4C±2
DRIVE SHAFT SYSTEM
Service Precaution
WARNING: I F S O E Q U IPPED 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.
General Description
This publication contains essential removal, installation,
adjustment and maintenance procedures.
The front axle utilizes a central disconnect type front
axle/transfer case system.
The drive axles are completely flexible assemblies,
consisting of inner and outer constant velocity (CV) drive
shaft joints connected by an axle shaft.
For description of propeller shaft and universal joint, refer
to Front/Rear Propeller Shaft in this section.
6E±88
ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Diagnosis
140RW020
Legend
(1) Fuel Filler Cap
(2) Fuel Tank
(3) Rollover Valve
(4) Fuel Pump and Sender Assembly
(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
(15) Evapo Shut Off Valve
Circuit Description
When the ignition switch is turned ªON,º the powertrain
control module (PCM) will turn ªONº the in-tank fuel
pump. The in-tank fuel pump will remain ªONº as long as
the engine is cranking or running and the PCM is receiving
58X crankshaft position pulses. If there are no 58X
crankshaft position pulses, the PCM will turn the in-tank
fuel pump ªOFFº 2 seconds after the ignition switch is
turned ªONº or 2 seconds after the engine stops running.
The in-tank fuel pump is an electric pump within an
integral reservoir. The in-tank fuel pump supplies fuel
through an in-line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure above
the pressure needed by the fuel injectors. A fuel pressure
regulator, attached to the fuel rail, keeps the fuel available
to the fuel injectors at a regulated pressure. Unused fuel
is returned to the fuel tank by a separate fuel return line.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Connect the fuel pressure gauge to the fuel feed line
as shown in the fuel system illustration. Wrap a
shop towel around the fuel pressure connection in
order to absorb any fuel leakage that may occur
when installing the fuel pressure gauge. With the
ignition switch ªONº and the fuel pump running, the
fuel pressure indicated by the fuel pressure gauge
should be 333-376 kPa (48-55 psi). This pressure
is controlled by the amount of pressure the spring
inside the fuel pressure regulator can provide.
3. A fuel system that cannot maintain a constant fuel
pressure has a leak in one or more of the following
areas:
The fuel pump check valve.
The fuel pump flex line.
6E±339 ENGINE DRIVEABILITY AND EMISSIONS
0005
PCM Components
The PCM is designed to maintain exhaust emission levels
to government mandated standards while providing
excellent driveability and fuel efficiency. The PCM
monitors numerous engine and vehicle functions via
electronic sensors such as the throttle position (TP)
sensor, heated oxygen sensor (HO2S), and vehicle
speed sensor (VSS). The PCM also controls certain
engine operations through the following:
Fuel injector control
Ignition control module
Knock sensor
Automatic transmission shift functions
Cruise control
A/C clutch control
PCM Voltage Description
The PCM supplies a buffered voltage to various switches
and sensors. It can do this because resistance in the
PCM is so high in value that a test light may not illuminate
when connected to the circuit. An ordinary shop
voltmeter may not give an accurate reading because the
voltmeter input impedance is too low. Use a 10-megohm
input impedance digital voltmeter (such as J 39200) to
assure accurate voltage readings.
The input/output devices in the PCM include
analog-to-digital converters, signal buffers, counters,
and special drivers. The PCM controls most components
with electronic switches which complete a ground circuit
when turned ªON.º These switches are arranged in
groups of 4 and 7, called either a surface-mounted quad
driver module (QDM), which can independently control up
to 4 output terminals, or QDMs which can independently
control up to 7 outputs. Not all outputs are always used.
PCM Input/Outputs
Inputs ± Operating Conditions Read
Air Conditioning ªONº or ªOFFº Engine Coolant Temperature
Crankshaft Position
Exhaust Oxygen Content
Electronic Ignition
Manifold Absolute Pressure
Battery Voltage
Throttle Position
Vehicle Speed
Fuel Pump Voltage
Power Steering Pressure
Intake Air Temperature
Mass Air Flow
Engine Knock
Camshaft Position
Outputs ± Systems Controlled
Exhaust Gas Recirculation (EGR)
Ignition Control
Fuel Control
Idle Air Control
Electric Fuel Pump
Air Conditioning
Diagnostics
± Malfunction Indicator Lamp (Service Engine Soon
lamp)
± Data Link Connector (DLC)
± Data Output
Transmission Control Module
Alternator Gain Control
PCM Service Precautions
The PCM is designed to withstand normal current draws
associated with vehicle operation. Avoid overloading any
circuit. When testing for opens and shorts, do not ground
or apply voltage to any of the PCM's circuits unless
instructed to do so. These circuits should only be tested
Tech-2. The PCM should remain connected to the PCM
or to a recommended breakout box.
Reprogramming The PCM
The Trooper allow reprogramming of the PCM without
removing it from the vehicle . This provides a flexible and
cost-effective method of making changes in software
calibrations.
The service programming system (SPS) will not allow
incorrect software programming or incorrect calibration
changes.
Refer to the UBS 98model year Immobilizer Workshop
Manual.
Throttle Position (TP) Sensor
The throttle position (TP) sensor is a potentiometer
connected to the throttle shaft on the throttle body. The
PCM monitors the voltage on the signal line and
calculates throttle position. As the throttle valve angle is
changed (accelerator pedal moved), the TP sensor signal
also changes. At a closed throttle position, the output of
7A±19 AUTOMATIC TRANSMISSION (4L30±E)
Chart 13: Shudder Only During Torque Converter Clutch (TCC) Applying
StepActionYe sNo
11. TCC shudder is one of the most commonly misdiagnosed
conditions in an automatic transmission. The key to
diagnosing TCC shudder is to note when it happens and under
what conditions. Once the TCC has been fully applied, it is
nearly impossible to make it shudder. TCC shudder (short
burst of noise normally less than 1 second) will only occur
during clutch applying. It is not a steady state condition.
2. Drive until whole drivetrain is at normal operating temperature.
± On 4WD vehicles, the test must be performed with transfer
case selector lever in ª2Hº position.
± Shudder is a short burst of noise normally less than 1 second
in duration, and can be induced by the following maneuver:
3. From coast condition at 50 mph in ªDº range (Normal mode),
depress the throttle to 1/4-1/3 throttle. If present, shudder will
occur within 5 seconds together with TCC application.(The
scan tool may be used to determine the exact time of TCC
applying)
Was the problem found?
Replace
transmission fluid
and filter (remove
both pans) and
flush cooler lines.
Replace
converter
assembly and
O-ring on turbine
shaft
Perform
mechanical
inspection of
other drivetrain
components.
Chart 14: Possible Causes Of Transmission Noise
CAUTION: Before checking transmission for what
is believed to be transmission noise, ensure
presence and positioning of insulating plugs, pads
etc. Also make sure that noise does not come from
other drivetrain components.
Condition
Possible causeCorrection
Whine or BuzzOil level lowFill with ATF, check for external
leaks.
Plugged or restricted oil filterInspect oil filter.
Replace oil filter or ATF as necessary.
Damaged oil filter gasketReplace oil filter gasket.
Knocking noise from front of
transmission
Loose bolts (Converter to flex plate)Tighten to specifications.
transmission.Cracked or broken flex plateReplace flex plate.
Converter damagedReplace converter.
Knocking noise while driving, mostly
on acceleration.Transmission mount loose or brokenTighten mount bolts or replace
transmission mount.
Cooler line mounts loose or brokenTighten or replace cooler line
mounts.
Cooler lines touching body or frameRepair or replace as necessary.
Knocking noise when vehicle is
stationary
Loose flex plate mounting boltsTighten to specifications.
stationary.Cracked or broken flex plateReplace flex plate.
Damaged converterReplace converter.