3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-1
ENGINE
3.5L ENGINE DRIVEABILITY AND EMISSIONS
CONTENTS
ABBREVIATION CHARTS ................................ 6E-5
COMPONENT LOCATOR ................................. 6E-6
ENGINE COMPONENT LOCATOR TABLE .. 6E-6
ECM CIRCUIT DIAGRAM ................................. 6E-10
GROUND POINT CHART G.EXP (LHD)
WITHOUT EUROPE, ISRAEL, TURKEY (1/4). 6E-13
GROUND POINT CHART G.EXP (LHD) (2/4) .. 6E-14
GROUND POINT CHART G.EXP (LHD) (3/4) .. 6E-15
GROUND POINT CHART G.EXP (LHD) (4/4) .. 6E-16
GROUND POINT CHART G.EXP (RHD) (1/4) . 6E-17
GROUND POINT CHART G.EXP (RHD) (2/4) . 6E-18
GROUND POINT CHART G.EXP (RHD) (3/4) . 6E-19
GROUND POINT CHART G.EXP (RHD) (4/4) . 6E-20
LOCATION ........................................................ 6E-21
CABLE HARNESS & CONNECTOR
LOCATION ....................................................... 6E-22
CONNECTOR LIST ........................................... 6E-27
RELAY AND FUSE ............................................ 6E-30
RELAY AND FUSE BOX LOCATION
(LHD&RHD) ................................................... 6E-30
RELAY AND FUSE BOX LOCATION
(LHD&RHD) ................................................... 6E-31
FUSE AND RELAY LOCATION
(LHD&RHD) ................................................... 6E-32
ECM WIRING DIAGRAM (1/10) ........................ 6E-33
ECM WIRING DIAGRAM (2/10) ........................ 6E-34
ECM WIRING DIAGRAM (3/10) ........................ 6E-35
ECM WIRING DIAGRAM (4/10) ........................ 6E-36
ECM WIRING DIAGRAM (5/10) ........................ 6E-37
ECM WIRING DIAGRAM (6/10) ........................ 6E-38
ECM WIRING DIAGRAM (7/10) ........................ 6E-39
ECM WIRING DIAGRAM (8/10) ........................ 6E-40
ECM WIRING DIAGRAM (9/10) ........................ 6E-41
ECM WIRING DIAGRAM (10/10) ...................... 6E-42
ECM CONNECTOR PIN ASSIGNMENT
& OUTPUT SIGNAL ......................................... 6E-43
GENERAL DESCRIPTION FOR ECM AND
SENSORS ........................................................ 6E-51
Mass Air Flow (MAF) Sensor & Intake Air
Temperature (IAT) Sensor ............................. 6E-52
Throttle Position Sensor (TPS)....................... 6E-52
Idle Air Control (IAC) Valve ............................ 6E-53
Camshaft Position (CMP) Sensor .................. 6E-53
Crankshaft Position (CKP) Sensor ................. 6E-54
Engine Coolant Temperature (ECT) Sensor .. 6E-54
Vehicle Speed Sensor (VSS) ......................... 6E-55
Heated Oxygen (O
2) Sensor........................... 6E-55
GENERAL DESCRIPTION FOR FUEL
METERING....................................................... 6E-56
GENERAL DESCRIPTION FOR ELECTRONIC
IGNITION SYSTEM IGNITION
COILS & CONTROL ......................................... 6E-58
GENERAL DESCRIPTION FOR EVAPORATIVE
EMISSION SYSTEM ........................................ 6E-61
GENERAL DESCRIPRION FOR EXHAUST
GAS RECIRCULATION (EGR) SYSTEM......... 6E-62
ISUZU STRATEGY BASED DIAGNOSTICS .... 6E-63
Diagnostic Thought Process .......................... 6E-64
1. Verify the Complaint ................................... 6E-64
2. Perform Preliminary Checks....................... 6E-64
3. Check Bulletins and Troubleshooting
Hints ........................................................... 6E-65
4. Perform Service Manual Diagnostic
Checks ....................................................... 6E-65
5a and 5b. Perform Service Manual
Diagnostic Procedures ............................... 6E-65
5c. Technician Self Diagnoses ....................... 6E-65
5d. Intermittent Diagnosis............................ 6E-66
Symptom Simulation Tests.......................... 6E-67
5e. Vehicle Operates as Designed ................. 6E-68
6. Re-Examine the Complaint ........................ 6E-68
7. Repair and Verify Fix .................................. 6E-68
GENERAL SERVICE INFORMATION .............. 6E-69
Aftermarket Electrical and Vacuum
Equipment ..................................................... 6E-69
Electrostatic Discharge Damage .................... 6E-69
6E-30 3.5L ENGINE DRIVEABILITY AND EMISSIONS
RELAY AND FUSE
RELAY AND FUSE BOX LOCATION (LHD & RHD)
LHD
RHD
RTW48ALF000201 & 825R300008
3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-31
RELAY AND FUSE BOX LOCATION (LHD & RHD)
RELAY & FUSE BOX
RELAY
NO. Relay name
X-1 RELAY; TAIL LIGHT
X-2 RELAY; FUEL PUMP
X-3 RELAY; HORN
X-4 RELAY; DIMMER
X-5 RELAY; FOG LIGHT
X-6 RELAY; STARTER
X-7 RELAY; COND, FAN
X-8 RELAY;
X-9 RELAY; HAZARD-RH
X-10 RELAY; HAZARD-LH
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
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SLOW BLOW FUSE
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6E-32 3.5L ENGINE DRIVEABILITY AND EMISSIONS
FUSE & RELAY LOCATION (LHD & RHD)
RTW46EMF001001
FUSE
/
0123 410
21,,+
5+
/
0123 410
21,,+
5+
(6
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# $ 7
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SLOW BLOW FUSE
/
0123 410
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RELAY
Connector No. B-7 B-8 B-40
6VE1 REAR DEFOGGER POWER WINDOW ACC SOCKET
FUSE BOX
6E-64 3.5L ENGINE DRIVEABILITY AND EMISSIONS
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 o
f
understanding about system operation is needed:
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 o
f
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 existed (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 experience
Identical vehicle for comparison
Circuit 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.
The initial checks may vary depending on the
complexity 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 o
r
movements
Investigate the vehicle service history (call othe
r
dealerships, if appropriate)
What resources you should use
Whenever appropriate, you should use the following
resources for assistance in performing preliminary
checks:
Tech 2 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
ENGINE DRIVEABILITY AND EMISSIONS 6E–1
ENGINE
CONTENTS
C24SE ENGINE DRIVEABILITY AND EMISSIONS
ABBREVIATIONS CHARTS ......................... 6E-6
ECM Circuit Diagram (1/2) ............................ 6E-11
ECM Circuit Diagram (2/2) ............................ 6E-12
GROUND POINT CHART - LHD G.EXP (1/4) 6E-13
GROUND POINT CHART - RHD G.EXP (1/4) 6E-17
LOCATION ................................................... 6E-21
CABLE HARNESS & CONNECTOR
LOCATION .............................................. 6E-23
CABLE HARNESS & CONNECTOR
LOCATION LHD ................................... 6E-24
CABLE HARNESS & CONNECTOR
LOCATION RHD ................................... 6E-25
CONNECTOR LIST ...................................... 6E-28
RELAY AND FUSE ....................................... 6E-30
RELAY AND FUSE BOX LOCATION
(LHD & RHD) ........................................... 6E-30
FUSE AND RELAY LOCATION (LHD & RHD) 6E-32
ECM WIRING DIAGRAM (1/9) ..................... 6E-33
ECM WIRING DIAGRAM (2/9) ..................... 6E-34
ECM WIRING DIAGRAM (3/9) ..................... 6E-35
ECM WIRING DIAGRAM (4/9) ..................... 6E-36
ECM WIRING DIAGRAM (5/9) ..................... 6E-37
ECM WIRING DIAGRAM (6/9) ..................... 6E-38
ECM WIRING DIAGRAM (7/9) ..................... 6E-39
ECM WIRING DIAGRAM (8/9) ..................... 6E-40
ECM WIRING DIAGRAM (9/9) ..................... 6E-41
ECM CONNECTOR PIN ASSIGNMENT &
OUTPUT SIGNAL .................................... 6E-42
GENERAL DESCRIPTION FOR ECM AND
SENSORS ............................................... 6E-48
Engine Control Module (ECM) ................... 6E-48
Manifold Absolute Pressure (MAP) Sensor 6E-48
Throttle Position Sensor (TPS) .................. 6E-49
Idle Air Control (IAC) Valve ....................... 6E-49
Crankshaft Position (CKP) Sensor ............ 6E-50
Knock Sensor (KS) .................................... 6E-50
Engine Coolant Temperature (ECT) Sensor 6E-50
Intake Air Temperature (IAT) Sensor ........ 6E-51
Vehicle Speed Sensor (VSS) .................... 6E-51
Heated Ox ygen (O
2) Sensor ..................... 6E-51
GENERAL DESCRIPTION FOR FUEL
METERING .............................................. 6E-52Battery Voltage Correction Mode ............... 6E-52
Clear Flood Mode ...................................... 6E-52
Deceleration Fuel Cutoff (DFCO) Mode .... 6E-52
Engine Speed/ Vehicle Speed/ Fuel Disable
Mode ........................................................ 6E-52
Acceleration Mode ..................................... 6E-52
Fuel Cutoff Mode ....................................... 6E-52
Starting Mode ............................................ 6E-52
Run Mode .................................................. 6E-52
Fuel Metering System Components .......... 6E-53
Fuel Injector ............................................... 6E-53
Fuel Pressure Regulator ............................ 6E-53
Fuel Rail ..................................................... 6E-53
Fuel Pump Electrical Circuit ....................... 6E-53
Thottle Body Unit ....................................... 6E-53
GENERAL DESCRIPTION FOR ELECTRIC
IGNITION SYSTEM ................................. 6E-54
Spark Plug ................................................. 6E-54
GENERAL DESCRIPTION FOR EVAPORATIVE
EMISSION SYSTEM ............................... 6E-57
EVAP Emission Control System Purpose .. 6E-57
EVAP Emission Control System Operation 6E-57
System Fault Detection .............................. 6E-57
POSITIVE CRANKCASE VENTILATION (PCV)
SYSTEM .................................................. 6E-59
Crankcase Ventilation System Purpose .... 6E-59
A/C CLUTCH DIAGNOSIS ........................ 6E-60
A/C Clutch Circuit Operation ...................... 6E-60
A/C Clutch Circuit Purpose ........................ 6E-60
A/C Request Signal ................................... 6E-60
ISUZU STRATEGY BASED DIAGNOSTICS 6E-61
Overview .................................................... 6E-61
STRATEGY BASED DIAGNOSTICS CHART 6E-61
Diagnostic Thought Process ...................... 6E-62
1. Verify the Complaint .............................. 6E-62
2. Perform Preliminary Checks .................. 6E-62
3. Check Bulletins and Troubleshooting Hints 6E-63
4. Perform Service Manual Diagnostic Checks 6E-63
5a and 5b. Perform Service Manual Diagnostic
Procedures .............................................. 6E-63
5c. Technician Self Diagnoses .................. 6E-63
5d. Intermittent Diagnosis .......................... 6E-64
6E–30 ENGINE DRIVEABILITY AND EMISSIONS
RELAY AND FUSE
RELAY A ND FUSE BOX LOCATION (LHD & RHD)
LHD
RHD
ENGINE DRIVEABILITY AND EMISSIONS 6E–31
RELAY A ND FUSE BOX LOCATION (LHD & RHD)
RELAY & FUSE BOX
RELAY
No. Relay Name
X-1 RELAY; TAIL LIGHT
X-2 RELAY; FUEL PUMP
X-3 RELAY; HORN
X-4 RELAY; DIMMER
X-5 RELAY; FRT FOG
LIGHT (LHD only)
X-6 RELAY; STARTER
X-7 RELAY; COND, FAN
X-8—
X-9—
X-10—
X-11 RELAY; HEATER
X-12 RELAY; HEAD LIGHT
X-13—
X-14 RELAY; A/C COMP
X-15 RELAY; THERMO
FUSE
NO. Fuse Name
EB-1 15A ECM
EB-2—
EB-3 15A FRT FOG
EB-4 15A ACG (S)
EB-5 10A ILLUMI
EB-6 10A TAIL
EB-7 10A H/LIGHT-RH
10A H/LIGHT-RH-LOW
EB-8 10A H/LIGHT-LH
10A H/LIGHT-LH-LOW
(LHD only)
EB-9 20A FUEL PUMP
EB-10 10A O
2 SENSOR
EB-11 10A H/LIGHT-RH-
HIGH (LHD only)
EB-12 10A H/LIGHT-LH-
HIGH (LHD only)
EB-13 10A A/C
EB-14—
EB-15 10A HORN
EB-16 10A HAZARD
SLOW BLOW FUSE
NO. Slow Blow Fuse Name FUSE NO. Slow Blow Fuse Name
SBF-1 100A MAIN SBF-6—
SBF-2—SBF-7—
SBF-3—SBF-8 30A BLOWER
SBF-4 20A COND, FAN SBF-9 50A IG 2
SBF-5 40A IG 1