:An intermittent problem may or may not
turn on the malfunction indicator lamp (MIL) or store a
DTC. DO NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems. The fault must be
present to locate the problem.
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions:

Poor mating of the connector halves or a terminal not
fully seated in the connector (backed out).

Improperly formed or damaged terminal.

All connector terminals in the problem circuit should
be carefully checked for proper contact tension.

Poor terminal±to±wire connection. This requires
removing the terminal from the connector body to
check.
Road test the vehicle with a Digital Multimeter
(5-8840-0285-0) connected to a suspected circuit. An
abnormal voltage when the malfunction occurs is a good
indication that there is a fault in the circuit being
monitored.
Use a scan tool to help detect intermittent conditions. The
scan tools have several features that can be used to
locate an intermittent condition. Use the following feature
to find intermittent faults:
Using a Tech±2 ªFreeze Frameº buffer or ªFailure
Recordsº buffer can aid in locating an intermittent
condition. Review and record the information in the
freeze frame or failure record associated with the
intermittent DTC being diagnosed. The vehicle can
be driven within the conditions that were present
when the DTC originally set.
To check for loss of diagnostic code memory, disconnect
the MAP sensor and idle the engine until the MIL (CHECK
ENGINE lamp) comes on. DTC P0107 should be stored
and kept in memory when the ignition is turned ªOFF.º If
not, the ECM is faulty. When this test is completed, make
sure that you clear the DTC P0107 from memory.
An intermittent MIL (CHECK ENGINE lamp) with no
stored DTC may be caused by the following:

MIL (CHECK ENGINE lamp) wire to ECM shorted to
ground.

Poor ECM grounds. Refer to the ECM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in
Electrical Diagnosis).
If problem has not been found, refer to
ECM Connector
Symptom
tables.