2002 ISUZU AXIOM run flat

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.

5C±67 POWER±ASSISTED BRAKE SYSTEM
General Diagnosis
ConditionPossible causeCorrection
Brake PullTire inflation pressure is unequal.Adjust
Front wheel alignment is incorrect.Adjust
Unmatched tires on same axle.Tires with approx. the same amount
of tread should be used on the same
axle.
Restricted brake pipes or hoses.Check for soft hoses and damaged
lines. Replace with new hoses and
new double walled steel brake
piping.
Water or oil on the brake pads.Clean or replace.
Brake pads hardened.Replace
Brake pads worn excessively.Replace
Brake rotor worn or scored.Grind or replace.
Disc brake caliper malfunctioning.Clean or replace.
Front hub bearing preload incorrect.Adjust or replace.
Loose suspension parts.Check all suspension mountings.
Loose calipers.Check and tighten the bolts to
specifications.
Brake Roughness or Chatter
(Pulsates)Excessive lateral runout.Check per instructions. If not within
specifications, replace or machine
the rotor.
Parallelism not within specifications.Check per instructions. If not within
specifications, replace or machine
the rotor.
Pad reversed (steel against iron).Replace the brake pad and machine
rotor to within specifications.
Excessive Pedal EffortMalfunctioning vacuum booster.Check the vacuum booster operation
and repair, if necessary.
Partial system failure.Check the front and rear brake
system for failure and repair. Also,
check the brake warning light. If a
failed system is found, the light
should indicate failure.
Excessively worn pad.Check and replace pads in sets.
Piston in caliper stuck or sluggish.Remove caliper and rebuild.
Fading brakes due to incorrect pad.Remove and replace with original
equipment pad or equivalent.
Vacuum leak to vacuum booster.Check for ruptured or loose hose.
Check the direction of check valve
within vacuum hose.Correct vacuum hose direction.
Grease on the brake pads.Replace or clean.
Excessive Brake Pedal TravelAir in hydraulic circuit.Bleed the hydraulic circuit.
Level of brake fluid in the reservoir
too low.Replenish brake fluid reservoir to
specified level and bleed hydraulic
circuit as necessary.
Master cylinder push rod clearance
excessive.Adjust
Leakage in hydraulic system.Correct or replace defective parts.

7A1±2
TRANSMISSION CONTROL SYSTEM (4L30±E)
Service Precaution
WARNING: THIS VEHICLE HAS 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
The 4L30±E is a 4±speed fully automatic transmission. It
uses a microcomputer as a control unit to judge running
conditions including throttle opening rate and vehicle
speed, then it sets the shifting point in the optimum timing
so that best driving performance can be achieved.
In addition, the built±in shift mode select function can
select three shift modes according to the driver's
preference:

Normal mode ±Normal shift pattern.

Winter mode ±Starts in 3rd gear to reduce slippage on
ice or snow.

Power mode has a delayed upshift when more
powerful acceleration is required.
Also, the built±in fail safe function (ªbackup modeº)
assures driving performance even if the vehicle speed
sensor, throttle signal or any solenoid fails.
Further, the self±diagnostic function conducts diagnosis
in a short time when the control system fails, thus
improving serviceability.
The major features of 4L30±E are as follows:

A compact structure consisting of 2 sets of planetary
gears and flat torque converter.

Electronic control selects the optimum shift mode
according to the driving conditions.

Electronic control maintains the optimum hydraulic
pressure for clutch, band brake as well as
transmission so that shift feeling is improved.

Two sets of planetary gears reduce friction of power
train.
Also, a lockup mechanism in the torque converter
reduces fuel consumption.

Wide gear ratio and high torque rate of torque
converter provide excellent starting performance.

SUPPLEMENTAL RESTRAINT SYSTEM 9J±6
There is a shorting clip on the passenger air bag
assembly connector which connects to the SRS harness.
The shorting clip shorts across the passenger air bag
assembly circuit when the passenger air bag assembly
connector is disconnected. The circuit to the passenger
air bag assembly is shorted in this way to help prevent
unwanted deployment of the air bag when servicing the
passenger air bag assembly, the instrument panel or
other SRS components.
827RY00001
Legend
(1) Passenger Air Bag Door
(2) Passenger Air Bag Assembly
(3) Passenger Air Bag Harness
(4) Cross Beam
Steering Column
The steering column absorbs energy and is designed to
compress in a frontal crash to decrease the chance of
injury to the driver.
431R200006
Knee Bolster
The knee bolsters are used to absorb energy to protec
knees and control the forward movement of the vehicle's
front seat occupants during a frontal crash, by limiting leg
movement.
740RS021
Definition
Air Bag
An inflatable cloth cushion designed to deploy in certain
frontal crashes. It supplements the protection offered by
the seat belts by distributing the impact load more evenly
over the vehicle occupant's head and torso.
Asynchronous
Performed in a nonperiodic fashion, (i. e., no defined time
or interval).
(B+)
Battery voltage, (B+) The voltage available at the battery
at the time of the indicated measurement. With the key
ªONº and the engine not running, the system voltage will
likely be between 12 and 12.5 volts. At idle the voltage
may be 14 to 16 volts. The voltage could be as low as 10
volts during engine cranking.
Bulb Check
The SDM will cause the ªAIR BAGº warning lamp to flash
seven times and then go ªOFFº whenever the ignition
switch transitions to the ON position from any other
ignition switch position and no malfunctions are detected.
ªCONTINUOUS MONITORINGº
Tests performed by the SDM on the SRS every 100
milliseconds while ªIgnition 1º voltage is in the normal
operating voltage range at the SDM.
Data Link Connector (DLC)
Formerly ªDLCº a connector which allows communication
with an external computer, such as a scan tool.
Datum Line
A base line parallel to the plane of the underbody or frame
from which all vertical measurements originate.