2002 ISUZU AXIOM tow

5A±10BRAKE CONTROL SYSTEM
System Components
Electronic Hydraulic Control Unit (EHCU), three Wheel
Speed Sensors, Warning Light, and G-sensor.
Electronic Hydraulic Control Unit (EHCU)
The EHCU consists of ABS control circuits, fault detector,
and a fail-safe. The signal received from each sensor
activates the hydraulic unit accordingly and cancels the
ABS to return to normal braking if a malfunction occurs in
the ABS system.
The EHCU has a self-diagnosing function which can
indicate faulty circuits during diagnosis.
The EHCU is mounted on the engine compartment rear
right side. It consists of a Motor, Plunger Pump, Solenoid
Valves.
Solenoid Valves: Reduces or holds the caliper fluid
pressure for each front disc brake or both rear disc brakes
according to the signal sent from the EHCU.
Reservoir: Temporarily holds the brake fluid that returns
from the front and rear disc brake caliper so that pressure
of front disc brake caliper can be reduced smoothly.
Plunger Pump: Feeds the brake fluid held in the reservoir
to the master cylinder.
Motor: Drives the pump according to the signal from
EHCU.
Check Valve: Controls the brake fluid flow.
ABS Warning Light
821R200015Vehicles equipped with the Anti-lock Brake System have
an amber ªABSº warning light in the instrument panel.
The ªABSº warning light will illuminate if a malfunction in
the Anti-lock Brake System is detected by the Electronic
Hydraulic Control Unit (EHCU).In case of an electronic
malfunction, the EHCU will turn ªONº the ªABSº warning
light and disable the Anti-lock braking function.
The ªABSº light will turn ªONº for approximately three
seconds after the ignition switch is turned to the ªONº
position.If the ªABSº light stays ªONº after the ignition switch is
turned to the ªONº position, or comes ªONº and stays
ªONº while driving, the Anti-lock Brake System should be
inspected for a malfunction according to the diagnosis
procedure.
Wheel Speed Sensor
It consists of a sensor and a rotor. The sensor is attached
to the knuckle on the front wheels and to the rear axle
case on the rear differential.
The front sensor rotor is attached to the each brake rotor
by bolts.
The rear rotor is press-fit in the differential case.
The magnetic flux generated from electrodes magnetized
by a magnet in the sensor varies due to rotation of the
rotor, and the electromagnetic induction generates
alternating voltage in the coil. This voltage draws a ªsine
curveº with the frequency proportional to rotor speed and
it allows detection of wheel speed.
G-Sensor
The G-sensor installed inside the EHCU detects the
vehicle deceleration speed and sends a signal to the
EHCU. In 4WD operation, all four wheels may be
decelerated in almost the same phase, since all wheels
are connected mechanically.
This tendency is noticeable particularly on roads with low
friction coefficient, and the ABS control is adversely
affected.
The G-sensor judges whether the friction coefficient of
road surface is low or high, and changes the EHCU's
operating system to ensure ABS control.
Normal and Anti-lock Braking
Under normal driving conditions, the Anti-lock Brake
System functions the same as a standard power assisted
brake system. However, with the detection of wheel
lock-up, a slight bump or kick-back will be felt in the brake
pedal. This pedal ªbumpº will be followed by a series of
short pedal pulsations which occurs in rapid succession.
The brake pedal pulsation will continue until there is no
longer a need for the anti-lock function or until the vehicle
is stopped. A slight ticking or popping noise may be heard
during brake applications when the Anti-lock features is
being used.
When the Anti-lock feature is being used, the brake pedal
may rise even as the brakes are being applied. This is
also normal. Maintaining a constant force on the pedal
will provide the shortest stopping distance.
Brake Pedal Travel
Vehicles equipped with the Anti-lock Brake System may
be stopped by applying normal force to the brake pedal.
Although there is no need to push the pedal beyond the
point where it stops or holds the vehicle, by applying more
force the pedal will continue to travel toward the floor.
This extra brake pedal travel is normal.

5C±4
POWER±ASSISTED BRAKE SYSTEM
Disc Brake
Front Disc Brake
A05RW001
Rear Disc Brake (4y4 Model)
A05RW002
The disc brake assembly consists of a caliper, piston,
rotor, pad assembly and support bracket. The caliper
assembly has a single bore and is mounted to the support
bracket with two mounting bolts. The support bracket
allows the caliper to move laterally against the rotor. The
caliper is a one±piece casting with the inboard side
containing the piston bore. A square cut rubber seal is
located in a groove in the piston bore which provides the
hydraulic seal between the piston and the cylinder wall.
NOTE:
1. Replace all components included in repair kits used to
service this caliper.
2. Lubricate rubber parts with clean brake fluid to ease
assembly.3. If any hydraulic component is removed or
disconnected, it may be necessary to bleed all or part
of the brake system.
4. Replace pads in axle sets only.
5. The torque values specified are for dry, unlubricated
fasteners.
6. Perform the service operation on a clean bench free
from all mineral oil materials.
Operation
Hydraulic pressure, created by applying the brake pedal,
is converted by the caliper to a stopping force. This force
creates a clamping action of the piston pressing towards
the rotors (outward) and the caliper slides inward toward
the vehicle. This clamping action forces the linings
against the rotor, creating friction to stop the vehicle.

5C±6
POWER±ASSISTED BRAKE SYSTEM
Diagnosis
Road Testing The Brakes
Brake Test
Brakes should be tested on a dry, clean, reasonably
smooth and level roadway. A true test of brake
performance cannot be made if the roadway is wet,
greasy or covered with loose dirt where all tires do not grip
the road equally. Testing will also be adversely affected if
the roadway is crowned so as to throw the weight of the
vehicle toward wheels on one side or if the roadway is so
rough that wheels tend to bounce. Test the brakes at
different vehicle speeds with both light and heavy pedal
pressure; however, avoid locking the wheels and sliding
the tires. Braking without locking the tires will stop the
vehicle in less distance than braking to a skid (which has
no brake efficiency). More tire to road friction is present
while braking without locking the tires than braking to a
skid.
The standard brake system is designed and balanced to
avoid locking the wheels except at very high deceleration
levels.
It is designed this way because the shortest stopping
distance and best control is achieved without brake
lock±up.
Because of high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
External Conditions That Affect Brake Performance
1. Tires: Tires having unequal contact and grip on the
road will cause unequal braking. Tires must be
equally inflated, identical in size, and the thread
pattern of right and left tires must be approximately
equal.
2. Vehicle Loading: A heavily loaded vehicle requires
more braking effort.
3. Wheel Alignment: Misalignment of the wheels,
particularly in regard to excessive camber and caster,
will cause the brakes to pull to one side.
Brake Fluid Leaks
With engine running at idle and the transmission in
ªNeutralº, depress the brake pedal and hold a constant
foot pressure on the pedal. If pedal gradually falls away
with the constant pressure, the hydraulic system may be
leaking.
Check the master cylinder fluid level. While a slight drop in
the reservoir level will result from normal lining wear, an
abnormally low level in reservoir indicates a leak in the
system. The hydraulic system may be leaking internally
as well as externally. Refer to
Master Cylinder Inspection.
Also, the system may appear to pass this test but still
have slight leakage. If fluid level is normal, check the
vacuum booster push rod length. If an incorrect length
push rod is found, adjust or replace the push rod. Check
the brake pedal travel and the parking brake adjustment.
When checking the fluid level, the master cylinder fluid
level may be lower than the ªMAXº mark if the front and
rear linings are worn. This is normal.
Warning Light Operation
When the ignition switch is in the START position, the
ªBRAKEº warning light should turn on and go off when the
ignition switch returns to the ON position.
The following conditions will activate the ªBRAKEº light:
1. Parking brake applied. The light should be on
whenever the parking brake is applied and the ignition
switch is on.
2. Low fluid level. A low fluid level in the master cylinder
will turn the ªBRAKEº light on.
3. During engine cranking the ªBRAKEº light should
remain on. This notifies the driver that the warning
circuit is operating properly.

5C±64
POWER±ASSISTED BRAKE SYSTEM
Disc Brake
Front Disc Brake
A05R200001
Rear Disc Brake (4y4 Model)
A05RW002
The disc brake assembly consists of a caliper, piston,
rotor, pad assembly and support bracket. The caliper
assembly has a fornt dual bore, rear single bore and is
mounted to the support bracket with two mounting bolts.
The support bracket allows the caliper to move laterally
against the rotor. The caliper is a one±piece casting with
the inboard side containing the piston bore. A square cut
rubber seal is located in a groove in the piston bore which
provides the hydraulic seal between the piston and the
cylinder wall.
NOTE:
1. Replace all components included in repair kits used to
service this caliper.
2. Lubricate rubber parts with clean brake fluid to ease
assembly.3. If any hydraulic component is removed or
disconnected, it may be necessary to bleed all or part
of the brake system.
4. Replace pads in axle sets only.
5. The torque values specified are for dry, unlubricated
fasteners.
6. Perform the service operation on a clean bench free
from all mineral oil materials.
Operation
Hydraulic pressure, created by applying the brake pedal,
is converted by the caliper to a stopping force. This force
creates a clamping action of the piston pressing towards
the rotors (outward) and the caliper slides inward toward
the vehicle. This clamping action forces the linings
against the rotor, creating friction to stop the vehicle.

5C±66
POWER±ASSISTED BRAKE SYSTEM
Diagnosis
Road Testing The Brakes
Brake Test
Brakes should be tested on a dry, clean, reasonably
smooth and level roadway. A true test of brake
performance cannot be made if the roadway is wet,
greasy or covered with loose dirt where all tires do not grip
the road equally. Testing will also be adversely affected if
the roadway is crowned so as to throw the weight of the
vehicle toward wheels on one side or if the roadway is so
rough that wheels tend to bounce. Test the brakes at
different vehicle speeds with both light and heavy pedal
pressure; however, avoid locking the wheels and sliding
the tires. Braking without locking the tires will stop the
vehicle in less distance than braking to a skid (which has
no brake efficiency). More tire to road friction is present
while braking without locking the tires than braking to a
skid.
The standard brake system is designed and balanced to
avoid locking the wheels except at very high deceleration
levels.
It is designed this way because the shortest stopping
distance and best control is achieved without brake
lock±up.
Because of high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
External Conditions That Affect Brake Performance
1. Tires: Tires having unequal contact and grip on the
road will cause unequal braking. Tires must be
equally inflated, identical in size, and the thread
pattern of right and left tires must be approximately
equal.
2. Vehicle Loading: A heavily loaded vehicle requires
more braking effort.
3. Wheel Alignment: Misalignment of the wheels,
particularly in regard to excessive camber and caster,
will cause the brakes to pull to one side.
Brake Fluid Leaks
With engine running at idle and the transmission in
ªNeutralº, depress the brake pedal and hold a constant
foot pressure on the pedal. If pedal gradually falls away
with the constant pressure, the hydraulic system may be
leaking.
Check the master cylinder fluid level. While a slight drop in
the reservoir level will result from normal lining wear, an
abnormally low level in reservoir indicates a leak in the
system. The hydraulic system may be leaking internally
as well as externally. Refer to
Master Cylinder Inspection.
Also, the system may appear to pass this test but still
have slight leakage. If fluid level is normal, check the
vacuum booster push rod length. If an incorrect length
push rod is found, adjust or replace the push rod. Check
the brake pedal travel and the parking brake adjustment.
When checking the fluid level, the master cylinder fluid
level may be lower than the ªMAXº mark if the front and
rear linings are worn. This is normal.
Warning Light Operation
When the ignition switch is in the START position, the
ªBRAKEº warning light should turn on and go off when the
ignition switch returns to the ON position.
The following conditions will activate the ªBRAKEº light:
1. Parking brake applied. The light should be on
whenever the parking brake is applied and the ignition
switch is on.
2. Low fluid level. A low fluid level in the master cylinder
will turn the ªBRAKEº light on.
3. During engine cranking the ªBRAKEº light should
remain on. This notifies the driver that the warning
circuit is operating properly.

6A±3
ENGINE MECHANICAL (6VE1 3.5L)
General Description
Engine Cleanliness And Care
An automobile engine is a combination of many
machined, honed, polished and lapped surfaces with
tolerances that are measured in the thousandths of a
millimeter (ten thousandths of an inch). Accordingly,
when any internal engine parts are serviced, care and
cleanliness are important. Throughout this section, it
should be understood that proper cleaning and protection
of machined surfaces and friction areas is part of the
repair procedure. This is considered standard shop
practice even if not specifically stated.

A liberal coating of engine oil should be applied to all
friction areas during assembly to protect and lubricate
the surfaces on initial operation.

Whenever valve train components, pistons, piston
rings, connecting rods, rod bearings, and crankshaft
journal bearings are removed for service, they should
be retained in order.

At the time of installation, they should be installed in
the same locations and with the same mating
surfaces as when removed.

Battery cables should be disconnected before any
major work is performed on the engine. Failure to
disconnect cables may result in damage to wire
harness or other electrical parts.

The six cylinders of this engine are identified by
numbers; Right side cylinders 1, 3 and 5, Left side
cylinders 2, 4 and 6, as counted from crankshaft
pulley side to flywheel side.
General Information on Engine Service
The following information on engine service should be
noted carefully, as it is important in preventing damage
and contributing to reliable engine performance.

When raising or supporting the engine for any reason,
do not use a jack under the oil pan. Due to the small
clearance between the oil pan and the oil pump
strainer, jacking against the oil pan may cause
damage to the oil pick±up unit.

The 12±volt electrical system is capable of damaging
circuits. When performing any work where electrical
terminals could possibly be grounded, the ground
cable of the battery should be disconnected at the
battery.

Any time the intake air duct or air cleaner is removed,
the intake opening should be covered. This will
protect against accidental entrance of foreign
material into the cylinder which could cause extensive
damage when the engine is started.
Cylinder Block
The cylinder block is made of aluminum die±cast casting
for 75
V±type six cylinders. It has a rear plate integrated
structure and employs a deep skirt. The cylinder liner is
cast and the liner inner diameter and crankshaft journal
diameter are classified into grades. The crankshaft is
supported by four bearings of which width is different
between No.2, No.3 and No.1, No.4; the width of No.3
bearing on the body side is different in order to support the
thrust bearing. The bearing cap is made of nodular cast
iron and each bearing cap uses four bolts and two side
bolts.
Cylinder Head
The cylinder head, made of aluminum alloy casting
employs a pent±roof type combustion chamber with a
spark plug in the center. The intake and exhaust valves
are placed in V±type design. The ports are cross±flow
type.
Valve Train
Intake and exhaust camshaft on both banks are driven
with a camshaft drive gear by the timing belt. The valves
are operated by the camshaft and the valve clearance is
adjusted to select suitable thickness shim.
Intake Manifold
The intake manifold system is composed of the aluminum
cast common chamber and intake manifold attached with
six fuel injectors.
Exhaust Manifold
The exhaust manifold is made of nodular cast iron.
Pistons and Connecting Rods
Aluminum pistons are used after selecting the grade that
meets the cylinder bore diameter. Each piston has two
compression rings and one oil ring. The piston pin made
of chromium steel is offset 1mm toward the thrust side,
and the thrust pressure of piston to the cylinder wall varies
gradually as the piston travels. The connecting rods are
made of forged steel. The connecting rod bearings are
graded for correct size selection.
Crankshaft and Bearings
The crankshaft is made of Ductile cast±iron. Pins and
journals are graded for correct size selection for their
bearing.

6A±16
ENGINE MECHANICAL (6VE1 3.5L)
Engine Oil Consumption Excessive
ConditionPossible causeCorrection
Oil leakingOil pan drain plug looseRetighten or replace gasket
Crankcase fixing bolts loosenedRetighten
Oil pan setting bolts loosenedRetighten
Oil pan gasket brokenReplace gasket
Front cover retaining bolts loose or
gasket brokenRetighten or replace gasket
Head cover fixing bolts loose or
gasket brokenRetighten or replace gasket
Oil filter adapter crackedReplace
Oil filter attachings bolt loose or
rubber gasket brokenRetighten or replace oil filter
Crankshaft front or rear oil seal
defectiveReplace oil seal
Oil pressure unit loose or brokenRetighten or replace
Blow±by gas hose brokenReplace hose
Positive Crankcase Ventilation Valve
cloggedClean
Engine/Transmission coupling failedReplace oil seal
Oil leaking into combustion
chambers due topoor seal in valve
Valve stem oil seal defectiveReplace
chambers due to oor seal in valve
systemValve stem or valve guide wornReplace valve and valve guide
Oil leaking into combustion
chambers due to poor seal in cylinder
t
Cylinders and pistons worn
excessivelyReplace cylinder body assembly and
pistons
partsPiston ring gaps incorrectly
positionedCorrect
Piston rings set with wrong side upCorrect
Piston ring stickingReplace cylinder body assembly and
pistons
Piston ring and ring groove wornReplace pistons and others
Return ports in oil rings cloggedClean piston and replace rings
Positive Crankcase Ventilation
System malfunctioningPositive Crankcase Ventilation Valve
cloggedClean
OthersImproper oil viscosityUse oil of recommended S.A.E.
viscosity
Continuous high speed driving
and/or severe usage such as trailer
towingContinuous high speed operation
and/or severe usage will normally
cause increased oil consumption

ENGINE ELECTRICAL (6VE1 3.5L)6D1±3
Battery Charging
Observe the following safety precautions when charging
the battery:
1. Never attempt to charge the battery when the fluid
level is below the lower level line on the side of the
battery. In this case, the battery must be replaced.
2. Pay close attention to the battery during charging
procedure.
Battery charging should be discontinued or the rate of
charge reduced if the battery feels hot to the touch.
Battery charging should be discontinued or the rate of
charge reduced if the battery begins to gas or spew
electrolyte from the vent holes.
3. In order to more easily view the hydrometer blue dot
or ring, it may be necessary to jiggle or tilt the battery.
4. Battery temperature can have a great effect on
battery charging capacity.
5. The sealed battery used on this vehicle may be either
quick charged or slow charged in the same manner as
other batteries.
Whichever method you decide to use, be sure that
you completely charge the battery. Never partially
charge the battery.
Jump Starting
Jump Starting with an Auxiliary (Booster)
Battery
CAUTION: Never push or tow the vehicle in an
attempt to start it. Serious damage to the emission
system as well as other vehicle parts will result.
Treat both the discharged battery and the booster
battery with great care when using jumper cables.
Carefully follow the jump starting procedure, being
careful at all times to avoid sparking.
WARNING: FAILURE TO CAREFULLY FOLLOW THE
JUMP STARTING PROCEDURE COULD RESULT IN
THE FOLLOWING:
1. Serous personal injury, particularly to your eyes.
2. Property damage from a battery explosion, battery
acid, or an electrical fire.
3. Damage to the electronic components of one or both
vehicles particularly.
Never expose the battery to an open flame or electrical
spark. Gas generated by the battery may catch fire or
explode.
Remove any rings, watches, or other jewelry before
working around the battery. Protect your eyes by wearing
an approved set of goggles.
Never allow battery fluid to come in contact with your eyes
or skin.Never allow battery fluid to come in contact with fabrics or
painted surfaces.
Battery fluid is a highly corrosive acid.
Should battery fluid come in contact with your eyes, skin,
fabric, or a painted surface, immediately and thoroughly
rinse the affected area with clean tap water.
Never allow metal tools or jumper cables to come in
contact with the positive battery terminal, or any other
metal surface of the vehicle. This will protect against a
short circuit.
Always keep batteries out of reach of young children.
Jump Starting Procedure
1. Set the vehicle parking brake.
If the vehicle is equipped with an automatic
transmission, place the selector level in the ªPARKº
position.
If the vehicle is equipped with a manual transmission,
place the shift lever in the ªNEUTRALº position.
Turn ªOFFº the ignition.
Turn ªOFFº all lights and any other accessory
requiring electrical power.
2. Look at the built±in hydrometer.
If the indication area of the built±in hydrometer is
completely clear, do not try to jump start.
3. Attach the end of one jumper cable to the positive
terminal of the booster battery.
Attach the other end of the same cable to the positive
terminal of the discharged battery.
Do not allow the vehicles to touch each other. This will
cause a ground connection, effectively neutralizing
the charging procedure.
Be sure that the booster battery has a 12 volt rating.
4. Attach one end of the remaining cable to the negative
terminal of the booster battery.
Attach the other end of the same cable to a solid
engine ground (such as the air conditioning
compressor bracket or the generator mounting
bracket) of the vehicle with the discharged battery.
The ground connection must be at least 450 mm (18
in.) from the battery of the vehicle whose battery is
being charged.
WARNING: NEVER ATTACH THE END OF THE
JUMPER CABLE DIRECTLY TO THE NEGATIVE
TERMINAL OF THE DEAD BATTERY.
5. Start the engine of the vehicle with the good battery.
Make sure that all unnecessary electrical accessories
have been turned ªOFFº.
6. Start the engine of the vehicle with the dead battery.