6C–1
ENGINE FUEL
ENGINE
ENGINE FUEL
CONTENTS
Service Precaution 6C–1. . . . . . . . . . . . . . . . . . . . . .
General Description 6C–2. . . . . . . . . . . . . . . . . . . . .
Fuel Metering 6C–3. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter 6C–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter and Associated Parts 6C–4. . . . . . . . .
Removal 6C–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 6C–4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C–5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 6C–5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
In–Tank Fuel Filter 6C–5. . . . . . . . . . . . . . . . . . . . .
Fuel Pump Flow Test 6C–5. . . . . . . . . . . . . . . . . . .
Fuel Pump 6C–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump and Associated Parts 6C–6. . . . . . . .
Removal 6C–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C–6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump Relay 6C–7. . . . . . . . . . . . . . . . . . . . . . . .
General Description 6C–7. . . . . . . . . . . . . . . . . . . . .
Fuel Tank 6C–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel Tank and Associated Parts 6C–7. . . . . . . . .
Removal 6C–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C–8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Tube / Quick – Connect Fittings 6C–8. . . . . . .
Precautions 6C–8. . . . . . . . . . . . . . . . . . . . . . . . . . .
Cautions During Work 6C–8. . . . . . . . . . . . . . . . . .
Removal 6C–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reuse of Quick–Connector 6C–10. . . . . . . . . . . . . . .
Assembling Advice 6C–10. . . . . . . . . . . . . . . . . . . . . .
Fuel Gauge Unit 6C–11. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Gauge Unit and Associated Parts 6C–11. . .
Removal 6C–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C–11. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filler Cap 6C–12. . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 6C–12. . . . . . . . . . . . . . . . . . . . .
Inspection 6C–12. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 6C–12. . . . . . . . . . . . .
Service Precaution
WARNING: IF SO EQUIPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.
6C–2
ENGINE FUEL
General Description
140RW030
Legend
(1) Fuel Filler Cap
(2) Fuel Tank
(3) Rollover Valve
(4) Fuel Pump
(5) Fuel Filter
(6) Fuel Rail Right
(7) Right Bank(8) Fuel Rail Left
(9) Left Bank
(10) Fuel Pressure Control Valve
(11) Common Chamber
(12) Duty Solenoid Valve
(13) Throttle Valve
(14) Canister
When working on the fuel system, there are several
things to keep in mind:
Any time the fuel system is being worked on,
disconnect the negative battery cable except for
those tests where battery voltage is required.
Always keep a dry chemical (Class B) fire
extinguisher near the work area.
Replace all pipes with the same pipe and fittings that
were removed.
Clean and inspect “O” rings. Replace if required.
Always relieve the line pressure before servicing any
fuel system components.
Do not attempt repairs on the fuel system until you
have read the instructions and checked the pictures
relating to that repair.
6C–4
ENGINE FUEL
Fuel Filter
Fuel Filter and Associated Parts
041RW014
Legend
(1) Fuel Filler Cap
(2) Fuel Hose(3) Fuel Filter Fixing Bolt
(4) Fuel Filter
Removal
CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system
for loose connection or leakage. For the fuel system
diagnosis, see Section “Driveability and Emission”.
1. Disconnect battery ground cable.
2. Remove Fuel filler cap(1).
3. Disconnect fuel hoses(2) from fuel filter on both
engine side and fuel tank side.
4. Fuel filter fixing bolt(3).
Remove the fuel filter fixing bolt(3) on fuel filter
holder.
5. Remove fuel filter(4).
Inspection
1. Replace the fuel filter if the fuel leaks from fuel filter
body or if the fuel filter body itself is damaged.
2. Replace the filter if it is clogged with dirt or sediment.
3. Check the drain of receive rubber and if it is clogged
with dust, clean it up with air.
6E–3 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0351
Ignition 1 Control Circuit 6E–206. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0352
Ignition 2 Control Circuit 6E–209. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0353
Ignition 3 Control Circuit 6E–212. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0354
Ignition 4 Control Circuit 6E–215. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0355
Ignition 5 Control Circuit 6E–218. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0356
Ignition 6 Control Circuit 6E–221. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0402
EGR Pintle Crank Error 6E–224. . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0404
EGR Open Stuck 6E–226. . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0405
EGR Low Voltage 6E–228. . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0406
EGR High Voltage 6E–231. . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0502
VSS Circuit Low Input 6E–234. . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0562
System Voltage Low 6E–237. . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0563
System Voltage High 6E–239. . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0601
PCM Memory 6E–240. . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1154
HO2S Circuit Transition Time Ratio Bank 2
Sensor 1 6E–241. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1171
Fuel System Lean During Acceleration 6E–245. . . .
Diagnostic Trouble Code (DTC) P1380
ABS Rough Road ABS System Fault 6E–248. . . . . .
Diagnostic Trouble Code (DTC) P1404
EGR Closed Stuck 6E–249. . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1508
IAC System Low RPM 6E–251. . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1509
IAC System High RPM 6E–254. . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1618
Serial Peripheral Interface (SPI) PCM
Interprocessor Communication Error 6E–257. . . . . .
Diagnostic Trouble Code (DTC) P1625
PCM Unexpected Reset 6E–258. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1640
Driver-1-Input High Voltage 6E–259. . . . . . . . . . . . . .
Symptom Diagnosis 6E–262. . . . . . . . . . . . . . . . . . . . .
Default Matrix Table 6E–288. . . . . . . . . . . . . . . . . . . . .
Camshaft Position (CMP) Sensor 6E–291. . . . . . . . . .
Crankshaft Position (CKP) Sensor 6E–292. . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 6E–292.
Heated Oxygen Sensor (HO2S) 6E–293. . . . . . . . . . .
Intake Air Temperature (IAT) Sensor 6E–295. . . . . . .
Knock Sensor (KS) 6E–296. . . . . . . . . . . . . . . . . . . . . . Mass Air Flow (MAF) Sensor 6E–297. . . . . . . . . . . . .
Manifold Absolute Pressure (MAP) Sensor 6E–297.
Malfunction Indicator Lamp (MIL) 6E–298. . . . . . . . . .
Powertrain Control Module (PCM) 6E–298. . . . . . . . .
EEPROM 6E–300. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Steering Pressure (PSP) Switch 6E–300
. . . .
Throttle Position (TP) Sensor 6E–301. . . . . . . . . . . . .
Vehicle Speed Sensor (VSS) 6E–302. . . . . . . . . . . . .
Air Cleaner/Air Filter 6E–303. . . . . . . . . . . . . . . . . . . . .
Idle Air Control (IAC) Valve 6E–304. . . . . . . . . . . . . . .
Common Chamber 6E–305. . . . . . . . . . . . . . . . . . . . . .
Accelerator Cable Assembly 6E–305. . . . . . . . . . . . . .
Accelerator Pedal Replacement 6E–308. . . . . . . . . . .
Fuel Filter Cap 6E–310. . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter 6E–310. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Gauge Unit 6E–313. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Injectors 6E–314. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pressure Regulator 6E–315. . . . . . . . . . . . . . . . .
Fuel Metering System 6E–317. . . . . . . . . . . . . . . . . . . .
Fuel Pump Assembly 6E–318. . . . . . . . . . . . . . . . . . . .
Fuel Pump Relay 6E–319. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Rail Assembly 6E–319. . . . . . . . . . . . . . . . . . . . . .
Fuel Tank 6E–321. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Body (TB) 6E–323. . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition System 6E–324. . . . . . . . . . . . . . . .
Catalytic Converter 6E–325. . . . . . . . . . . . . . . . . . . . . .
Air Conditioning Relay 6E–325. . . . . . . . . . . . . . . . . . .
EVAP Canister Hoses 6E–326. . . . . . . . . . . . . . . . . . . .
EVAP Canister 6E–326. . . . . . . . . . . . . . . . . . . . . . . . . .
EVAP Canister Purge Solenoid 6E–327. . . . . . . . . . . .
Fuel Tank Vent Valve 6E–328. . . . . . . . . . . . . . . . . . . .
Linear Exhaust Gas Recirculation
(EGR) Valve 6E–328. . . . . . . . . . . . . . . . . . . . . . . . . . .
Positive Crankcase Ventilation (PCV) Valve 6E–329.
Wiring and Connectors 6E–330. . . . . . . . . . . . . . . . . . .
PCM Connectors and Terminals 6E–330. . . . . . . . . . .
Wire Harness Repair: Twisted Shielded
Cable 6E–330. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Twisted Leads 6E–331. . . . . . . . . . . . . . . . . . . . . . . . . .
Weather-Pack Connector 6E–332. . . . . . . . . . . . . . . . .
Com-Pack III 6E–333. . . . . . . . . . . . . . . . . . . . . . . . . . .
Metri-Pack 6E–333. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 6E–335. . . . . . . . . . . . . . . . . . . . .
General Description (PCM and Sensors) 6E–335. . .
58X Reference PCM Input 6E–335. . . . . . . . . . . . . .
A/C Request Signal 6E–335. . . . . . . . . . . . . . . . . . . .
Crankshaft Position (CKP) Sensor 6E–335. . . . . . .
Camshaft Position (CMP) Sensor and
Signal 6E–335. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 6E–335
Electrically Erasable Programmable Read
Only Memory (EEPROM) 6E–336. . . . . . . . . . . . . .
Fuel Control Heated Oxygen Sensors 6E–336. . . .
Intake Air Temperature (IAT) Sensor 6E–336. . . . .
6E–29 ENGINE DRIVEABILITY AND EMISSIONS
Engine Component Locator Table
Number
NameLocation
1Linear Exhaust Gas Recirculation (EGR) ValveRear right side of the engine
2Throttle Position (TP) SensorOn the rear of the throttle body
3Intake Air Temperature (IAT) SensorOn the intake air duct near the throttle body
4Check Engine (MIL) LightOn the instrument panel beneath the
tachometer
5Positive Crankcase Ventilation (PCV) ValveOn the left of the cylinder head cover
6Air CleanerLeft front of the engine bay
7Mass Air Flow (MAF) SensorAttached to the air filter box
8Camshaft Position (CMP) SensorOn the rear right side at the left of the cylinder
head cover
9Fuel Pressure RegulatorRear right side of the engine
10Idle Air Control (IAC) ValveOn the left of the throttle body
11Upper Intake ManifoldTop of the engine
12Fuse/Relay BoxAlong the inside of the right fender
13Manifold Absolute Pressure (MAP) SensorBolted to the top of the upper intake manifold
14Throttle BodyBetween the intake air duct and the upper
intake manifold
15Engine Coolant Temperature SensorOn the coolant crossover pipe at the front of
the engine, near the throttle body
6E–31 ENGINE DRIVEABILITY AND EMISSIONS
Engine Component Locator Table
Number
NameLocation
1Linear Exhaust Gas Recirculation (EGR) ValveRear right side of the engine
2Throttle Position (TP) SensorOn the rear of the throttle body
3Intake Air Temperature (IAT) SensorOn the intake air duct near the throttle body
4Check Engine (MIL) LightOn the instrument panel beneath the
tachometer
5Positive Crankcase Ventilation (PCV) ValveOn the left of the cylinder head cover
6Air CleanerLeft front of the engine bay
7Mass Air Flow (MAF) SensorAttached to the air filter box
8Camshaft Position (CMP) SensorOn the rear right side at the left of the cylinder
head cover
9Fuel Pressure RegulatorRear right side of the engine
10Idle Air Control (IAC) ValveOn the left of the throttle body
11Upper Intake ManifoldTop of the engine
12Fuse/Relay BoxAlong the inside of the right fender
13Manifold Absolute Pressure (MAP) SensorBolted to the top of the upper intake manifold
14Throttle BodyBetween the intake air duct and the upper
intake manifold
15Engine Coolant Temperature SensorOn the coolant crossover pipe at the front of
the engine, near the throttle body
6E–38
ENGINE DRIVEABILITY AND EMISSIONS
General Service Information
OBD Serviceablity Issues
The list of non-vehicle faults that could affect the
performance of the OBD system has been compiled.
These non-vehicle faults vary from environmental
conditions to the quality of fuel used.
The illumination of the MIL (“Check Engine” lamp) due to
a non-vehicle fault could lead to misdiagnosis of the
vehicle, increased warranty expense and customer
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Using fuel with the wrong octane rating for your vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using “premium” gasoline will
improve the performance of your vehicle. Most premium
fuels use alcohol to increase the octane rating of the fuel.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel’s ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Something as simple as a
high-performance exhaust system that affects exhaust
system back pressure could potentially interfere with the
operation of the EGR valve and thereby turn on the MIL
(“Check Engine” lamp). Small leaks in the exhaust
system near the post catalyst oxygen sensor can also
cause the MIL (“Check Engine” lamp) to turn on.
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL (“Check
Engine” lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain-soaked, it can temporarily
cause engine misfire and turn on the MIL (“Check Engine”
lamp).
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(“Check Engine” lamp) to turn on if the vehicle is not
maintained properly. Restricted air filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a “non-vehicle
fault”, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.Related System Faults
Many of the OBD system diagnostics will not run if the
PCM detects a fault on a related system or component.
One example would be that if the PCM detected a Misfire
fault, the diagnostics on the catalytic converter would be
suspended until Misfire fault was repaired. If the Misfire
fault was severe enough, the catalytic converter could be
damaged due to overheating and would never set a
Catalyst DTC until the Misfire fault was repaired and the
Catalyst diagnostic was allowed to run to completion. If
this happens, the customer may have to make two trips to
the dealership in order to repair the vehicle.
Maintenance Schedule
Refer to the Maintenance Schedule.
Visual / Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:
Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.
Inspect hoses that are difficult to see behind other
components.
Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the “Class II” communication system.
Each bit of information can have one of two lengths: long
or short. This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire. The messages carried on Class II data streams are
also prioritized. If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue. The device
with the lower priority message must wait. The most
significant result of this regulation is that it provides Tech 2
manufacturers with the capability to access data from any
make or model vehicle that is sold.
6E–80
ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
The electronic Ignition system uses a coil-at-plug method
of spark distribution. In this type of ignition system, the
powertrain control module (PCM) triggers the correct
driver inside the ignition coil, which then triggers the
correct ignition coil based on the 58X signal received from
the crankshaft position sensor (CKP). The spark plug
connected to the coil fires when the ICM opens the ground
circuit for the coil’s primary circuit.
During crank, the PCM monitors the CKP 58X signal. The
CKP signal is used to determine which cylinder will fire
first. After the CKP 58X signal has been processed by the
PCM, it will command all six injectors to allow a priming
shot of fuel for all the cylinders. After the priming, the
injectors are left “OFF” during the next six 58X reference
pulses from the CKP. This allows each cylinder a chance
to use the fuel from the priming shot. During this waiting
period, a camshaft position (CMP) signal pulse will have
been received by the PCM. The CMP signal allows the
PCM to operate the injectors sequentially based on
camshaft position. If the camshaft position signal is not
present at start-up, the PCM will begin sequential fuel
delivery with a 1-in-6 chance that fuel delivery is correct.
The engine will run without a CMP signal, but will set a
DTC code.
Diagnostic Aids
An intermittent problem may be caused by a poor
connection, rubbed-through wire insulation or a wire
broken inside the insulation. Check for the following
items:
Poor connection or damaged harness – Inspect the
PCM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.
Faulty engine coolant temperature sensor – Using
Tech 2, compare engine coolant temperature with
intake air temperature on a completely cool engine.
Engine coolant temperature should be within 10
C of
intake air temperature. If not, replace the ECT sensor.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
5. An obvious cause of low fuel pressure would be an
empty fuel tank.
6. The engine will easily start and run if a few injectors
are disabled. It is not necessary to test all injectors
at this time since this step is only a test to verify that
all of the injectors have not been disabled by fuel
contamination.
7. A blinking test light verifies that the PCM is
monitoring the 58X crankshaft reference signal and
is capable of activating the injectors. If there is an
open or shorted driver circuit, DTCs 201-206 should
be set.
19.By using a spark tester, each ignition coil’s ability to
produce 25,000 volts is verified.
25.If there is an open or shorted driver circuit, DTCs
201-206 should be set. All six injector driver circuits
can be checked at one time without removing the
intake manifold if a 5-8840-2636-0 test light is
available. This is the alternative procedure:
With the ignition “OFF,” disconnect the gray
connector located at the rear of the air filter, attached
to a bracket on the purge canister.
Connect test light 5-8840-2636-0 to the connector.
Do any of the light constantly illuminate or fail to blink
when the engine is cranked? If so, repair the short or
open circuit, or replace the PCM if indicated.
This procedure only tests the driver circuit as far as the
test connection, so step 31 is added to test the circuit all
the way to the injector.