2004 ISUZU TF SERIES check oil

6E–64 ENGINE DRIVEABILITY AND EMISSIONS
–Are there areas subjected to vibration or
movement (engine, transmission or
suspension)?
–Are there areas ex posed to moisture, road salt
or other corrosives (battery acid, oil or other
fluids)?
–Are there common mounting areas with other
systems/components?
–Have previous repairs been performed to wiring,
connectors, components or mounting areas
(causing pinched wires between panels and
drivetrain or suspension components without
causing and immediate problem)?
–Does the vehicle have aftermarket or dealer-
installed equipment (radios, telephone, etc.)
Step 2: Isolate the problem
At this point, you should have a good idea of what could
cause the present condition, as well as could not cause
the condition. Actions to take include the following:
Divide (and separate, where possible) the system or
circuit into smaller sections
Confine the problem to a smaller area of the vehicle
(start with main harness connections while removing
panels and trim as necessary in order to eliminate
large vehicle sections from further investigation)
For two or more circuits that do not share a common
power or ground, concentrate on areas where
harnesses are routed together or connectors are
shared (refer to the following hints)
Hints
Though the symptoms may vary, basic electrical failures
are generally caused by:
Loose connections:
–Open/high resistance in terminals, splices,
connectors or grounds
Incorrect connector/harness routing (usually in new
vehicles or after a repair has been made):
–Open/high resistance in terminals, splices,
connectors of grounds
Corrosion and wire damage:
–Open/high resistance in terminals, splices,
connectors of grounds
Component failure:
–Opens/short and high resistance in relays,
modules, switches or loads
Aftermarket equipment affecting normal operation of
other systems
You may isolate circuits by:
Unplugging connectors or removing a fuse to
separate one part of the circuit from another part
Operating shared circuits and eliminating those that
function normally from the suspect circuit
If only one component fails to operate, begin testingat the component
If a number of components do no operate, begin tests
at the area of commonality (such as power sources,
ground circuits, switches or major connectors)
What resources you should use
Whenever appropriate, you should use the following
resources to assist in the diagnostic process:
Service manual
Technical equipment (for data analysis)
Ex perience
Technical Assistance
Circuit testing tools
5d. Intermittent Diagnosis
By definition, an intermittent problem is one that does
not occur continuously and will occur when certain
conditions are met. All these conditions, however, may
not be obvious or currently known. Generally,
intermittents are caused by:
Faulty electrical connections and wiring
Malfunctioning components (such as sticking relays,
solenoids, etc.)
EMI/RFI (Electromagnetic/radio frequency
interference)
Aftermarket equipment
Intermittent diagnosis requires careful analysis of
suspected systems to help prevent replacing good
parts. This may involve using creativity and ingenuity to
interpret customer complaints and simulating all
ex ternal and internal system conditions to duplicate the
problem.
What you should do
Step 1: A cquire information
A thorough and comprehensive customer check sheet
is critical to intermittent problem diagnosis. You should
require this, since it will dictate the diagnostic starting
point. The vehicle service history file is another
source for accumulating information about the
complaint.
Step 2: A nalyze the intermittent problem
Analyze the customer check sheet and service history
file to determine conditions relevant to the suspect
system(s).
Using service manual information, you must identify,
trace and locate all electrical circuits related to the
malfunctioning system(s). If there is more than one
system failure, you should identify, trace and locate
areas of commonality shared by the suspect circuits.

ENGINE DRIVEABILITY AND EMISSIONS 6E–67
GENERAL SERVICE INFORMATION
Aftermarket Electrical and Vacuum
Equipment
Aftermarket (add-on) electrical and vacuum equipment
is defined as any equipment which connects to the
vehicle's electrical or vacuum systems that is installed
on a vehicle after it leaves the factory. No allowances
have been made in the vehicle design for this type of
equipment.
NOTE: No add-on vacuum equipment should be added
to this vehicle.
NOTE: Add-on electrical equipment must only be
connected to the vehicle's electrical system at the
battery (power and ground).
Add-on electrical equipment, even when installed to
these guidelines, may still cause the electric system to
malfunction. This may also include equipment not
connected to the vehicle electrical system such as
portable telephones and radios. Therefore, the first step
in diagnosing any electric problem is to eliminate all
aftermarket electrical equipment from the vehicle. After
this is done, if the problem still ex ists, it may be
diagnosed in the normal manner.
Electrostatic Discharge Damage
Electronic components used in the ECM are often
designed to carry very low voltage. Electronic
components are susceptible to damage caused by
electrostatic discharge. Less than 100 volts of static
electricity can cause damage to some electronic
components. By comparison, it takes as much as 4000
volts for a person to feel even the zap of a static
discharge.
There are several ways for a person to become
statically charged. The most common methods of
charging are by friction and induction.
An ex ample of charging by friction is a person sliding
across a vehicle seat.
Charge by induction occurs when a person with well-
insulated shoes stands near a highly charged object
and momentarily touches ground. Charges of the
same polarity are drained off leaving the person
highly charged with the opposite polarity. Static
charges can cause damage, therefore it is important
to use care when handling and testing electronic
components.Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Accordingly, if commercially sold
sensor or switch is installed, it makes a wrong diagnosis
and turns on the check engine lamp.
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 check
engine lamp.
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the check
engine lamp to turn on if the vehicle is not maintained
properly. Restricted oil 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
follow ed.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
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
effectively use this section of the Service Manual.

6E–98 ENGINE DRIVEABILITY AND EMISSIONS
FUEL METERING SYSTEM CHECK
Some failures of the fuel metering system will result in
an “Engine Cranks But Will Not Run” symptom. If this
condition ex ists, refer to the Cranks But Will Not Run
chart. This chart will determine if the problem is caused
by the ignition system, the ECM, or the fuel pump
electrical circuit.
Refer to Fuel System Electrical Test for the fuel system
wiring schematic.
If there is a fuel delivery problem, refer to Fuel System
Diagnosis, which diagnoses the fuel injectors, the fuel
pressure regulator, and the fuel pump.
Followings are applicable to the vehicles with
closed Loop System:
If a malfunction occurs in the fuel metering system, it
usually results in either a rich HO2S signal or a lean
HO2S signal. This condition is indicated by the HO2S
voltage, which causes the ECM to change the fuel
calculation (fuel injector pulse width) based on the
HO2S reading. Changes made to the fuel calculation
will be indicated by a change in the long term fuel trim
values which can be monitored with a Scan Tool. Ideal
long term fuel trim values are around 0%; for a lean
HO2S signal, the ECM will add fuel, resulting in a fuel
trim value above 0%. Some variations in fuel trim values
are normal because all engines are not ex actly the
same. If the evaporative emission canister purge is 02
status may be rich condition. 02 status indicates the
lean condition, refer to DTC P1171 for items which can
cause a lean HO2S signal.
FUEL INJECTOR COIL TEST PROCEDURE
AND FUEL INJECTOR BALANCE TEST
PROCEDURE
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Relieve the fuel pressure by connecting 5-8840-
0378-0 T-Joint to the fuel pressure connection on the
fuel rail.
Caution: In order to reduce the risk of fire and
personal injury, wrap a shop towel around the
fuel pressure connection. The towel will absorb
any fuel leakage that occurs during the
connection of the fuel pressure gauge. Place the
towel in an approved container when the
connection of the fuel pressure gauge is
complete.
Place the fuel pressure gauge bleed hose in an
approved gasoline container.
With the ignition switch OFF open the valve on the
fuel pressure gauge.
3. Record the lowest voltage displayed by the DVM
after the first second of the test. (During the first
second, voltage displayed by the DVM may be
inaccurate due to the initial current surge.)
Injector Specifications:
The voltage displayed by the DVM should be
within the specified range.
The voltage displayed by the DVM may increase
throughout the test as the fuel injector windings
warm and the resistance of the fuel injector
windings changes.Resistance OhmsVoltage Specification at
10°C-35°C (50°F-95°F)
11.8-12.6 5.7-6.6

ENGINE DRIVEABILITY AND EMISSIONS 6E–99
An erratic voltage reading (large fluctuations in
voltage that do not stabilize) indicates an
intermittent connection within the fuel injector.
5. Injector Specifications:7. The Fuel Injector Balance Test portion of this chart
(Step 7 through Step 11) checks the mechanical (fuel
delivery) portion of the fuel injector. An engine
cooldown period of 10 minutes is necessary in order
to avoid irregular fuel pressure readings due to “Hot
Soak” fuel boiling.
Injector Coil Test Procedure (Steps 1-6) and Injector Balance Test Procedure (Steps 7-11)
NOTE: These figures are ex amples only.Highest Acceptable Voltage
Reading Above/Below
35°C/10°C (95°F/50°F)Acceptable
Subtracted Value
9.5Volts 0.6Volt
CYLINDER
1234
1st Reading (1) 296kPa
(43psi)296kPa
(43psi)296kPa
(43psi)296kPa
(43psi)
2nd Reading (2) 205kPa
(29psi)205kPa
(29psi)196kPa
(28psi)274kPa
(39psi)
Amount of Drop
(1st Reading-2nd Reading)91kPa
(14psi)91kPa
(14psi)100kPa
(15psi)22kPa
(4psi)
Av. Drop = 166kPa/24psi

10kPa/1.5psi
= 156 - 176kPa or
22.5 - 25.5psiFaulty, Lean
(Too Little Fuel
Drop)Faulty, Lean
(Too Little Fuel
Drop)Faulty, Lean
(Too Little Fuel
Drop)Faulty, Lean
(Too Little Fuel
Drop)

6E–100 ENGINE DRIVEABILITY AND EMISSIONS
Injector Coil Test Procedure (Steps 1-6) and Injector Balance Test Procedure (Steps 7-11)
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?—Go to Step 2Go to OBD
System Check
2 1. Turn the engine OFF.
NOTE: In order to prevent flooding of a single cylinder
and possible engine damage, relieve the fuel pressure
before performing the fuel injector coil test procedure.
2. Relieve the fuel pressure. Refer to Test
Description Number 2.
3. Connect the 5-8840-2618-0 Fuel Injector Tester to
B+ and ground, and to the 5-8840-2589-0 Injector
Adapter Cable.
4. Remove the harness connector of the Fuel
Injector and connect the 5-8840-2589-0 Injector
Adapter Cable for F/I check.
5. Set the amperage supply selector switch on the
fuel injector tester to the “Coil Test” 0.5 amp
position.
6. Connect the leads from the 5-8840-2392-0 Digital
Voltmeter (DVM) to the fuel injector tester. Refer
to the illustrations associated with the test
description.
7. Set the DVM to the tenths scale (0.0).
8. Observe the engine coolant temperature.
Is the engine coolant temperature within the specified
values?10°C (50°F)
to
35°C (95°F) Go to Step 3Go to Step 5
3 1. Set the injector adapter cable to injector #1.
2. Press the “Push to Start Test” button on the fuel
injector tester.
3. Observe the voltage reading on the DVM.
Important: The voltage reading may rise during the
test.
4. Record the lowest voltage observed after the first
second of the test.
5. Set the injector adapter cable to the nex t injector
and repeat steps 2, 3, and 4.
Did any fuel injector have an erratic voltage reading
(large fluctuations in voltage that did not stabilize) or a
voltage reading outside of the specified values? 5.7-6.6V Go to Step 4Go to Step 7
4 Replace the faulty fuel injector(S). Refer to Fuel
Injector.
Is the action complete?—Go to Step 7—

6E–104 ENGINE DRIVEABILITY AND EMISSIONS
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood
relay center.
3. Start the engine and alow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Pressure Gauge Installation
1. Remove the fuel pressure fitting cap.
2. Install fuel pressure gauge 5-8840-0378-0 to the
fuel feed line located in front of and above the right
side valve cover.
3. Reinstall the fuel pump relay.
Fuel System Electrical Test
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Using the Tech 2, ignition “On” and engine “On”.
2. Select the “Miscellaneous Test” and perform the
“Fuel Pump Relay” in the “Relays”.
3. Operate the Tech 2 in accordance with procedure.
Was the fuel pump operated, when the Tech 2 is
operated?—Go to Fuel
System
DiagnosisGo to Step 3
3 Check the “Fuel Pump” fuse (20A).
If the fuse is burnt out, repair as necessary.
Was the problem found?—Verify repair Go to Step 4
4 Check for poor/faulty connection at the fuel pump, fuel
pump relay or ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found?
—Verify repair Go to Step 5
5 Using the DVM and check the fuel pump relay.
1. Ignition “Off”, engine “Off”.
2. Remove the fuel pump relay from the relay box .
3. Check the relay coil.
Was the DVM indicated specified value?
120 - 150
Go to Step 6Replace fuel
pump relay and
verify repair
11C56(J2)
F2 X2
Fuel Pump Relay

 




ENGINE DRIVEABILITY AND EMISSIONS 6E–117
P0351 A Ignition 1 Control Circuit #1 or #4cylinder ignition signals are not
detected consecutively.No fail-safe function. Consecutive ignition signals are detected. 1. Ignition coil module 1 harness open
circuit, short to ground or short to voltage
circuit.
2. Ignition coil module malfunction.
3. ECM malfunction.J1-19
P0352 A Ignition 2 Control Circuit #2 or #3 cylinder ignition signals are not
detected consecutively.1. Ignition coil module 2 harness open circuit,
short to ground or short to voltage circuit.
2. Ignition coil module malfunction.
3. ECM malfunction.J1-18
P0443 B EVAP Emission Control System Purge
Control CircuitEVAP purge solenoid circuit open, short to
ground or short to voltage circuit.No fail-safe function. EVAP purge solenoid circuit is correct
condition.1. Solenoid harness open circuit, short to
ground or short to voltage circuit.
2. Solenoid malfunction.
3. ECM malfunction.J1-5
P0502 B Vehicle Speed Sensor Circuit Low Input 1. No DTC relating to MAP sensor, TPS,
ECT sensor, injector control circuit and
ignition control circuit.
2. Engine is running.
3. Vehicle speed is below 3km/h in power
condition or 2km/h in deceleration
condition.ECM uses 0km/h condition as
substitute.VSS circuit correct condition. 1. Sensor harness open circuit, short to
ground circuit or short to voltage circuit.
2. Poor connector connection.
3. VSS malfunction.
4. ECM malfunction.J2-23
P0562 D System Voltage Low Battery voltage is below 11V. No fail-safe function. Battery voltage is between 11V and 16V. 1. Battery power feed harness open circuit
or short to ground circuit.
2. ECM ground harness open or poor
connection.
3. Poor connector connection.
4. Battery malfunction.
5. Charge system malfunction.
6. ECM malfunction.-
P0563 A System Voltage High Battery voltage is above 16V.1. Charge system malfunction.
2. Battery jump start cable misconnect.
3. ECM malfunction.-
P0601 A ECM Memory Checksum ECM memory area error. Engine control disabled. Memory are is OK. ECM malfunction. -
P0602 - ECU Programming Error ECM memory area error. Engine control disabled. Memory are is OK. ECM is not programmed. -
P0650 A Malfunction Indicator Lamp (MIL) Control
Circuit MalfunctionCheck engine lamp circuit open, short to
ground or short to voltage circuit.No fail-safe function. Check engine lamp circuit is correct
condition.1. Solenoid harness open circuit, short to
ground or short to voltage circuit.
2. Solenoid malfunction.
3. ECM malfunction.J2-32 Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM
Pin No.

6E–154 ENGINE DRIVEABILITY AND EMISSIONS
9 1. Using the Tech 2, ignition “On” and engine “On”.
2. Monitor the “Manifold Absolute Pressure” in the
data display.
Does the Tech 2 indicate correct “Manifold Absolute
Pressure” in accordance with engine speed or
acceleration? —Go to Step 11Go to Step 10
10 Remove the MAP sensor and check for the following
conditions.
Objects blocking the air cleaner.
Objects blocking the MAP sensor.
Objects blocking the throttle valve.
Vacuum leaking at intake duct.
Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?—Verify repair Go to Step 11
11 1. Using the Tech 2, ignition “On” and engine “On”.
2. Select the “Miscellaneous Test” and perform the
“IAC Control” in the “IAC System”.
3. Operate the Tech 2 in accordance with procedure.
Was the engine speed changed, when the IAC valve
is operating step by step?—Go to Step 13Go to Step 12
12 Check for the following conditions.
Objects blocking the IAC valve.
Objects blocking the throttle valve.
Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?—Verify repair Go to Step 13
13 Check for injector for the affected bank.
Refer to “Injector Coil Test & Injector Balance Test
Procedure” 6E-98 page.
Was the injector operation correct?
—Go to Step 14Refer to Injector
Coil Test &
Injector
Balance Test
Procedure
14 Check for fuel pressure.
Refer to “Fuel System Diagnosis” 6E-108 page.
Was the fuel pressure correct? —Go to Step 15Refer to Fuel
System
Diagnosis
15 Replace the O
2 sensor.
Was the problem solved?—Verify repair Go to Step 16
16 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 17
17 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Veri fy repai r— Step A ction Value(s) Yes No