headlights ISUZU TROOPER 1998 Service Repair Manual

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

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±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

8DÐ134 WIRING SYSTEM
Diagnosis
Quick Chart for Check Points
1. Headlight (RHD)
Check point
Trouble modeFuse
F–4
(15A)F–5
(15A)Lighting
relayLighting
SWDimmer•
Passing
SWCable
harness Headlight
bulb
1–1. Both Headlights inoperative
1–2. Headlight on the left (or
right) side inoperative
1–3. Both headlights in
low-beam inoperative
1–4. Headlight low-beam on
the left (or right) side
inoperative
1–5. Both headlights in
high–beam inoperative
1–6. Headlight high-beam on the
left (or right) side
inoperative
1–7. Headlight beam does not
change
LH RH
1–8. Headlights remain on when
the lighting SW is turned off
1–9. Headlights come on with
the lighting SW at the
clearance light position
1–10. Passing lights inoperative

WIRING SYSTEM 8DÐ135
Check point
Trouble modeFuse
F–4
(10A)F–5
(10A)Dimmer
relayLighting
SWDimmer•
Passing
SWCable
harness Headlight
bulb
2–1. Both Headlights
inoperative
2–2. Headlight on the
left (or right) side
inoperative
2–3. Both headlights
in low-beam
inoperative
2–4. Headlight low-
beam on the left
(or right)
side inoperative
2–5. Both headlights
in high-beam
inoperative
2–6. Headlight
high-beam on
the left (or right)
side inoperative
2–7. Headlight beam
does not change
Lighting
relayF–6
(10A)F–7
(10A)
2–8. Headlights
remain
on when the
lighting SW is
turned off
2–9. Headlights come
on with the
lighting SW at
the clearance
light position
Diode
2–10. Passing lights
inoperative
LH
RH
2. Headlight (LHD)

WIRING SYSTEM 8DÐ137
1-1. Both Headlights Inoperative
·IS THE LIGHTING RELAY NORMAL?
YES
·IS B-19 GROUNDED SECURELY?
YES
REPLACE THE LIGTHING RELAY
NO
·DISCONNECT THE LIGTHING SW CONNECTOR
·IS THE BATTERY VOLTAGE APPLIED BETWEEN THE HARNESS
SIDE CONNECTOR 1 B-12 AND GROUND?
YES
GROUND IT SECURELY
NO
·REMOVE THE LIGHTING SW
·IS THERE CONTINUITY BETWEEN 1 B-12 AND 7 B-12 WHEN
SETTING THE LIGHTING SW AT THE HEADLIGHT POSITION ?REPAIR A POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN THE FUSUBLE LINK
FL-1 (80A) AND 1 B-12
NO
YES
REPAIR OR REPLACE THE LIGHTING SW
NO
REPAIR A POOR CONNECTION AT THE CONNECTORS OR AN
OPEN CIRCUIT BETWEEN THE HARNESS SIDE CONNECTOR
7 B-12 AND B-19
·IS THE DIODE NORMAL?
REPLACE THE DIODE
NOYES

8DÐ138 WIRING SYSTEM
1-2. Headlight On The Left (Or Right) Side Inoperative
1-3. Both Headlights In Low-Beam Inoperative
YES
·IS THE HEADLIGHT BULB ON THE LEFT (OR RIGHT)
SIDE NORMAL?
YES
REPLACE THE FUSE
NO
·IS THE FUSE F-4 (15A) (OR F-5 (15A)) NORMAL?
REPAIR A POOR CONNECTION AT THE CONNECTORS OR AN
OPEN CIRCUIT BETWEEN
FUSE F-4 (15A) AND 3 C-21 (LH)
FUSE F-5 (15A) AND 3 C-32 (RH)REPLACE THE BULB
NO
·
YES
REPAIR A POOR CONNECTION AT THE CONNECTORS OR
AN OPEN CIRCUIT BETWEEN
13 B-12 AND 10 H-15REPAIR OR REPLACE THE DIMMER•PASSING SWNO
·WITH THE SWITCH AT THE LOW-BEAM POSITION, IS
THERE CONTINUITY BETWEEN THE SW CONNECTOR
TERMINALS 13 B-12 AND 16 B-12
DISCONNECT THE DIMMER•PASSING SW CONNECTOR
(COMBINATION SW)

8DÐ140 WIRING SYSTEM
1Ð5. Both Headlights In High-Beam Inoperative
·DISCONNECT THE DIMMER•
PASSING SW CONNECTOR (COMBINATION SW)
YES
REPAIR A POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN
15 B-12 AND 16 H-16REPAIR OR REPLACE THE DIMMER•
PASSING SW
NO
·WITH THE SWITCH AT HIGH-BEAM, IS THERE
CONTINUITY BETWEEN THE SWITCH CONNECTOR TERMINALS
15 B-12 AND 16 B-12 ?
1Ð6. Headlight High-Beam On The Left (Or Right) Side Inoperative
·IS THE HEADLIGHT BULB ON THE
LEFT (OR RIGHT) SIDE NORMAL?
YES
·IS THE FUSE F–4 (15A) (OR F–5 (15A))
NORMAL?
YES
REPLACE THE BULB
NO
·DISCONNECT THE DIMMER·PASSING SW CONNECTOR
·WITH THE SWITCH AT THE HIGH–BEAM POSITION, IS THERE
CONTINUITY BETWEEN 15 B–12 AND 16 B–12 ?
YES
REPLACE THE FUSE
NO
REPAIR A POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN 3 C–21 AND F–4
(15A) (OR 3 C–32 AND F–5 (15A))
NO
REPAIR OR REPLACE THE DIMMER·PASSING SWREPAIR A POOR CONNECTION AT THE CONNECTORS OR AN
OPEN CIRCUIT BETWEEN 15 B–12 AND 2 C–21 (OR 15 B–12
AND 2 C–32 )
·IS THE CONTINUITY BETWEEN
3 C–21 AND F–4 (15A) (OR 3 C–32
AND F–5 (15A)) NORMAL?
NOYES

WIRING SYSTEM 8DÐ141
1-7. Headlight Beam Does Not Change
1-8. Headlights Remain On When The Lighting SW Is Turned Off
YES
·DISCONNECT THE DIMMER•PASSING
SWREPAIR OR REPLACE THE DIMMER•PASSING SW
NO
·DOES THE LEVER OF THE DIMMER•
PASSING SW OPERATE SMOOTHLY AND SECURELY?
·WITH THE SWITCH AT THE LOW-BEAM POSITION, IS
THERE CONTINUITY BETWEEN 13 B-12 AND 16 B-12 ?
ALSO, WITH IT AT THE HIGH-BEAM POSITION, IS THERE
CONTINUITY BETWEEN 15 B-12 AND 16 B-12 ?
NO
REPAIR OR REPLACE THE DIMMER•PASSING SW
YES
·REPLACE THE LIGHTING RELAY
NO
·IS THE LIGHTING RELAY NORMAL?
REPAIR OR REPLACE THE LIGHTING SW
NO
DISCONNECT THE LIGHTING SW CONNECTOR
·IS THE CONTINUITY BETWEEN
THE SWITCH CONNECTOR TERMINALS 1 B-12 AND
7 B-12 NORMAL?
YES
REPAIR A SHORT CIRCUIT BETWEEN
5 X-1 AND 1 B-12

8DÐ142 WIRING SYSTEM
REPAIR OR REPLACE THE LIGHTING SW
1-10. Passing Lights Inoperative
·DISCONNECT THE DIMMER•PASSING SW CONNECTOR
YES
REPAIR A POOR CONNECTION AT THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN 5 H-15 AND
14 B-12 REPAIR OR REPLACE THE SWITCH
NO
·WITH THE SWITCH AT PASSING POSITION, IS THERE
CONTINUITY BETWEEN THE SWITCH CONNECTOR TERMINALS
14 B-12 AND 16 B-12 , AND 15 B-12 AND 16 B-12 ?
1-9. Headlights Come On With The Lighting SW At The Clearance Light Position