2002 ISUZU AXIOM check engine

POWER±ASSISTED STEERING SYSTEM2A±25
Inspection and Repair
Make all necessary adjustments, repairs, and part
replacements if wear, damage, or other problems are
discovered during inspection.
Rotor
442RS002Check that the groove in the vane is free from excessive
wear and that the vane slides smoothly. When part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.
Vane
442RS003
Sliding faces of the vane should be free from wear.
(Particularly the curved face at the tip that contact with the
cam should be free from wear and distortion). When part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.
Cam
The inner face of the arm should have a uniform contact
pattern without a sign of step wear. When part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.
Side Plate
The sliding faces of parts must be free from step wear
(more than 0.01 mm), which can be felt by the finger nail.
The parts with minor scores may be reused after lapping
the face.
Relief Valve
The sliding face of the valve must be free from burrs and
damage. The parts with minor scores may be reused after
smoothing with emery cloth (#800 or finer).
Shaft
Oil seal sliding faces must be free from a step wear which
can be felt by the finger nail. Bushing fitting face must be
free from damage and wear.
O-ring, Oil Seal, Snap Ring
Be sure to discard used parts, and always use new parts
for installation. Prior to installation, lubricate all seals and
rings with power steering fluid.
Pressure Switch
Check the switch operation as follows:
With engine idling and A/C on, turn the steering wheel
fully to the left; compressor should interrupt and engine
idle speed will increase. Shut off A/C and again turn
steering fully to the left; engine idle will increase. If system
fails to function properly, disconnect connector at the
pressure switch and repeat system check while testing
continuity across disconnected SW connector.
Reassembly
1. Install oil seal to front housing. Be sure to discard
used oil seal, and always use new parts for
installation.
CAUTION: When installing the oil seal, be careful
not to damage the oil seal contacting surface of the
housing.
2. Install shaft assembly.

INTELLIGENT SUSPENSION3F±1
AXIOM
SUSPENSION
INTELLIGENT SUSPENSION CONTROL
CONTENTS
Service Precaution 3F±2. . . . . . . . . . . . . . . . . . . . . .
General Description 3F±2. . . . . . . . . . . . . . . . . . . . .
PIN ASSIGNMENT TABLE 3F±4. . . . . . . . . . . . .
System Components 3F±4. . . . . . . . . . . . . . . . . . .
Control Unit 3F±4. . . . . . . . . . . . . . . . . . . . . . . . . . .
Actuator 3F±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustable Damping Force Shock Absorber 3F±4
Warning Lamp 3F±4. . . . . . . . . . . . . . . . . . . . . . . .
Vertical G-Sensor 3F±5. . . . . . . . . . . . . . . . . . . . . .
Lateral G-Sensor 3F±5. . . . . . . . . . . . . . . . . . . . . .
Acronyms and Abbreviations 3F±5. . . . . . . . . . . .
General Diagnosis 3F±5. . . . . . . . . . . . . . . . . . . . . . .
General Information 3F±5. . . . . . . . . . . . . . . . . . . .
Service Precautions 3F±5. . . . . . . . . . . . . . . . . . .
Computer System Service Precautions 3F±5. . .
General Service Precautions 3F±5. . . . . . . . . . . .
Parts Handling 3F±5. . . . . . . . . . . . . . . . . . . . . . . .
FLASHING CODES 3F±6. . . . . . . . . . . . . . . . . . . .
CLEAR DTC 3F±7. . . . . . . . . . . . . . . . . . . . . . . . . .
INTERMITTENT CONDITIONS 3F±8. . . . . . . . .
BULB CHECK 3F±8. . . . . . . . . . . . . . . . . . . . . . . . .
DTC CHECK 3F±8. . . . . . . . . . . . . . . . . . . . . . . . . .
Connector List 3F±14. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC)
Identification 3F±16. . . . . . . . . . . . . . . . . . . . . . . . .
DTC2 Actuator Coil Over Current 3F±17. . . . . . . . . .
Circuit Description 3F±17. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 3F±17. . . . . . . . . . . . . . . . . . . . . . . .
DTC3 Actuator Coil/Position Sensor Open
Circuit or Short 3F±19. . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 3F±19. . . . . . . . . . . . . . . . . . . . . Diagnostic Aids 3F±19. . . . . . . . . . . . . . . . . . . . . . . .
DTC4 G-Sensor Open Circuit or Short 3F±22. . . . .
Circuit Description 3F±22. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 3F±22. . . . . . . . . . . . . . . . . . . . . . . .
DTC5 Vehicle Speed Sensor Open Circuit
or Short 3F±23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 3F±23. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 3F±23. . . . . . . . . . . . . . . . . . . . . . . .
DTC6 Stop Lamp Switch Open Circuit
or Short 3F±25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 3F±25. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 3F±25. . . . . . . . . . . . . . . . . . . . . . . .
DTC7 Engine Speed Signal Open Circuit
or Short 3F±27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 3F±27. . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 3F±27. . . . . . . . . . . . . . . . . . . . . . . .
DTC9 Control Unit Abnormality 3F±28. . . . . . . . . . . .
Control Unit 3F±32. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 3F±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 3F±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Actuator 3F±34. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 3F±35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 3F±35. . . . . . . . . . . . . . . . . . . .
Installation 3F±35. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Shock Absorber 3F±36. . . . . . . . . . . . . . . . . . . .
Removal 3F±37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 3F±37. . . . . . . . . . . . . . . . . . . .
Installation 3F±37. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3F±8INTELLIGENT SUSPENSION
INTERMITTENT CONDITIONS
If the Warning Lamp flashes a diagnostic trouble code as
intermittent, or if after a test drive a DTC does not
reappear though the detection conditions for this DTC are
present: the problem is most likely a faulty electrical
connection or loose wiring. Terminals and grounds should
always be the prime suspect. Intermittents rarely occur
inside sophisticated electronic components such as the
Control Unit.
Use the DTC information to understand which wires and
sensors are involved.
When an intermittent problem is encountered, check
suspect circuits for:
1. Poor terminal to wire connection.
2. Terminals not fully seated in the connector body
(backed out).
3. Improperly formed or damaged terminals.
4. Loose, dirty, or corroded ground connections:
HINT: Any time you have an intermittent in more than
one circuit, check whether the circuits share a
common ground connection.
5. Pinched or damaged wires.
6. Electro-Magnetic Interference (EMI):
HINT: Check that all wires are properly routed away
from spark plug wires, distributor wires, coil, and
generator. Also check for improperly installed
electrical options, such as lights, 2-way radios, etc.
BULB CHECK
When the starter switch is turned on in the normal state,
the Control Unit turns on the Warning Lamp to check the
bulb. After the engine starts, the Warning Lamp turns off.
F03RY00003
DTC CHECK
1. Diagnosis Trouble Codes (DTC) have been identified
by FLASHING CODES.
2. You have written the list of the DTC. The order of the
malfunctions has no meanings for this Control Unit.
Usually only one or two malfunctions should be set for
a given problem.
3. Check directly the DTCs you identified. The DTC are
sorted by number:
DIAGNOSTIC TROUBLE CODES.

INTELLIGENT SUSPENSION3F±23
DTC5 Vehicle Speed Sensor Open Circuit or Short
Circuit Description
Output speed information is provided to the control unit by
the vehicle speed sensor. The vehicle speed sensor
produces a pulsing AC voltage. The AC voltage level and
number of pulses increases as the speed of the vehicle
increases. The control unit then converts the pulsing
voltage to vehicle speed.
Diagnostic Aids

Inspect the wiring for poor electrical connections
between the control unit 48 way connector and the
speed sensor connectors. Look for possible bent,
backed out, deformed, or damaged terminals. Check
for weak terminal tension as well.
Also check for a chafed wire that could short to bare
metal or other wiring. Inspect for a broken wire inside
the insulation.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.
DTC5 Vehicle Speed Sensor Open Circuit or Short
StepActionValue(s)Ye sNo
11. Jack up and support the rear axle on the stand.
2. Change the transfer mode to 2WD, using TOD
switch on instrument panel.
3. Shift the transmission lever in a forward position
and rotate the rear wheels.
Does the speedo-meter operate?
ÐGo to Step 2Go to Step 3
21. Open the throttle and rev up engine speed.
2. Using a volt meter, measure the voltage between
the meter B connector I±23 terminals 7 and 16
(GND).
Does the voltage change alternately at the specified
values?
0V and 12VGo to Step 7Go to Step 5
31. Turn off the starter switch and disconnect the
control connectors C±46 and C±44.
2. Check the continuity between the vehicle speed
sensor connector terminal 3 and meter B connector
I±23 terminal 7.
Is there continuity?
ÐGo to Step 4Go to Step 6
41. Check the continuity between the control unit
connector C±46 terminal 1 and control unit
connector C±44 terminal 48.
Is there continuity?
ÐGo to Step 5Go to Step 6
5Repair or replace the vehicle speed sensor.
ÐGo to Step 8Ð
6Repair the circuit between the vehicle speed sensor
connector terminal 3 and the meter B connector I±23
terminal 7 or the circuit between the control unit
connector C±44 terminal 48 and the speed sensor
connector terminal 3.
ÐGo to Step 8Ð

INTELLIGENT SUSPENSION3F±25
DTC6 Stop Lamp Switch Open Circuit or Short
Circuit Description
The brake switch is used to indicate brake pedal status.
The normally opened brake switch signal voltage circuit is
opened.
Brake switch supplies a B+ signal on circuit RED to the
control unit when the brakes are applied. The control unit
uses this signal to work dive control when the brakes are
applied.
Diagnostic Aids

Inspect the wiring for poor electrical connections at
the control unit and brake switch. Look for possible
bent, backed out, deformed or damaged terminals.
Check for weak terminal tension as well. Also check
for a chafed wire that could short to bare metal or
other wiring. Inspect for a broken wire inside the
insulation.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.

Check customer driving habits and/or unusual driving
conditions (i.e. stop and go, highway).

Check brake switch for proper mounting and
adjustment.
DTC6 Stop Lamp Switch Open Circuit or Short
StepActionValue(s)Ye sNo
11. With the engine ªoffº, turn the ignition switch ªonº. If
ABS code is set, check applicable fuse.
2. Apply then release the brake pedal.
Does the brake lamp come on when the brake pedal is
applied and does it come off when the brake pedal is
released?
Ð
Go to
Diagnostic
Aids
Go to Step 2
21. Connect the test light to ground.
2. Back probe ignition feed circuit terminal I±31
terminal 1 at the brake switch.
Is the test light ªonº?
ÐGo to Step 3Go to Step 4
31. Connect the test light to ground.
2. Back probe circuit terminal I±31 terminal 4 at the
brake switch.
Is the test light ªoffº?
ÐGo to Step 7Go to Step 5
4Repair the open in battery feed circuit terminal I±31
terminal 1 to the brake switch.
If fuse is open, check circuit terminal I±31 terminal 4 for
a short to ground.
Is the replacement complete?
ÐGo to Step 13Ð
5Disconnect brake switch connector I±31 and ignition
switch ªonº.
Is the test light ªonº?
ÐGo to Step 8Go to Step 6
6Check the brake switch short (I±31 terminal 1 and I±31
terminal 4).
Was a problem found?
ÐGo to Step 9Go to Step 10
7Check circuit terminal I±31 terminal 4 for a short to
voltage.
Ignition switch ªonº.
Is the test light ªonº?
ÐGo to Step 8Go to Step 10
81. Disconnect the control unit connector C±44.
2. Check circuit terminal I±31 terminal 4 for a short to
voltage.
Was a problem found?
ÐGo to Step 13Go to Step 10

INTELLIGENT SUSPENSION3F±27
DTC7 Engine Speed Signal Open Circuit or Short
Circuit Description
PCM (Powertrain Control Module) converts signals from
the crankshaft position sensor into the engine speed
signals (pulse) and sends these to the control unit and
tachometer.
Diagnostic Aids

Inspect the wiring for poor electrical connections at
the control unit connector. Look for possible bent,
backed out, deformed, or damaged terminals. Check
for weak terminal tension as well.
Also check for a chafed wire that could short to bare
metal or other wiring. Inspect for a broken wire inside
the insulation.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.

Check harness routing for a potential short to ground
in circuit BLK/RED.
DTC7 Engine Speed Signal Open Circuit or Short
StepActionValue(s)Ye sNo
1NOTE: Confirm that DTC P0336 or P0337 does not
exist.
If either exists, warning lamps, ªCHECK ENGINEº and
ªCHECK TRANSº are turned on. Repair the engine,
referring to section 6E
Driveability and Emission.
1. Turn on the starter switch.
2. Start the engine.
3. Open the throttle and rev up engine speed.
Does the tachometer operate according to engine
speed?
ÐGo to Step 3Go to Step 2
2Repair the tachometer, referring to section 8D Wiring
System in Body and Accessories
.
ÐGo to Step 6Ð
31. Turn off the starter switch.
2. Check continuity between the control unit connector
C±44 terminal 59 and PCM connector E±34
terminal F7.
Is there continuity ?
ÐGo to Step 4Go to Step 5
4Replace the control unit.
ÐGo to Step 6Ð
5Repair the circuit.
ÐGo to Step 6Ð
61. Reconnect all components, ensure all components
are properly mounted.
2. Clear the DTC.
3. Conduct a test drive.
Has the last test failed or does the current DTC exist?
Ð
Begin diagnosis
again
Go to
Step 1
Repair
verified

DIFFERENTIAL (REAR)4A2±3
Diagnosis
Many noises that seem to come from the rear axle
actually originate from other sources such as tires, road
surface, wheel bearings, engine, transmission, muffler, or
body drumming. Investigate to find the source of the
noise before disassembling the rear axle. Rear axles, like
any other mechanical device, are not absolutely quiet but
should be considered quiet unless some abnormal noise
is present.
To make a systematic check for axle noise, observe the
following:
1. Select a level asphalt road to reduce tire noise and
body drumming.
2. Check rear axle lubricant level to assure correct level,
and then drive the vehicle far enough to thoroughly
warm up the rear axle lubricant.
3. Note the speed at which noise occurs. Stop the
vehicle and put the transmission in neutral. Run the
engine speed slowly up and down to determine if the
noise is caused by exhaust, muffler noise, or other
engine conditions.
4. Tire noise changes with different road surfaces; axle
noises do not. Temporarily inflate all tires to 344 kPa
(50 psi) (for test purposes only). This will change
noise caused by tires but will not affect noise caused
by the rear axle.
Rear axle nose usually stops when coasting at
speeds under 48 km/h (30 mph); however, tire noise
continues with a lower tone. Rear axle noise usually
changes when comparing pull and coast, but tire
noise stays about the same.
Distinguish between tire noise and rear axle noise by
noting if the noise changes with various speeds or
sudden acceleration and deceleration. Exhaust and
axle noise vary under these conditions, while tire
noise remains constant and is more pronounced at
speeds of 32 to 48 km/h (20 to 30 mph). Further check
for tire noise by driving the vehicle over smooth
pavements or dirt roads (not gravel) with the tires at
normal pressure. If the noise is caused by tires, it will
change noticeably with changes in road surface.
5. Loose or rough front wheel bearings will cause noise
which may be confused with rear axle noise; however,
front wheel bearing noise does not change when
comparing drive and coast. Light application of the
brake while holding vehicle speed steady will often
cause wheel bearing noise to diminish. Front wheel
bearings may be checked for noise by jacking up the
wheels and spinning them or by shaking the wheels to
determine if bearings are loose.
6. Rear suspension rubber bushings and spring
insulators dampen out rear axle noise when correctly
installed. Check to see that there is no link or rod
loosened or metal±to±metal contact.7. Make sure that there is no metal±to±metal contact
between the floor and the frame.
After the noise has been determined to be in the axle, the
type of axle noise should be determined, in order to make
any necessary repairs.
Gear Noise
Gear noise (whine) is audible from 32 to 89 km/h (20 to 55
mph) under four driving conditions.
1. In drive under acceleration or heavy pull.
2. Driving under load or under constant speed.
3. When using enough throttle to keep the vehicle from
driving the engine while the vehicle slows down
gradually (engine still pulls slightly).
4. When coasting with the vehicle in gear and the throttle
closed. The gear noise is usually more noticeable
between 48 and 64 km/h (30 and 40 mph) and 80 and
89 km/h (50 and 55 mph).
Bearing Noise
Bad bearings generally produce a rough growl or grating
sound, rather than the whine typical of gear noise.
Bearing noise frequently ªwow±wowsº at bearing rpm,
indicating a bad pinion or rear axle side bearing. This
noise can be confused with rear wheel bearing noise.
Rear Wheel Bearing Noise
Rear wheel bearing noise continues to be heard while
coasting at low speed with transmission in the neutral.
Noise may diminish by gentle braking. Jack up the rear
wheels, spin them by hand and listen for noise at the
hubs. Replace any faulty wheel bearings.
Knock At Low Speeds
Low speed knock can be caused by worn universal joints
or a side gear hub counter bore in the cage that is worn
oversize. Inspect and replace universal joints or cage and
side gears as required.
Backlash Clunk
Excessive clunk on acceleration and deceleration can be
caused by a worn rear axle pinion shaft, a worn cage,
excessive clearance between the axle and the side gear
splines, excessive clearance between the side gear hub
and the counterbore in the cage, worn pinion and side
gear teeth, worn thrust washers, or excessive drive pinion
and ring gear backlash. Remove worn parts and replace
as required. Select close±fitting parts when possible.
Adjust pinion and ring gear backlash.

4B2±15
DRIVE LINE CONTROL SYSTEM (TOD)
Indication Method of Trouble Code

Turn on the starter switch, while the engine does not
start.

Short-circuit terminal 8 of the self-diagnostic
connector to GND (terminal 4 or 5) to display the
trouble code on the CHECK lamp.
826R200011

If no trouble codes exist, code ª12º is displayed
continuously.

If trouble codes exist, code ª12º is displayed three
times, and the trouble codes, starting from the smaller
code number, are displayed three times respectively.
C07RY00018