lights ISUZU TROOPER 1998 Service Repair Manual

00 – 10 SERVICE INFORMATION
Problem Possible Cause Correction
STEERING COLUMN (CONT.)
TURN SIGNAL SWITCH
This troubleshooting covers mechanical problems only. See Section 8 for turn signal switch electrical
diagnosis.
Turn Signal Will Not Stay
in Turn Position
Turn Signal Will Not
Cancel
Turn Signal Difficult to
Operate
Turn Signal Will Not
Indicate Lane Change
Hezard Switch Cannot Be
Turned Off
No Turn Signal Lights
Front or Rear Turn Signal
Lights Not Flashing1. Foreign material or loose parts
preventing movement of yoke.
2. Broken or missing detent or canceling
spring.
1. Loose switch mounting screws.
2. Switch or anchor bosses broken.
3. Broken, missing or out of position
detent, return or canceling spring.
4. Worn canceling cam.
1. Turn signal switch arm loose.
2. Yoke broken or distorted.
3. Loose or misplaced springs.
4. Foreign parts and/or material.
5. Loose turn signal switch mounting
screws.
1. Broken lane change pressure pad or
spring hanger.
2. Broken, missing or misplaced lane
change spring.
3. Base of wire damaged.
1. Foreign material between hazard
switch to turn signal switch body.
1. Electrical failure in chassis harness.
2. Inoperative turn signal flasher unit.
3. Loose chassis harness connector.
1. Burned-out damaged turn signal bulb.
2. High resistance connection to ground
at bulb socket.
3. Loose chassis harness connector.Repair or replace signal switch.
Replace signal switch.
Tighten mounting screws.
Replace turn signal switch.
Replace turn signal switch.
Replace turn signal switch.
Tighten arm screw.
Replace turn signal switch.
Replace turn signal switch.
Repair turn signal switch.
Tighten mounting screws.
Replace turn signal switch.
Replace turn signal switch.
Replace turn signal switch.
Repair or replace hazard
switch.
Refer to Section 8 “Electrical
Troubleshooting”.
Replace flasher unit.
Repair loose connector.
Replace bulb.
Repair bulb socket.
Repair loose connector.

6A±4
ENGINE MECHANICAL
Engine Diagnosis
Hard Starting
1. Starting Motor Does Not Turn Over
Troubleshooting Procedure
Turn on headlights and starter switch.
Condition
Possible causeCorrection
Headlights go out or dim
considerably
Battery run down or under chargedRecharge or replace battery
considerablyTerminals poorly connectedClean battery posts and terminals
and connect properly
Starting motor coil circuit shortedOverhaul or replace
Starting motor defectiveOverhaul or replace
2. Ignition Trouble Ð Starting Motor Turns Over But Engine Does Not Start
Spark Test
Disconnect an igniton coil from any spark plug. Connect
the spark plug tester 5±8840±0607±0, start the engine,
and check if a spark is generated in the spark plug tester.
Before starting the engine, make sure that the spark plugtester is properly grounded. To avoid electrical shock, do
not touch the part where insulation of the igniton coil is
broken while the engine is running.
Condition
Possible causeCorrection
Spark jumps across gapSpark plug defectiveClean, adjust spark gap or replace
Ignition timing incorrectRefer to Ignition System
Fuel not reaching fuel injector(s) or
engineRefer to item 3 (Trouble in fuel
system)
Valve timing incorrectAdjust
Engine lacks compressionRefer to item 4 (Engine lacks
compression)
No sparking takes placeIgnition coil disconnected or brokenConnect properly or replace
Electronic Ignition System with
moduleReplace
Poor connections in engine harnessCorrect
Powertrain Control Module cable
disconnected or defectiveCorrect or replace
3. Trouble In Fuel System
Condition
Possible causeCorrection
Starting motor turns over and spark
occurs but engine does not start
Fuel tank emptyFill
occurs but engine does not start.Water in fuel systemClean
Fuel filter cloggedReplace filter
Fuel pipe cloggedClean or replace
Fuel pump defectiveReplace
Fuel pump circuit openCorrect or replace
Evaporative Emission Control
System circuit cloggedCorrect or replace
Multiport Fuel Injection System faultyRefer to ªElectronic Fuel Injectionº
section

ENGINE ELECTRICAL6D1±3
a. VOLTAGE DOES NOT DROP BELOW THE
MINIMUM LISTED IN THE TABLE ± The battery is
good and should be returned to service.
b. VOLTAGE IS LESS THAN MINIMUM LISTED ±
Replace battery.
ESTIMATED TEMPERATURE
MINIMUM
VOLTAGE

F
CV
70219.6
60169.5
50109.4
4049.3
30±19.1
20±78.9
10±128.7
0±188.5
The battery temperature must be estimated by feel
and by the temperature the battery has been
exposed to for the preceding few hours.
Battery Charging
Observe the following safety precautions when charging
the battery:
1. Never attempt to charge the battery when the fluid
level is below the lower level line on the side of the
battery. In this case, the battery must be replaced.
2. Pay close attention to the battery during charging
procedure.
Battery charging should be discontinued or the rate of
charge reduced if the battery feels hot to the touch.
Battery charging should be discontinued or the rate of
charge reduced if the battery begins to gas or spew
electrolyte from the vent holes.
3. In order to more easily view the hydrometer blue dot
or ring, it may be necessary to jiggle or tilt the battery.
4. Battery temperature can have a great effect on
battery charging capacity.
5. The sealed battery used on this vehicle may be either
quick charged or slow charged in the same manner as
other batteries.
Whichever method you decide to use, be sure that
you completely charge the battery. Never partially
charge the battery.
Jump Starting
Jump Starting with an Auxiliary (Booster)
Battery
CAUTION: Never push or tow the vehicle in an
attempt to start it. Serious damage to the emission
system as well as other vehicle parts will result.Treat both the discharged battery and the booster
battery with great care when using jumper cables.
Carefully follow the jump starting procedure, being
careful at all times to avoid sparking.
WARNING: FAILURE TO CAREFULLY FOLLOW THE
JUMP STARTING PROCEDURE COULD RESULT IN
THE FOLLOWING:
1. Serious personal injury, particularly to your eyes.
2. Property damage from a battery explosion, battery
acid, or an electrical fire.
3. Damage to the electronic components of one or both
vehicles particularly.
Never expose the battery to an open flame or electrical
spark. Gas generated by the battery may catch fire or
explode.
Remove any rings, watches, or other jewelry before
working around the battery. Protect your eyes by wearing
an approved set of goggles.
Never allow battery fluid to come in contact with your eyes
or skin.
Never allow battery fluid to come in contact with fabrics or
painted surfaces.
Battery fluid is a highly corrosive acid.
Should battery fluid come in contact with your eyes, skin,
fabric, or a painted surface, immediately and thoroughly
rinse the affected area with clean tap water.
Never allow metal tools or jumper cables to come in
contact with the positive battery terminal, or any other
metal surface of the vehicle. This will protect against a
short circuit.
Always keep batteries out of reach of young children.
Jump Starting Procedure
1. Set the vehicle parking brake.
If the vehicle is equipped with an automatic
transmission, place the selector level in the ªPARKº
position.
If the vehicle is equipped with a manual transmission,
place the shift lever in the ªNEUTRALº position.
Turn ªOFFº the ignition.
Turn ªOFFº all lights and any other accessory
requiring electrical power.
2. Look at the built±in hydrometer.
If the indication area of the built±in hydrometer is
completely clear, do not try to jump start.
3. Attach the end of one jumper cable to the positive
terminal of the booster battery.
Attach the other end of the same cable to the positive
terminal of the discharged battery.
Do not allow the vehicles to touch each other. This will
cause a ground connection, effectively neutralizing
the charging procedure.
Be sure that the booster battery has a 12 volt rating.

6D3±19 STARTING AND CHARGING SYSTEM
Generator
Removal
1. Disconnect battery ground cable.
2. Move drive belt tensioner to loose side using wrench
then remove drive belt (1).
3. Disconnect the wire from terminal ªBº and disconnect
the connector (4).
4. Remove generator fixing bolt (3).
5. Remove generator assembly (2).
060RW002
Inspection
1. Disconnect the wiring connector from generator.
2. With the engine stopped, turn starter switch to ªONº
and connect a voltmeter between connector terminal
L (2) and ground or between terminal IG (1) and
ground.
066RW001If voltage is not present, the line between battery and
connector is disconnected and so requires repair.
3. Reconnect the wiring connector to the generator, run
the engine at middle speed, and turn off all electrical
devices other than engine.
4. Measure battery voltage. If it exceeds 16V, repair or
replace the generator.
5. Connect an ammeter to output terminal of generator,
and measure output current under load by turning on
the other electrical devices (eg., head lights). At this
time, the voltage must not be less than 13V.
Installation
1. Install generator assembly to the position to be
installed.
2. Install generator assembly and tighten the fixing bolts
to the specified torque.
Torque:
M10 bolt: 41 N´m (4.2 Kg´m/30 lb ft)
M8 bolt: 21 N´m (2.1 Kg´m/15 lb ft)
3. Connect wiring harness connector and direct terminal
ªBº.
4. Move drive belt tensioner to loose side using wrench,
then install drive belt to normal position.
5. Reconnect battery ground cable.

6E±146
ENGINE DRIVEABILITY AND EMISSIONS
indicates a signal line shorted to ground or signal lines
shorted together. Disconnect the HO2S and connect
a test light between the HO2S ignition feed and heater
ground circuits. If the test light does not light for 2
seconds when the ignition is turned on, repair the open
ignition feed or sensor ground circuit as necessary. If
the test light lights and the HO2S signal and low circuits
are OK, replace the HO2S.

Intermittent test ± With the Ignition ªON,º monitor the
HO2S signal voltage while moving the wiring harness
and related connectors. If the fault is induced, the
HO2S signal voltage will change. This may help isolate
the location of the malfunction.Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. If the DTC P0134 test passes while the Failure
Records conditions are being duplicated, an
intermittent conditions is indicated.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
DTC P0134 ±HO2S Circuit Insufficient Activity Bank 1 Sensor 1

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Install Tech 2.
2. Run the engine at operating temperature.
3. Operate the engine above 1200 RPM for two
minutes.
Does Tech 2 indicate Bank 1 HO2S 1 voltage varying
outside the specified values?
400-500 mVGo to Step 3Go to Step 4
31. Ignition ªON,º engine ªOFF,º review and record Tech
2 Failure Records data and note parameters.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using Tech 2, monitor ªSpecific DTCº info for DTC
P0134 until the DTC P0134 test runs.
4. Note the test result.
Does Tech 2 indicate DTC P0134 failed this ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
4Check for a damaged harness.
Was a problem found?
ÐVerify repairGo to Step 5
5Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the Bank 1 HO2S 1 harness
connector and replace terminal(s) if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 6
6Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the PCM and replace terminals
if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 7
71. Ignition ªOFF.º
2. With the PCM disconnected, check continuity of the
Bank 1 HO2S 1 high circuit.
3. If the Bank 1 HO2S 1 high circuit measures over 5.0
ohms, repair open or poor connection as necessary.
Was a Bank 1 HO2S 1 high circuit problem found and
corrected?
ÐVerify repairGo to Step 8

6E±226
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0404 EGR Open Stuck
D06RW106
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to commands from the PCM, and to
detect a fault if pintle position is different from
commanded position. If the PCM detects a pintle position
signal indicates more than 15 points different between
current and commanded and more than 15 seconds, the
PCM will set DTC P0404.
Conditions for Setting the DTC

Ignition voltage is between 11 and 16 volts.

Intake Air temp is more than 3
C.

Desire EGR position is more than 0.

The difference between desired EGR and current EGR
is less than 3%.

Difference EGR pintle position between current and
commanded position becomes more than 15% and
last more than 15 seconds, and this condition meets
three times in a trip. Then it trigger, the PCM lights on.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) as soon as failure detected after consecutive 2nd
trip in which the fault is detected.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in Failure
Records data.
Conditions for Clearing the MIL/DTC

DTC P0404 can be cleared by using Tech 2 ªClear Infoº
function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:

Excessive carbon deposit on EGR valve shaft may
cause EGR stuck open or unsmooth operation. Those
carbon deposit may occur by unusual port operation.
Clean up carbon may make smooth function of EGR
valve.

Poor connection or damaged harness ± Inspect the
wiring harness for damage. If the harness appears to
be OK, observe the EGR actual position display on
Tech 2 while moving connectors and wiring harnesses
related to EGR valve. A change in the display will
indicate the location of the fault.

6E±238
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0562 ± System Voltage 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 Tech 2, 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. Using 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/Char
ging
41. Ignition ªOFF.º
2. Disconnect the PCM connector at the PCM.
3. Using a DVM, measure the battery voltage at the
PCM connector A-4.
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 PCM harness
terminals.
2. Repair as necessary.
Was a repair necessary?
ÐVerify repairGo to Step 6
6Check for an open battery feed circuit to the PCM.
Is the action complete?
ÐVerify repairGo to Step 7
7Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±249 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1404 EGR Closed Stuck
D06RW106
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to commands from the PCM, and to
detect a fault if current pintle zero position is different from
the learned zero position. If the PCM detects a pintle
position signal indicates more than 30 % different
between current zero position and the learned zero
position and more than 5 seconds, and this condition
meet 3 times during trip, then the PCM will set DTC
P1404.
Conditions for Setting the DTC

Ignition voltage is between 11 and 16 volts.

Intake Air temp is more than 3
C.

Desire EGR position is 0.

Difference EGR pintle position between current and
the learned zero is more than 30 % last more than 5
seconds, and meet three time to the above condition
during a trip. Then it trigger the PCM lights on.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) after consecutive 2nd trip in which the fault is
detected.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in Failure
Records data.
Conditions for Clearing the MIL/DTC

DTC P1404 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

Excessive carbon deposit on EGR valve shaft or/and
foreign material may cause no return to EGR valve
fully seated. Those carbon deposit may occur by
unusual port operation. Remove foreign material
or/and excessive carbon deposit on EGR valve shaft
may make return to EGR valve fully seated.

Poor connection or damaged harness ± Inspect the
wiring harness for damage. Same as P1406
description
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.

6E±262
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 (PCM) and malfunction
indicator lamp (MIL) (Service Engine Soon 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:

PCM 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.

Air leaks at throttle body mounting area, mass air flow
(MAF) sensor and intake manifold sealing surfaces.

Ignition 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 J 39200 Digital Multimeter
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 Tech 2 to help detect intermittent conditions. Tech 2s
have several features that can be used to locate anintermittent condition. Use the following feature to find
intermittent faults:

Using Tech 2's 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 (Service
Engine Soon lamp) comes on. DTC P0107 should be
stored and kept in memory when the ignition is turned
ªOFF.º If not, the PCM is faulty. When this test is
completed, make sure that you clear the DTC P0107 from
memory.
An intermittent MIL (Service Engine Soon lamp) with no
stored DTC may be caused by the following:

Ignition coil shorted to ground and arcing at ignition
wires or plugs.

MIL (Service Engine Soon lamp) wire to PCM shorted
to ground.

Poor PCM grounds. Refer to the PCM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc. Route ignition coil wiring
away from the ignition coils. Check all wires from the
PCM to the ignition coil for poor connections.
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
PCM Connector
Symptom
tables.

ENGINE ELECTRICAL 6D1 Ð 3
BATTERY CHARGING
Observe the following safety precautions when
charging the battery:
1. Never attempt to charge the battery when the
fluid level is below the lower level line on the
side of the battery. In this case, the battery
must be replaced.
2. Pay close attention to the battery during the
charging procedure.
Battery charging should be discontinued or the
rate of charge reduced if the battery feels hot to
the touch.
Battery charging should be discontinued or the
rate of charge reduced if the battery begins to
gas or spew electrolyte from the vent holes.
3. In order to more easily view the hydrometer
blue dot or ring, it may be necessary to jiggle or
tilt the battery.
4. Battery temperature can have a great effect on
battery charging capacity.
5. The sealed battery used on this vehicle may be
either quick-charged or slow-charged in the
same manner as other batteries.
Whichever method you decide to use, be sure
that you completely charge the battery. Never
partially charge the battery.
JUMP STARTING
JUMP STARTING WITH AN AUXILIARY
(BOOSTER) BATTERY
CAUTION:
Never push or tow the vehicle in an attempt to
start it. Serious damage to the emission system
as well as other vehicle parts will result.
Treat both the discharged battery and the
booster battery with great care when using
jumper cables. Carefully follow the jump
starting procedure, being careful at all times to
avoid sparking.
WARNING:
Failure to carefully follow the jump starting
procedure could result in the following:
1. Serious personal injury, particulaly to
your eyes.
2. Property damage from a battery explo-
sion, battery acid, or an electrical fire.
3. Damage to the electronic components of
one or both vehicles particularly. Never expose the battery to an open flame or elec-
trical spark. Gas generated by the battery may catch
fire or explode.
Remove any rings, watches, or other jewelry before
working around the battery. Protect your eyes by
wearing an approved set of goggles.
Never allow battery fluid to come in contact with
your eyes or skin.
Never allow battery fluid to come in contact with
fabrics or painted surfaces.
Battery fluid is a highly corrosive acid.
Should battery fluid come in contact with your
eyes, skin, fabric, or a painted surface, immediately
and thoroughly rinse the affected area with clean
tap water.
Never allow metal tools or jumper cables to come
in contact with the positive battery terminal, or any
other metal surface of the vehicle. This will protect
against a short circuit.
Always keep batteries out of the reach of young
children.
JUMP STARTING PROCEDURE
1. Set the vehicle parking brake.
If the vehicle is equipped with an automatic
transmission, place the selector lever in the
ÒPARKÓ position.
If the vehicle is equipped with a manual trans-
mission place the shift lever in the ÒNEUTRALÓ
position.
Turn ÒOFFÓ the ignition.
Turn ÒOFFÓ all lights and any other accessory
requiring electrical power.
2. Look at the built-in hydrometer.
If the indication area of the built-in hydrometer
is completely clear, do not try to jump start.
3. Attach the end of one jumper cable to the posi-
tive terminal of the booster battery.
Attach the other end of the same cable to the
positive terminal of the discharged battery.
Do not allow the vehicles to touch each other.
This will cause a ground connection, effectively
neutralizing the charging procedure.
Be sure that the booster battery has a 12 volt
rating.
4. Attach one end of the remaining cable to the
negative terminal of the booster battery.
Attach the other end of the same cable to a
solid engine ground (such as the A/C com-
pressor bracket or the generator mounting
bracket) of the vehicle with the discharged bat-
tery.
This ground connection must be at least 450
mm (18 in) from the battery of the vehicle
whose battery is being charged.
ON-VEHICLE SERVICE