ABS INFINITI QX56 2004 Factory Service Manual

CHASSIS AND BODY MAINTENANCE
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Revision: August 20072004 QX56
Checking Power Steering Fluid and LinesELS0010U
CHECKING FLUID LEVEL

Check the power steering fluid level with the engine off.

Check fluid level on reservoir. Use “HOT” range at fluid tempera-
tures of 50° to 80°C (122° to 176°F). Use “COLD” range at fluid
temperatures of 0° to 30°C (32° to 86°F).
CAUTION:

Do not overfill.

Refer to MA-10, "Fluids and Lubricants" .
CHECKING LINES

Check lines for improper attachment, leaks, cracks, damage,
loose connections, chafing and deterioration.
Checking Axle and Suspension PartsELS0010V
FRONT AND REAR AXLE AND SUSPENSION PARTS
Check front and rear axle and suspension parts for excessive play, cracks, wear or other damage.

Shake each wheel to check for excessive play.

Rotate each wheel to check for abnormal noise.

Check axle and suspension nuts and bolts for looseness.

Check the strut and shock absorber for oil leakage or other damage.

Check suspension ball joints for grease leakage and ball joint dust cover for cracks or other damage.
DRIVE SHAFT
Check the boots and drive shaft for cracks, wear, damage, and
grease leakage.
LGIA0021E
SGIA0506E
SM A52 5A
SFA90 1

PB-6
PARKING BRAKE SHOE
Revision: August 20072004 QX56
PARKING BRAKE SHOEPFP:44060
Removal and InstallationEFS003Q7
COMPONENTS
REMOVAL
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Clean the brakes with a vacuum dust collector to minimize the hazard of airborne particles or other
materials.
NOTE:
Remove the disc rotor only with the parking brake pedal completely disengaged.
1. Remove the rear disc rotor. Refer to BR-28, "
Removal and Installation of Brake Caliper Assembly and
Disc Rotor" .
2. Remove the rear drive shaft. Refer to RAX-7, "
Removal and Installation" .
3. Disconnect ABS sensor at harness connector. Then remove ABS sensor wire from grommet mounts.
4. Remove wheel hub and bearing assembly. Refer to RAX-5, "
Removal and Installation" .

Withdraw ABS sensor harness through back plate when removing wheel hub and bearing assembly.
5. Remove the return springs.
6. Remove the adjuster.
7. Remove the retainers, anti-rattle pins and shoes.
8. Disconnect the parking brake cable from the toggle lever.
9. Remove back plate.
1. Back plate 2. Shoes 3. Toggle lever
4. Return springs 5. Retainers 6. Adjuster
7. Anti-rattle pins
WFIA0164E

WHEEL HUB
RAX-5
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WHEEL HUBPFP:43202
On-Vehicle Inspection and ServiceEDS001AT
Inspect the components for any looseness or back lash. Inspect each component for any excessive wear or
damage. Replace any components as necessary.
WHEEL BEARING INSPECTION

Move the wheel hub and bearing assembly in the axial direction by hand to check the axial end play.
Check that the axial end play is with specification. Replace the wheel hub and bearing assembly as nec-
essary.

Rotate the wheel hub and bearing assembly to check that there are no unusual noises or other abnormal
conditions. Replace the wheel hub and bearing assembly as necessary.
Removal and InstallationEDS001AU
Rear Wheel Hub and Bearing Assembly
NOTE:
The rear ABS sensor is routed through the back of the rear backing plate and into the side of the wheel hub
and bearing assembly. It is necessary to remove the wheel hub and bearing assembly to remove the rear ABS
sensor.
REMOVAL
1. Remove the wheel and tire using power tool.
2. Remove the rear brake caliper, without disconnecting the hydraulic hose, using power tool. Reposition the
rear brake caliper aside using suitable wire. Refer to BR-28, "
Removal and Installation of Brake Caliper
Assembly and Disc Rotor" .
NOTE:

Do not depress the brake pedal while the brake caliper is removed.
3. Remove the rear disc rotor.Axial end play : 0 mm (0 in)
WDIA0300E
1. Back plate 2. Rear ABS sensor 3. Wheel hub and bearing assembly
4. Wheel stud 5. Rear disc rotor 6. Cotter pin
⇐: Vehicle front

RAX-6
WHEEL HUB
Revision: August 20072004 QX56
4. Remove the cotter pin, then remove the nut from the drive shaft
using power tool.

Discard the cotter pin, use a new one for installation.
5. Remove the drive shaft. Refer to RAX-7, "
Removal and Installa-
tion" .
6. Remove the four wheel hub and bearing assembly bolts using power tool.

Discard the four wheel hub and bearing assembly bolts, use new ones for installation.
7. Pull out the wheel hub and bearing assembly for access to
remove the rear ABS sensor from the wheel hub and bearing
assembly as shown.

Inspect the ABS sensor O-ring, replace the ABS sensor
assembly if damaged.

Clean the ABS sensor hole and mounting surface with a suit-
able brake cleaner and a clean lint-free shop rag. Be careful
that dirt and debris do not enter the axle bearing area.

Apply a coat of suitable grease to the ABS sensor O-ring and
mounting hole.
CAUTION:
Do not pull on the ABS harness.
8. Remove the wheel hub and bearing assembly.
INSTALLATION
Installation is in the reverse order of removal.

Apply grease 44003 7S000CM to contact surface (A) between
wheel hub and bearing assembly and drive shaft as shown. Use
sufficient grease to completely coat contact area.

Inspect the ABS sensor O-ring, replace the ABS sensor assem-
bly if damaged.

Clean the ABS sensor hole and mounting surface with a suitable
brake cleaner and a clean lint-free shop rag. Be careful that dirt
and debris do not enter the axle bearing area.

Apply a coat of suitable grease to the ABS sensor O-ring and
mounting hole.

Use a new cotter pin for installation.

Use new wheel hub and bearing assembly bolts for installation.
LDIA0050E
LDIA0052E
WDIA0299E

RSU-1
REAR SUSPENSION
E SUSPENSION
CONTENTS
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SECTION RSU
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RSU
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions for Rear Suspension ............................ 3
Wiring Diagrams and Trouble Diagnosis .................. 3
PREPARATION ........................................................... 4
Commercial Service Tools ........................................ 4
NOISE, VIBRATION, AND HARSHNESS (NVH)
TROUBLESHOOTING ................................................ 5
NVH Troubleshooting Chart ..................................... 5
CAN COMMUNICATION ............................................ 6
System Description .................................................. 6
TROUBLE DIAGNOSIS .............................................. 7
How to Perform Trouble Diagnoses for Quick and
Accurate Repair ....................................................... 7
INTRODUCTION ................................................... 7
CLARIFY CONCERN ............................................ 7
WORK FLOW ........................................................ 8
Component Parts and Harness Connector Location ..... 9
Wiring Diagram — A/SUSP — ............................... 10
Basic Inspection ..................................................... 12
AIR HOSES ......................................................... 12
POWER SYSTEM TERMINAL LOOSENESS
AND BATTERY INSPECTION ............................ 12
CK SUSP INDICATOR LAMP INSPECTION ...... 12
CK SUSP Indicator Lamp Timing ........................... 12
Control Unit Input/Output Signal Standard ............. 12
CONSULT-II Function (AIR LEVELIZER) ............... 13
CONSULT-II OPERATION .................................. 13
WORK SUPPORT ............................................... 14
SELF-DIAGNOSIS .............................................. 14
DATA MONITOR ................................................. 15
ACTIVE TEST ..................................................... 16
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ....................................................................... 17
Height Sensor System Inspection .......................... 17
Exhaust Valve Solenoid System Inspection ........... 19
Compressor Motor, Compressor Motor Relay and Circuit Inspection .................................................... 20
TROUBLE DIAGNOSES FOR SYMPTOMS ............ 23
Load Leveling Rear Air Suspension System Does
Not Operate ............................................................ 23
CK SUSP Indicator Lamp Stays On When Ignition
Switch Is Turned On ............................................... 24
REAR SUSPENSION ASSEMBLY ........................... 25
Components ........................................................... 25
On-Vehicle Inspection and Service ......................... 26
SHOCK ABSORBER INSPECTION .................... 26
Wheel Alignment Inspection ................................... 27
PRELIMINARY INSPECTION ............................. 27
GENERAL INFORMATION AND RECOMMEN-
DATIONS ............................................................. 27
THE ALIGNMENT PROCESS ............................. 28
CAMBER ............................................................. 28
TOE-IN ................................................................ 28
REAR SUSPENSION MEMBER ............................... 30
Removal and Installation ........................................ 30
REMOVAL ........................................................... 31
INSPECTION AFTER REMOVAL ....................... 32
INSTALLATION ................................................... 33
SHOCK ABSORBER ................................................ 34
Removal and Installation ........................................ 34
REMOVAL ........................................................... 34
INSTALLATION ................................................... 34
INSPECTION AFTER INSTALLATION ................ 34
SUSPENSION ARM .................................................. 35
Removal and Installation ........................................ 35
REMOVAL ........................................................... 35
INSPECTION AFTER REMOVAL ....................... 35
INSTALLATION ................................................... 36
FRONT LOWER LINK .............................................. 37
Removal and Installation ........................................ 37
REMOVAL ........................................................... 37
INSPECTION AFTER REMOVAL ....................... 37
INSTALLATION ................................................... 38

NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTING
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Revision: August 20072004 QX56
NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTINGPFP:00003
NVH Troubleshooting ChartEES00111
Use chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.
×: Applicable Reference page
RSU-25RSU-34
—
—
—
RSU-25
RSU-27RSU-41
PR-3, "
NVH Troubleshooting Chart
"
RFD-5, "
NVH Troubleshooting Chart
"
FAX -4, "
NVH Troubleshooting Chart
" (FAX)
FSU-4, "
NVH Troubleshooting Chart
" (FSU)
WT-3, "
NVH Troubleshooting Chart
"
WT-3, "
NVH Troubleshooting Chart
"
RAX-4, "
NVH Troubleshooting Chart
"
PS-5, "
NVH Troubleshooting Chart
"
BR-5, "
NVH Troubleshooting Chart
"
Possible cause and SUSPECTED PARTS
Improper installation, looseness
Shock absorber deformation, damage or deflection
Bushing or mounting deterioration
Parts interference
Spring fatigue
Suspension looseness
Incorrect wheel alignment
Stabilizer bar fatigue
PROPELLER SHAFT
DIFFERENTIAL
FRONT AXLE AND FRONT SUSPENSION
TIRES
ROAD WHEEL
DRIVE SHAFT
BRAKES
STEERING
SymptomNoise×××××× ××× ×××××
Shake×××× × × × ×××××
Vibration××××× × × × × ×
Shimmy×××× × × ×× ××
Shudder ××× × ×× ××
Poor quality ride or handling××××× ×× × ××

RSU-12
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Basic InspectionEES00116
AIR HOSES
1. Check for pinched or damaged air hoses between the suspension air reservoir and each load leveling rear
air suspension shock absorber. Reposition, repair or replace hoses as necessary.
2. Check the air hose connections at the suspension air reservoir and at the shock absorbers for leaks. If
connections are leaking, repair or replace hoses as necessary.
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION
Make sure the battery positive cable, negative cable and ground connection are not loose. In addition, make
sure the battery is sufficiently charged.
CK SUSP INDICATOR LAMP INSPECTION
1. Make sure the CK SUSP indicator lamp turns on for approximately 2 seconds when the ignition switch is
turned ON. If it does not, check the combination meter. Refer to DI-5, "
COMBINATION METERS" .
2. Make sure the lamp turns off approximately 2 seconds after the ignition switch is turned ON. If the lamp
does not turn off, conduct self-diagnosis of the suspension control unit.
3. After conducting the self-diagnosis, be sure to erase the error memory. Refer to RSU-13, "
CONSULT-II
Function (AIR LEVELIZER)" .
CK SUSP Indicator Lamp TimingEES00117
X: ON
—: OFF
Control Unit Input/Output Signal StandardEES00118
( ): Wire colorConditionCK SUSP
indicator lampRemarks
Ignition switch OFF – –
Ignition switch ON X Turns off after approximately 2 seconds.
Te r m i n a l
Item ConditionVoltage (V)
(Approx.)
+–
1 (V)
GroundCompressor relay output
Ignition switch ON or STARTBattery voltage
3 (W) Height sensor signal input 0.2V - 4.8V
5 (R) Reference voltage 5V
6 (G/R) Ignition power
Battery voltage
7 (W/L) Battery power —
8 (G/W) Diagnostic K-line — —
9 (SB) Exhaust valve output Ignition switch ON or START Battery voltage
10 (BR) Warning lamp output — —
14 (L) Height sensor ground — —
15 (BR/W) Alternator L signal input Engine running —
16 (B) Suspension control unit ground — 0V

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
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Revision: August 20072004 QX56
Exhaust Valve Solenoid System InspectionEES0011B
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> If code C1803 was retrieved during self-diagnosis, GO TO 3. If code C1805 was retrieved during
self-diagnosis, GO TO 2.
NO >> Inspection End.
2. CHECK SYSTEM OPERATION
1. Load vehicle to standard laden condition (with driver, front passenger, 2 passengers in second row seats
and no cargo).
2. Conduct active test of "COMPRESSOR" to raise vehicle ride height to +20mm.
CAUTION:
The "COMPRESSOR" active test will remain ON until it is turned off using CONSULT-II. Allowing
the compressor to run for an extended period of time may cause damage to air suspension sys-
tem components due to excessive pressure in the air suspension system.
3. Return the rear load leveling air suspension system to normal operating mode.
4. Check self-diagnostic results.
Is code C1805 displayed again?
YES >> GO TO 3.
NO >> Inspection End.
3. CONNECTOR INSPECTION
1. Turn ignition switch OFF.
2. Disconnect suspension control unit connector B3 and suspension air compressor C9.
3. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> If code C1805 was retrieved during self-diagnosis, GO TO 4. If code C1803 was retrieved during
self-diagnosis, GO TO 6.
NG >> Repair or replace as necessary.
4. AIR HOSE INSPECTION
Inspect for pinched or damaged air hoses between the suspension air reservoir and each load leveling rear air
suspension shock absorber.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace as necessary.
Self-diagnosis results
C1803
C1805

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
RSU-21
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Revision: August 20072004 QX56
2. CHECK SYSTEM OPERATION
1. Load vehicle to standard laden condition (with driver, front passenger, 2 passengers in second row seats
and no cargo).
2. Conduct active test of "EXHAUST SOLENOID" to lower vehicle ride height to -20mm.
3. Return the rear load leveling air suspension system to normal operating mode.
4. Check self-diagnostic results.
Is code C1804 or C1808 displayed again?
YES >> GO TO 3.
NO >> Inspection End.
3. CONNECTOR INSPECTION
1. Turn ignition switch OFF.
2. Disconnect suspension control unit connector B3 and suspension air compressor C9.
3. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> If code C1804 or C1808 was retrieved during self-diagnosis, GO TO 4. If code C1802 was
retrieved during self-diagnosis, GO TO 6.
NG >> Repair or replace as necessary.
4. AIR HOSE INSPECTION
Inspect for pinched or damaged air hoses between the suspension air reservoir and each load leveling rear air
suspension shock absorber.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace as necessary.
5. SUSPENSION AIR COMPRESSOR INSPECTION
Apply 12V to suspension air compressor C9 terminal 2 and body
ground to suspension air compressor C9 terminal 1.
OK or NG
OK >> GO TO 6.
NG >> Replace the suspension air compressor. Refer to RSU-
42, "REAR LOAD LEVELING AIR SUSPENSION COM-
PRESSOR ASSEMBLY" . System air pressure should vent.
WEIA0066E

RSU-26
REAR SUSPENSION ASSEMBLY
Revision: August 20072004 QX56
Rear Load Leveling Air Suspension System
On-Vehicle Inspection and ServiceEES0011G
Check all of the component mountings for any excessive looseness, or back lash. Check the components for
any excessive wear, damage, or abnormal conditions. Repair or replace the components as necessary.
SHOCK ABSORBER INSPECTION

Check the shock absorbers for any air leaks or damage, and replace as necessary.

Check the hoses for any air leaks or damage, and replace as necessary.
1. Seat belt latch anchor 2. Stabilizer bar bushing 3. Stabilizer bar clamp
4. Stabilizer bar 5. Connecting rod 6. Front lower link
7. Knuckle 8. Bushing 9. Rear lower link
10. Shock absorber 11. Suspension arm 12. Lower rubber seat
13. Coil spring 14. Upper rubber seat 15. Rear suspension member
16. Spare tire bracket 17. Bound bumper
LEIA0072E
1. Rear load leveling air suspension
hose, RH2. Shock absorber, RH 3. Height sensor
4. Rear load leveling air suspension
hose, LH5. Shock absorber, LH 6. Rear load leveling air suspension
compressor assembly