Page 690 of 4264

8A-32 ELECTRICAL-BODY AND CHASSIS
FUSE AND SLOW BLOW FUSE LOCATION (RELAY AND FUSE BOX)
RELAY & FUSE BOX
LHD
FUSE Saudi Arabia
ENGINE MODEL
FUSE NO. C24SE 6VE1 4JA1-TC / 4JH1-TC4JA1-L
EB-1 15A ECM 20A ECM 10A ECM
EB-2
10A ECM (B) 10A RR FOG
EB-3 15A FRT FOG
10A TCM 15A FRT FOG
EB-4 10A ACG (S) 15A FRT FOG 10A ACG (S)
EB-5 10A ILLUMI & TAIL-RH 10A ILLUMI & TAIL-RH
EB-6 10A TAIL-LH 10A TAIL-LH
EB-7 10A H/LIGHT-RH 10A H/LIGHT-RH
10A H/LIGHT-RH-LOW
10A H/LIGHT RH-LOW
10A H/LIGHT-RH-LOW
EB-8 10A H/LIGHT-LH 10A H/LIGHT-LH
10A H/LIGHT-LH-LOW
10A H/LIGHT LH-LOW
10A H/LIGHT-LH-LOW
EB-9 20A FUEL PUMP 10A O2 SENSOR 10A TRA ILER
EB-10 10A O2 SENSOR 20A FUEL PUMP 10A AC G (S)
EB-11 10A H/LIGHT-RH-HIGH 10A H/LIGHT RH-HIGH
EB-12 10A H/LIGHT-LH-HIGH 10A H/LIGHT LH-HIGH
EB-13 10A A/C
EB-14 10A 4WD
10A 4WD
EB-15 10A HORN
EB-16 15A HAZARD 10A HAZARD
SLOW BLOW FUSE
ENGINE MODEL
FUSE NO. C24SE 6VE1 4JA1-TC / 4JH1-TC4JA1-L
SBF-1 100A MAIN
80A MAIN
SBF-2
20A COND, FAN
SBF-3
60A GLOW 20A COND, FAN
SBF-4 20A COND, FAN
30A ECM 50A GLOW
SBF-5 40A IG 1
SBF-6
40A ABS-1
SBF-7
30A ABS-2
SBF-8 30A BLOWER
SBF-9 50A IG 2
Page 691 of 4264
ELECTRICAL-BODY AND CHASSIS 8A-33
FUSE LOCATION
RHD/LHD
RTW38DMF000101
FUSE
!"#
$% & %'
& '( )$!"#
)$ * )
* $ + $$,-$
+ % . $(
. / '$
/ -$0( $$
%
SLOW BLOW FUSE
- -
- (00 0
FUSE BOX
Page 692 of 4264
8A-34 ELECTRICAL-BODY AND CHASSIS
DIODE LOCATION
RELAY & FUSE BOX
DIODE
C24SE 6VE1 4JA1-TC / 4JH1-TC 4JA1-L
No.
RHD LHD RHD LHD RHD LHD RHD LHD
X-16 TCM TCM A/C
X-17 A/C A/T, A/C A/C A/C A/C
Page 1373 of 4264

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–1
ENGINE
CONTENTS
4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
ABBREVIATION CHARTS ........................ 6E-9
4JA1-TC .................................................... 6E-10
4JH1-TC .................................................... 6E-11
ECM CIRCUIT DIAGRAM (4JA1-TC) ........ 6E-14
ECM CIRCUIT DIAGRAM (4JA1-TC) ........ 6E-15
ECM CIRCUIT DIAGRAM (4JH1-TC) ........ 6E-16
ECM CIRCUIT DIAGRAM (4JH1-TC) ........ 6E-17
GROUND POINT CHART GENERAL EXPORT
(LHD) (1/4) ............................................... 6E-18
LOCATION ................................................ 6E-34
PARTS LOCATION ................................... 6E-39
CONNECTOR LIST ................................... 6E-40
RELAY AND FUSE .................................... 6E-43
RELAY AND FUSE BOX LOCATION
(LHD & RHD) ........................................... 6E-43
RELAY AND FUSE BOX LOCATION
(LHD & RHD) ........................................... 6E-44
FUSE AND RELAY LOCATION (LHD & RHD) 6E-45
ECM WIRING DIAGRAM (1/7) .................. 6E-46
ECM WIRING DIAGRAM (2/7) .................. 6E-47
ECM WIRING DIAGRAM (3/7) .................. 6E-48
ECM WIRING DIAGRAM (4/7) .................. 6E-49
ECM WIRING DIAGRAM (5/7) .................. 6E-50
ECM WIRING DIAGRAM (6/7) .................. 6E-51
ECM WIRING DIAGRAM (7/7) .................. 6E-52
ECM CONNECTOR PIN ASSIGNMENT &
OUTPUT SIGNAL .................................... 6E-53
GENERAL DESCRIPTION FOR ECM AND
SENSORS ............................................... 6E-64
Engine Control Module (ECM) ................... 6E-64
Pump Control Unit (PSG) & Data Ex change
Between Control Module ......................... 6E-64
Mass Air Flow (MAF) Sensor & Intake Air
Temperature (IAT) Sensor ....................... 6E-65
Throttle Position Sensor (TPS) .................. 6E-66
Crankshaft Position (CKP) Sensor ............ 6E-66
Engine Coolant Temperature (ECT) Sensor 6E-67
Vehicle Speed Sensor (VSS) .................... 6E-67
GENERAL DESCRIPTION FOR EGR
(EXHAUST GAS RE-CIRCULATION) ..... 6E-68
GENERAL DESCRIPTION FOR
INJECTION PUMP .................................. 6E-70Outline ....................................................... 6E-70
Cross-section View .................................... 6E-70
Low Pressure Fuel Circuit .......................... 6E-71
High Pressure Fuel Circuit ......................... 6E-72
Pump Camshaft Speed Sensor ................. 6E-72
High Pressure Solenoid Valve ................... 6E-73
Timing Control Valve (TCV) ....................... 6E-74
ISUZU Strategy Based Diagnostics .............. 6E-76
Overview .................................................... 6E-76
STRATEGY BASED DIAGNOSTICS CHART 6E-76
Diagnostic Thought Process ...................... 6E-77
1. Verify the Complaint .............................. 6E-77
2. Perform Preliminary Checks .................. 6E-77
3. Check Bulletins and Troubleshooting Hints 6E-78
4. Perform Service Manual Diagnostic Checks 6E-78
5a and 5b. Perform Service Manual Diagnostic
Procedures .............................................. 6E-78
5c. Technician Self Diagnoses .................. 6E-78
5d. Intermittent Diagnosis .......................... 6E-79
5e. Vehicle Operates as Designed ............ 6E-80
6. Re-examine the complaint ..................... 6E-81
7. Repair and Verify Fix ............................. 6E-81
GENERAL SERVICE INFORMATION ....... 6E-82
ON-BOARD DIAGNOSTIC (OBD) ............. 6E-82
TECH 2 OPERATING FLOW CART
(START UP) ............................................. 6E-86
TYPICAL SCAN DATA & DEFINITIONS
(ENGINE DATA) ................................... 6E-88
TYPICAL SCAN DATA & DEFINITIONS
(ENGINE DATA) ................................... 6E-90
MISCELLANEOUS TEST .......................... 6E-92
Plotting Snapshot Graph ............................ 6E-93
Plotting Graph Flow Chart (Plotting graph
after obtaining vehicle information) .......... 6E-94
Flow Chart for Snapshot Replay
(Plotting Graph) ....................................... 6E-95
SNAPSHOT DISPLAY WITH TIS2000 ...... 6E-96
ON-BOARD DIAGNOSTIC (OBD) SYSTEM
CHECK .................................................... 6E-105
Circuit Description ...................................... 6E-105
Diagnostic Aids .......................................... 6E-105
Test Description ......................................... 6E-105
Page 1415 of 4264
4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–43
RELAY AND FUSE
RELAY A ND FUSE BOX LOCATION (LHD & RHD)
LHD
RHD
Page 1416 of 4264

6E–44 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
RELAY A ND FUSE BOX LOCATION (LHD & RHD)
RELAY & FUSE BOX
RELAY
No .RELAY
(4JA1-TC/4JH1-TC)
X -1 RELAY; TAIL LIGHT
X -2 RELAY; FRT F OG LI GHT
X -3 RELAY; HORN
X -4 RELAY; DIMMER
X -5 RELAY; GLOW
X -6 RELAY; COND, FAN
X -7 RELAY; RR FOG
X -8 RELAY; STARTER
X -9 SHORT CONNECTOR
(with Co oler) (LHD)
RELAY; HAZARD-RH (RHD)
X-10 SHORT CONNECTOR
(with Co oler) (LHD)
RELAY; HAZARD-LH (RHD)
X -11 RELAY; HEATER
X-12 RELAY; HEAD LIGHT
X-13 RELAY; ECM MAIN
X-14 RELAY; A/C COMP
X-15 RELAY; THERMO
FUSE
SLOW BLOW FUSE
NO.FUSE
(4JA1-TC/4JH1-TC)
EB-1 10A ECM
EB-2 10A RR FOG
EB-3 15A FRT FOG
EB-4 —
EB-5 10A ILLUMI & TAIL-RH
EB-6 10A TAIL-LH
EB-7 10A H/LIGHT RH-LOW
EB-8 10A H/LIGHT LH-LOW
EB-9 10A TRA ILER
EB-10 10A AC G (S)
EB-11 10A H/LIGHT RH-HIGH
EB-12 10A H/LIGHT LH-HIGH
EB-13 10A A/C
EB-14 10A 4WD
EB-15 10A HORN
EB-16 10A HAZARD
NO.SLOW BLOW FUSE
4JA1-TC/4JH1-TC
SBF-1 80A MAIN
SBF-2 20A COND, FAN
SBF-3 50A GLOW
SBF-4 30A ECM
SBF-5 40A IG 1
SBF-6 40A ABS-1
SBF-7 30A ABS-2
SBF-8 30A BLOWER
SBF-9 50A IG 2
Page 1417 of 4264
4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–45
FUSE A ND RELAY LOCATION (LHD & RHD)
FUSE
SLOW BLOW FUSE
RELAYNo. Capacity Indication on label No. Capacity Indication on label
1——12 15A CIGER
2 10A ABS 13 15A AUDIO (+B)
3——14 20A DOOR LOCK
4 15A BACK UP 15 10A METER (+B)
5 15A METER 16 10A ROOM
6 10A TURN 17 10A ANTI THEFT
7 15A ELEC.IG 18 15A STOP
8 15A ENGINE 19 15A ACC SOCKET
9 20A FRT WIPER 20 10A STARTER
10 15A EGR 21 10A SRS
11 10A AUDIO
No. Capacity Indication on label
SBF-10 20A RR DEF
SBF-11 30A POWER WINDOW
Connector No. B-7 B-8 B-40
4JA1-TC, 4JH1-TC REAR
DEFOGGERPOWER
WINDOWACC
SOCKET
FUSE BOX
Page 1449 of 4264

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–77
Diagnostic Thought Process
As you follow a diagnostic plan, every box on the
Strategy Based Diagnostics chart requires you to use
the diagnostic thought process. This method of thinking
optimizes your diagnosis in the following ways:
Improves your understanding and definition of the
customer complaint
Saves time by avoiding testing and/or replacing good
parts
Allows you to look at the problem from different
perspectives
Guides you to determine what level of understanding
about system operation is needed:
–Owner’s manual level
–Service manual level
–In-depth (engineering) level
–Owner’s manual level
–Service manual level
–In-depth (engineering) level
1. Verify the Complaint
What you should do
To verify the customer complaint, you need to know the
correct (normal) operating behavior of the system and
verify that the customer complaint is a valid failure of the
system.
The following information will help you verify the
complaint:
WHAT the vehicle model/options are
WHAT aftermarket and dealer-installed accessories
exist
WHAT related system(s) operate properly
WHEN the problem occurs
WHERE the problem occurs
HOW the problem occurs
HOW LONG the condition has ex isted (and if the
system ever worked correctly)
HOW OFTEN the problem occurs
Whether the severity of the problem has increased,
decreased or stayed the same
What resources you should use
Whenever possible, you should use the following
resources to assist you in verifying the complaint:
Service manual Theory or Circuit Description
sections
Service manual “System Performance Check”
Owner manual operational description
Technician ex perience
Identical vehicle for comparisonCircuit testing tools
Vehicle road tests
Complaint check sheet
Contact with the customer
2. Perform Preliminary Checks
NOTE: An estimated 10 percent of successful vehicle
repairs are diagnosed with this step!
What you should do
You perform preliminary checks for several reasons:
To detect if the cause of the complaint is VISUALLY
OBVIOUS
To identify parts of the system that work correctly
To accumulate enough data to correctly and
accurately search for a ISUZU Service Bulletin on
ISUZU Web site.
The initial checks may vary depending on the
complex ity of the system and may include the following
actions:
Operate the suspect system
Make a visual inspection of harness routing and
accessible/visible power and ground circuits
Check for blown fuses
Make a visual inspection for separated connectors
Make a visual inspection of connectors (includes
checking terminals for damage and tightness)
Check for any DTCs stored by the on-board
computers
Sense unusual noises, smells, vibrations or
mov ements
Investigate the vehicle service history (call other
dealerships, if appropriate)
What resources you should use
Whenever appropriate, you should use the following
resources for assistance in performing preliminary
checks:
Tech II or other technical equipment for viewing DTCs
Service manual information:
–Component locations
–Harness routing
–Wiring schematics
–Procedures for viewing DTCs
Dealership service history file
Vehicle road test
Identical vehicle or system for comparison