2004 INFINITI QX56 Ins

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
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TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSPFP:00000
Height Sensor System InspectionEES0011A
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 3.
NO >> GO TO 2.
2. DATA MONITOR CHECK
Conduct data monitor of "HEIGT SEN" to check if the status is normal.
OK or NG
OK >> Inspection End.
NG >> GO TO 3.
3. CONNECTOR INSPECTION
1. Turn ignition switch OFF.
2. Disconnect suspension control unit connector B3 and height sensor C8.
3. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace as necessary.
Self-diagnosis results
C1801
C1806
C1807
HEIGT SEN 0.2V - 4.8V

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
RSU-19
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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

RSU-20
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
5. EXHAUST VALVE SOLENOID 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" .
6. CHECK EXHAUST VALVE SOLENOID POWER AND GROUND
1. Reconnect the suspension control unit connector.
2. Turn the ignition switch ON.
3. Check voltage between suspension air compressor connector
C9 terminal 2 (SB) and ground.
4. Turn ignition switch OFF.
5. Check resistance between suspension air compressor connec-
tor C9 terminal 1 (B) and ground.
OK or NG
OK >> Replace the suspension control unit. Refer to RSU-46,
"CONTROL UNIT" .
NG >> Repair the circuit.
Compressor Motor, Compressor Motor Relay and Circuit InspectionEES0011C
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> If code C1802 was retrieved during self-diagnosis, GO TO 3. If code C1804 or C1808 was
retrieved during self-diagnosis, GO TO 2.
NO >> Inspection End.System air pressure should vent.
WEIA0063E
Voltage : Approx. 12V
WEIA0088E
Continuity should exist.
WEIA0089E
Self-diagnosis results
C1802
C1804
C1808

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
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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

TROUBLE DIAGNOSES FOR SYMPTOMS
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TROUBLE DIAGNOSES FOR SYMPTOMSPFP:99999
Load Leveling Rear Air Suspension System Does Not OperateEES0011D
1. CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to RSU-14, "
SELF-DIAGNOSIS" .
2. CHECK FUSES

Check that the following fuses are not blown.
OK or NG
OK >> GO TO 3.
NG >> If fuse is blown, be sure to eliminate cause of blown fuse before installing new fuse. Refer to PG-
4, "POWER SUPPLY ROUTING CIRCUIT" .
3. CHECK SUSPENSION CONTROL UNIT POWER AND GROUND
1. Turn the ignition switch ON.
2. Check voltage between suspension control unit connector B3
terminal 6 (G/R) and ground and between suspension control
unit connector B3 terminal 7 (W/L) and ground.
3. Turn ignition switch OFF.
4. Check resistance between suspension control unit connector B3
terminal 16 (B) and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair the circuit.
Unit Terminals Signal name Fuse or Fusible Link
Suspension control unit6 Ignition switch ON or START 12 (10A)
7
Battery power29 (10A)
Compressor motor relay 5 g (30A)
Combination meter24 Ignition switch ON or START 14 (10A)
8 Battery power 19 (10A)
Voltage : Approx. 12V
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Continuity should exist.
WEIA0070E

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
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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
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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.
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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
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