ESP ISUZU AXIOM 2002 Service Repair Manual

1A±70
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Functions and Features
Automatic air conditioning control unit
The control unit features a prominent control and display
panel that clearly shows air conditioner operational
settings (delivered air volume, air outlet location,
inside/outside air circulation, and set temperature).
Desired temperature can be set in ±17
C (1
F)
increments. The current setting appears on the digital
display.
Automatic temperature control
Vehicle interior temperature is maintained at the set level.
It is unaffected by changes in vehicle speed, outside air
temperature, and number of passengers.
Maximum cooling and heating
Moving the switch to the 18
C (65
F) position provides
maximum cooling. Moving the switch to the 32
C (90
F)
position provides maximum heating.
Automatic air flow control
Air flow is automatically and precisely regulated in
response to set temperature change and/or changes in
heater unit mixing door aperture.
Automatic air outlet selection
Appropriate air outlets (VENT, BE-LEVEL, FOOT, or
DEF) are selected in response to changes in outlet
temperatures. The mode switch permits manual selection
of the desired air outlet.
Air source (Fresh air intake from outside the
vehicle or recirculation of the air inside the vehicle)
selection
Automatic switching between outside air (FRESH),
recirculated inside air (RECIRC), or a combination of the
two (MIX) occurs in response to changes in outlet
temperatures.The intake switch permits manual
selection of the air source (FRESH or RECIRC). Mixing
of the two sources is not possible during manual
operation. When the defrost mode switch (DEF) is
pressed, the system automatically switches to outside air
intake.
Cooler start-up control
When the vehicle is parked in a hot area for an extended
period of time, the evaporator becomes hot. When the
cooler is turned on, hot air is blown into the vehicle until
the evaporator cools down. The cooler start-up control
prevents blower operation until the evaporator is able to
provide cool air.
Heater start-up control
When the vehicle is parked in a cold area for an extended
period of time, the heater core becomes cold. When the
heater is turned on, cold air is blown into the vehicle until
the heater core heats up. The heater start-up control
prevents blower operation to the air outlets until the
heater core is able to provide warm air. Air is delivered
through the defrost outlets.
Solar radiation offset
The sun sensor uses a photodiode to precisely determine
the amount of solar radiation affecting the vehicle. The
cooler operates in response to this radiation to quickly
correct the vehicle interior temperature.Switch position memory
Current switch positions are stored in memory when the
ignition switch is turned off. When the ignition switch is
turned on again, the switches automatically return to the
position they were in when the ignition switch was turned
off. This simplifies the restarting procedure.
Self-diagnosis function
The self-diagnosis switches on the control panel permit
easy system troubleshooting. Refer to ªSelf-Diagnosisº
later in this Section.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±75
A
/
C
´
S
w
i
t
c
hWhen the A/C switch is pressed, the LED light goes out and the
compressor turns off. If the switch is pressed again, the LED light
turns on and the compressor begins to operate.
The air conditioner will not operate if the fan switch is off.
During manual DEF or D/F operation, the A/C LED will turn on or off
in response to switch operation. However, the compressor remains
on regardless of switch position.
D
E
F

M
o
d
e

S
w
i
t
c
hWhen the defrost switch (DEF) is pressed, air flows from the de-
froster outlets. The compressor is on and blower speed is automati-
cally controlled. Air intake is from outside the vehicle (FRESH). The
defroster symbol appears on the display.
When the defrost switch (DEF) is pressed again, the unit returns to
the settings in use before the defroster was turned on.

1A±82
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Automatic Air Conditioning System
System Overview (Chart)
Conditions both inside and outside the vehicle are
detected by sensors (in-car temperature sensor, ambient
temperature sensor, duct sensor, sun sensor, speed
sensor, and water temperature sensor). These sensors
send signals to the control unit.
Potentiometer position sensors send data to the control
unit. Signals related to control panel settings are also sent
to the control unit.In response to the signals received, the control unit
automatically adjusts air-mix door aperture (outlet air
temperature), fan speed (forced air volume), and air
intake (outside air, recirculated inside air, or a mixture of
the two).
F01R200003

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±83
Interior Temperature Control
When the temperature control switch is set to a specific
temperature, a signal is sent to the A/C control unit. Other
signals are sent to the control unit from the various
sensors. This data is analyzed by the control unit which
creates a composite data signal that is compared with the
signal received from the potentiometer. The result
determines the direction of mix actuator rotation.
The mix actuator reacts to the composite air mix door
opening angle signal. Opening angle is increased or
decreased to maintain the temperature at the selected
level.
When the compressor is off, the air mix door moves
toward the COOL side. When the compressor turns on,
the temperature of the air being discharged from the
outlet vents is regulated.
When the temperature control is set to 18
C (65
F), the
air mix door moves to the FULL COOL position. When the
control is set to 32
C (90
F), the door moves to the FULL
HOT position.
In the VENT position, the air mix door moves from FULL
COOL to a 60% aperture. This prevents hot air from being
discharged into the vehicle.
C01R200005
Air Flow Control
In the Auto Mode

Automatic operation
When the AUTO switch or the DEF switch is pressed, a
signal indicating the forced air volume is sent to the A/C
auto-control unit. Other signals are sent to the control
unit from the various sensors. This data is analyzed by
the control unit which creates a composite data signal.
Based on this signal, the base voltage of the power
transistor is varied to change the blower voltage. This
results in a non-stepped change in blower motor
speed.
When the temperature control switch is set to either
18
C (65
F) or 32
C (90
F), blower motor speed is in
the MAX-HI mode.
In the Manual Mode

Manual operation
When the fan switch is manually set to a specified air
volume, a signal is sent to the A/C auto-control-unit. In
response to this signal, the auto-control unit controls
the blower voltage.
When the fan switch is set to HI, the max-hi relay
operates to increase blower motor speed to the
MAX-HI mode.
C01R200001

1A±84
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Mode (Blow Port) Control
The A/C control unit receives temperature setting data as
well as temperature and solar radiation level data from the
various sensors. Based on this data, the control unit
compiles a composite TMO signal. The TMO signal
allows the outlet positions to be changed in a set pattern
(VENT"BI-LEVEL"FOOT"DEFROST/FOOT).
The mode actuator acts in response to mode position. It
compares data signals received from the target mode, the
door position, and mode door position to determine the
direction of rotation.
If the temperature is set to 18
C (65
F), cool air is
discharged from the head outlets. If t he temperature is
set to 32
C (90
F), warm air is discharged from the foot
outlets.
In manual mode, existing air outlet settings remain
unchanged when the temperature is set to 18
C (65
F) or
32
C (90
F).

Press the mode switch to change to the outlet mode.
Blower operation (outlet mode position) can now be
switched between the VENT, BI-LEVEL, FOOT, and DEF
positions.

The DEF position can be selected from the outlet mode.
C01R200003
Intake (Fresh air/interior air switching)
Control
During automatic operation, the A/C control unit responds
to the temperature setting signal together with signals
from the various sensors to generate a general signal that
controls operation in a prescribed pattern.
If either or both the fan and the cooler are off, air intake is
from outside the vehicle.
If the temperature control switch is set to either 18
C
(65
F) or 32
C (90
F), the air inside the vehicle is
recirculated.
1. Manual switch operation
Press the intake switch to change between outside air
intake and recirculated inside air.
2. Defrost switch operation
Air intake is from outside the vehicle.
3. Mode switch operation
During automatic operation, outside air intake or
recirculated inside air is selected as appropriate.
During manual operation or when the DEF mode is
selected, air intake is from outside the vehicle.
C01R200004

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±119
Power Transistor
1. Remove the power transistor connector (C±34) from
the evaporator assembly.
2. Check the conduction between the power transistor
side terminals.
C01R200006
MAX HI Relay
1. Remove the MAX ± HI relay connector (C±35) from
the blower assembly.
2. Check the conduction between the MAX ± HI relay
side terminals.
C01R200011
In Car Sensor
1. Turn on the ignition switch (the engine is started).
Start the air conditioner in ªAutoº.
2. Make sure that the in car sensor suctions cigarette
smokes and such.
In Car Sensor
1. Dismount the in car sensor from the automatic
heater/air conditioner control unit. Connect (+) end
and (±) end of the battery to the aspirator motor side
terminals No.I17±1 and No.I17±2, respectively, then
check if the motor runs normally.
C01R200010

POWER±ASSISTED STEERING SYSTEM2A±5
Power Steering System
There is some noise in all power steering systems. One
of the most common is a hissing sound when the steering
wheel is fully turned and the car is not moving. This noise
will be most evident when the steering wheel is operated
while the brakes are applied. There is no relationshipbetween this noise and steering performance. Do not
replace the valve unless the ªhissingº noise is extremely
objectionable. A replacement valve will also have a slight
noise, and is not always a cure for the condition.
Condition
Possible causeCorrection
Rattle or Chucking NoisePressure hose touching other parts
of vehicle.Adjust hose position. Do not bend
tubing by hand.
Tie rod ends loose.Tighten or replace tie rod end.
Loose steering unit mounting.Tighten steering unit mounting.
Poor Return of Steering Wheel to
Center
Improper front wheel alignment.Adjust front wheel alignment.
CenterWheel bearing worn.Replace front wheel bearing.
Tie rod end binding.Replace tie rod end.
Ball joint binding.Replace ball joint.
Tight or frozen steering shaft
bearing.Replace steering assembly.
Sticky or plugged steering unit valve.Flush or replace steering unit.
Entry of air in the power steering
system.Bleed the system.
Momentary Increase In Effort When
Turning Wheel Fast To Right or Left
High internal leakage.Repair steering gear.
Turning Wheel Fast To Right or LeftPower steering fluid level low.Replenish fluid.
Steering Wheel Surges or Jerks
When Turning Especially During
Insufficient pump pressure.Repair pump assembly.
When Turning Especially During
Parkin
gSticky steering unit valve.Flush or replace steering unit.Parking
Power steering fluid level low.Replenish fluid.
Excessive Wheel Kick Back or Loose
Steering
Air in system.Bleed hydraulic system.
SteeringTie rod end loose.Tighten tie rod end.
Wheel bearing worn.Replace wheel bearing.
Hard Steering or Lack or Power
Assist
Sticky steering unit valve.Flush or replace steering unit.
AssistInsufficient pump pressure.Repair pump assembly.
Excessive internal pump leakage.Repair pump assembly.
Excessive internal steering gear
leakage.Repair steering gear.
Power steering fluid level low.Replenish fluid.
Unstable Engine Idling or Stalling
When TurningPressure switch of the power
steering pump or its harness is faulty.Repair or replace.

3C±8FRONT SUSPENSION
3. Apply the setting marks(2) to the height control arm
and torsion bar, then remove height control arm.
410RS005
4. Apply the setting marks(3) to the torsion bar and
lower control arm, then remove torsion bar.
410RS006
Inspection and Repair
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
Check the following parts:

Torsion bar

Height control arm

Adjust bolt

Rubber seat
Installation
1. Apply grease to the serrated portions, then install
torsion bar. Make sure the bars are on their correct
respective sides and align the setting marks(3).
410RS007
410RS006

WHEEL AND TIRE SYSTEM3E±5
Condition CorrectionPossible cause
Erratic Steering When BrakingWorn wheel bearings.Replace wheel bearings.
Broken or sagging springs.Replace spring (pairs).
Leaking caliper.Repair or replace caliper.
Warped discs.Replace brake disc.
Badly worn brake pads.Replace brake pads.
Tires are inflated unequally.Inflate tires to proper pressure.
Low or Uneven Trim HeightBroken or sagging springs.Replace springs (In pairs).
Vehicle overloaded.Reduce load.
Incorrect springs.Adjust or replace torsion bar.
Suspension BottomsVehicle overloaded. Reduce load.
Faulty shock absorber.Replace shock absorber.
Incorrect, broken or sagging springs.Replace springs.
Body LeansLoose stabilizer bar.Tighten stabilizer bar bolts or replace
bushings.
Faulty shock absorber, struts or
mounting.Replace shock absorber.
Broken or sagging springs.Replace springs (In pairs).
Vehicle overloaded.Reduce load.
Cupped TiresWorn wheel bearings.Replace wheel bearing.
Excessive tire or wheel run out.Replace tire or wheel.
Worn ball joints.Replace ball joints.
Tire out of balance.Adjust tire balance.
Irregular and Premature Wear
480RS001
Irregular and/or premature wear has many causes.
Some of them are incorrect inflation pressures, lack of tire
rotation, poor driving habits or improper wheel alignment.
Incorrect inflation is common cause of tire premature
wear.NOTE: Due to their design, radial tires tend to wear faster
in the shoulder area, particularly on the front tires. This
makes regular rotation especially necessary. After
rotation, be sure to check wheel nut torque, and set tire
pressures.

3E±12WHEEL AND TIRE SYSTEM
Tire
Tire Replacement
When replacement is necessary, the original metric tire
size should be used. Most metric tire sizes do not have
exact corresponding alphanumeric tire sizes. It is
recommended that new tires be installed in pairs on the
same axle. If necessary to replace only one tire, it should
be paired with tire having the most tread, to equalize
braking traction.
CAUTION: Do not mix different types of tires such
as radial, bias and bias-belted tires except in
emergencies, because vehicle handling may be
seriously affected and may result in loss of control.
Tire Dismounting
Remove valve cap on valve step and deflate the tire. Then
use a tire changing machine to mount or dismount tires.
Follow the equipment manufacturer's instruction. Do not
use hand tools or tire lever alone to change tires as they
may damage the tire beads or wheel rim.
Tire Mounting
Rim bead seats should be cleaned with a wire brush or
coarse steel wool to remove lubricants, and light rust.
Before mounting a tire, the bead area should be well
lubricated with an approved tire lubricant.
After mounting, inflate the tire to 196kPa (28 psi) so that
beads are completely seated. Inflate the air to specified
pressure and install valve cap to the stem.
WARNING: NEVER STAND OVER TIRE WHEN
INFLATING. BEAD MAY BREAK WHEN BEAD SNAPS
OVER RIM'S SAFETY HUMP AND CAUSE SERIOUS
PERSONAL INJURY.
NEVER EXCEED 240 KPA (35 PSI) PRESSURE WHEN
INFLATING. IF 240 KPA (35 PSI) PRESSURE WILL
NOT SEAT BEADS, DEFLATE, RE-LUBRICATE AND
RE-INFLATE. OVER INFLATION MAY CAUSE THE
BEAD TO BREAK AND CAUSE SERIOUS PERSONAL
INJURY.
Tire Repair
There are many different materials on the market used to
repair tires.
Manufacturers have published detailed instructions on
how and when to repair tires. These instructions can be
obtained from the tire manufacturer if they are not
included with the repair kit.
Wheel Inspection
Damaged wheels and wheels with excessive run-out
must be replaced.
Wheel run out at rim (Base on hub Bore):
Aluminum
1± Vertical play: Less than 0.55 mm (0.022 in)
2± Horizontal play: Less than 0.55 mm (0.022 in)
480RS012
General Balance Procedure
Deposits of mud, etc. must be cleaned from the inside of
the rim.
The tire should be inspected for the following: match
mount paint marks, bent rims, bulges, irregular tire wear,
proper wheel size and inflation pressure. Then balance
according to the equipment manufacturer's
recommendations.
There are two types of wheel and tire balance.
Static balance is the equal distribution of weight around
the wheel.
Assemblies that are statically unbalanced cause a
bouncing action called tramp. This condition will
eventually cause uneven tire wear.