2004 INFINITI QX56 height

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

REAR SUSPENSION ASSEMBLY
RSU-27
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Revision: August 20072004 QX56
Wheel Alignment InspectionEES0011H
Rear Wheel Alignment Adjusting Bolts
PRELIMINARY INSPECTION
WA RN ING:
Always adjust the alignment with the vehicle on a flat surface. Use CONSULT-II "EXHAUST SOLE-
NOID" active test to release the air pressure from the rear load leveling air suspension system.
NOTE:
If alignment is out of specification, inspect and replace any damaged or worn rear suspension parts before
making any adjustments.
1. Check and adjust the wheel alignment with the vehicle under unladen conditions. “Unladen conditions”
means that the fuel, coolant, and lubricant are full; and that the spare tire, jack, hand tools and mats are in
their designated positions.
2. Check the tires for incorrect air pressure and excessive wear.
3. Check the wheels for runout and damage. Refer to WT-4, "
Inspection" .
4. Check the wheel bearing axial end play.
5. Check the shock absorbers. Refer to RSU-26, "
SHOCK ABSORBER INSPECTION" .
6. Check each mounting point of the suspension components for any excessive looseness or damage.
7. Check each link, arm, and the rear suspension member for any damage.
8. Check the vehicle height. Refer to RSU-48, "
Wheelarch Height (Unladen*1 )" .

Verify the vehicle height using Consult-II memory register 1103 and set to 0 ± 10 mm (0 ± 0.39 in) as
necessary.
GENERAL INFORMATION AND RECOMMENDATIONS
1. A Four-Wheel Thrust Alignment should be performed.

This type of alignment is recommended for any NISSAN vehicle.

The four-wheel “thrust” process helps ensure that the vehicle is properly aligned and the steering wheel
is centered.

The alignment machine itself should be capable of accepting any NISSAN vehicle.

The alignment machine should be checked to ensure that it is level.
2. Make sure the alignment machine is properly calibrated.

Your alignment machine should be regularly calibrated in order to give correct information.
WEIA0102E
1. Rear lower link adjusting bolt, LH 2. Front lower link adjusting bolt, LH 3. Front lower link adjusting bolt, RH
4. Rear lower link adjusting bolt, RH
Axial end play : 0 mm (0 in)

RSU-28
REAR SUSPENSION ASSEMBLY
Revision: August 20072004 QX56

Check with the manufacturer of your specific alignment machine for their recommended Service/Cali-
bration Schedule.
THE ALIGNMENT PROCESS
IMPORTANT: Use only the alignment specifications listed in this Service Manual. Refer to RSU-47, "Wheel
Alignment" .
1. When displaying the alignment settings, many alignment machines use “indicators”: (Green/red, plus or
minus, Go/No Go). Do NOT use these indicators.

The alignment specifications programmed into your alignment machine that operate these indicators
may not be correct.

This may result in an ERROR.
2. Some newer alignment machines are equipped with an optional “Rolling Compensation” method to “com-
pensate” the sensors (alignment targets or head units). Do NOT use this “Rolling Compensation”
method.

Use the “Jacking Compensation” method. After installing the alignment targets or head units, raise the
vehicle and rotate the wheels 1/2 turn both ways.

See Instructions in the alignment machine you are using for more information.
CAMBER
1. Measure camber of both the right and left wheels with a suitable
alignment gauge and adjust as necessary to specification.
2. If outside of the specified value, adjust the camber using the
adjusting bolt in the front lower link.
CAUTION:
After adjusting the camber then check the toe-in.
NOTE:
Camber changes about 5' minutes with each graduation of the
adjusting bolt.
3. Tighten the adjusting bolt nuts to specification.
TOE-IN
1. Bounce the rear of the vehicle up and down two to three times to stabilize the vehicle height. Refer to
RSU-48, "
Wheelarch Height (Unladen*1 )" .
2. Push the vehicle straight ahead about 5 m (16 ft).
3. Put a mark on the base line of the tread (rear side) of both of the
tires at the same height as the center of the hub. This will be the
measuring points.
4. Measure the distance “A” (rear side) across from tire to tire.Camber : Refer to RSU-47, "
Wheel Alignment" .
SRA0 96 A
LEIA0041E
SFA614B

REAR SUSPENSION MEMBER
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Revision: August 20072004 QX56
Rear Load Leveling Air Suspension System
REMOVAL
1. Use the CONSULT-II “EXHAUST SOLENOID” active test to release the air pressure from the rear load
leveling air suspension system.
2. Disconnect the electrical connectors for the height sensor and the rear load leveling air suspension com-
pressor assembly.
3. Unclip the rubber cover to access the rear load leveling air suspension compressor assembly.
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 (includes the
bracket and rubber cover)

RSU-32
REAR SUSPENSION MEMBER
Revision: August 20072004 QX56
4. Disconnect the rear load leveling air suspension hoses at the
rear load leveling air suspension compressor assembly.

To disconnect the hoses, push in on the lock ring using a suit-
able tool and pull the hose out.
5. Remove both of the rear wheel and tire assemblies using power
tool.
6. Remove the brake caliper without disconnecting the brake
hoses, using power tool. Reposition the brake caliper out of the
way using a suitable wire. Refer to BR-28, "
Removal and Instal-
lation of Brake Caliper Assembly and Disc Rotor" .
CAUTION:

Do not crimp or stretch the brake hose when repositioning the brake caliper out of the way.

Do not press brake pedal while the brake caliper is removed.
7. Remove the spare tire.
8. Disconnect the two rear ABS sensor electrical connectors.
9. Remove the two rear drive shafts. Refer to RAX-7, "
Removal and Installation" .
10. Remove the rear final drive. Refer to RFD-10, "
REAR FINAL DRIVE ASSEMBLY" .
11. Remove the EVAP canister bolt from the top of the rear suspension member.
12. Disconnect the parking brake cables from the brackets on the rear suspension member.
13. Set a suitable jack to support each of the rear lower links and the
coil spring tension.
14. Remove both of the rear lower link outer bolts and lower the jack to remove the rear coil springs.
15. Remove the two bolts to disconnect the seat belt latch anchor
from the rear suspension member.
16. Disconnect both of the connecting rods from the rear stabilizer
bar.
17. Set a suitable jack under the rear suspension member.
18. Remove the six rear suspension member bolts.
19. Slowly lower the jack to remove the rear suspension member,
suspension arm, front and rear lower links and stabilizer bar as
an assembly.
20. If necessary, remove the suspension arm, spare tire bracket,
height sensor, rear load leveling air suspension hoses, stabilizer
bar, knuckle, and front and rear lower links from the rear suspension member.
INSPECTION AFTER REMOVAL
Check the rear suspension member for deformation, cracks, and other damage and replace if necessary.
LEIA0074E
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LEIA0075E

REAR LOWER LINK & COIL SPRING
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Revision: August 20072004 QX56
REAR LOWER LINK & COIL SPRINGPFP:551B0
Removal and Installation EES0011P
REMOVAL
1. Remove the wheel and tire assembly using power tool. Refer to WT-6, "Rotation" .
2. Use CONSULT-II "EXHAUST SOLENOID" active test to release the air pressure from the rear load level-
ing air suspension system.
3. For removing the LH rear lower link and coil spring, remove the
height sensor arm bracket bolt from the LH rear lower link.
4. Set a suitable jack to relieve the coil spring tension from the rear
lower link.
WAR NIN G:
Do not compress the coil spring when setting the jack.
5. Loosen the rear lower link adjusting bolt and nut connected to
the rear suspension member, using power tool.
6. Remove the rear lower link bolt and nut from the knuckle using
power tool.
7. Slowly lower the suitable jack to release the coil spring tension. Then remove the upper rubber seat, coil
spring, and lower rubber seat from the rear lower link.
LEIA0080E
LEIA0077E
LEIA0009E
LEIA0077E

RSU-42
REAR LOAD LEVELING AIR SUSPENSION COMPRESSOR ASSEMBLY
Revision: August 20072004 QX56
REAR LOAD LEVELING AIR SUSPENSION COMPRESSOR ASSEMBLYPFP:53400
Removal and InstallationEES0011T
Rear Load Leveling Air Suspension System
REMOVAL
1. Use CONSULT-II "EXHAUST SOLENOID" active test to release the air pressure from the rear load level-
ing air suspension system.
2. Disconnect the electrical connectors for the rear load leveling air suspension compressor assembly.
3. Unclip the rubber cover to access the rear load leveling air suspension compressor assembly.
4. Disconnect the rear load leveling air suspension hoses at the
rear load leveling air suspension compressor assembly.

To disconnect the hoses, push in on the lock ring using a suit-
able tool and pull the hose out.
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
LEIA0074E