2011 INFINITI QX56 ECU

CHECK SYSTEM PRESSURESCS-15
< BASIC INSPECTION > [HBMC]
C
D
F
G H
I
J
K L
M A
B
SCS
N
O P
BASIC INSPECTION
CHECK SYSTEM PRESSURE
Work ProcedureINFOID:0000000006256009
CAUTION:
 Clean surrounding areas of oil inj ection jack using steam before starting operation, since there may
be mud on it.
 Clean oil pressure gauge (special service tool: KV40108000) jack with steam before use.
1. Lift up the vehicle.
2. Remove protector of PPMU.
3. Remove cap of oil injection jack.
4. Install an oil pressure gauge (SST: KV40108000) (A) to oil injec- tion jack.
CAUTION:
 Jack must be securely inserted until a click sound can be
heard.
 Pressure reducing valve (B) of the oil pressure gauge
must be closed.
5. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations.
CAUTION:
Never loosen the needle valve more than required.
6. Refer to the figure and check the specified pressure.
7. Tighten needle valves A, C, and E of PPMU to the specified torque.
JSEIA0186ZZ
JSEIA0187ZZ
Tightening torque : 8.3 N·m (0.85 kg-m, 73 in-lb)
JSEIA0222GB
Revision: 2010 May2011 QX56

PRESSURE REDUCING METHODSCS-17
< BASIC INSPECTION > [HBMC]
C
D
F
G H
I
J
K L
M A
B
SCS
N
O P
PRESSURE REDUCING METHOD
Work ProcedureINFOID:0000000006256010
CAUTION:
 Clean surrounding areas of oil inj ection jack using steam before starting operation, since there may
be mud on it.
 Clean oil pressure gauge (special service tool: KV40108000) jack with steam before use.
1. Lift up the vehicle.
2. Remove protector of PPMU.
3. Remove cap of oil injection jack.
4. Install an oil pressure gauge (SST: KV40108000) (A) to oil injec- tion jack.
CAUTION:
 Jack must be securely inserted until a click sound can beheard.
 Pressure reducing valve (B) of the oil pressure gauge
must be closed.
5. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations.
CAUTION:
Never loosen the needle valve more than required.
6. Loosen pressure reducing valve (A) of oil pressure gauge and then lower pressure.
CAUTION:
Be careful since oil drains sw iftly from oil drain hole (B).
7. Check that reading of oil pressure gauge is 0 MPa.
8. Tighten needle valves A, C, and E of PPMU to the specified torque.
JSEIA0186ZZ
JSEIA0187ZZ
Tightening torque : 8.3 N·m (0.85 kg-m, 73 in-lb)
JSEIA0188ZZ
Revision: 2010 May2011 QX56

SCS-18
< BASIC INSPECTION >[HBMC]
AIR BLEEDING METHOD
AIR BLEEDING METHOD
Work ProcedureINFOID:0000000006256011
WARNING:
 Always check the piping for loose co
nnections, damage, or twists before starting operation, since
pressure in hydraulic circuit b ecomes high during operation.
 When repairing or replacing a malfunctioning pa rt, always release pressure from hydraulic circuit,
since dangerous conditions may be created when oil leakage occurs during air bleeding operation.
CAUTION:
 Clean surrounding areas of oil injection jack and air bleeder using steam before starting operation,
since there may be mud on it.
 Clean suspension oil pump (special servi ce tool: KV40107700) jack with steam before use.
 Check system pressure again 1 day or more after bleeding operation is complete, since system pres-
sure may decrease when air bleeding is insufficient.
1. Lift up the vehicle.
2. Remove protector of PPMU.
3. Remove cap of oil injection jack.
4. Install hose (A) of a suspension oil pump (SST: KV40107700) to oil injection jack.
CAUTION:
Jack must be securely inserted until a click sound can be
heard.
5. Loosen pressure reducing valve (A) of hose portion of suspen- sion oil pump.
6. Set knob (A) of suspension oil pump to the direction as shown in the figure.
7. Close pressure reducing valve of hose portion of suspension oil pump while sending oil by applying pressure using suspension
oil pump. (Air bleeding in hose is complete.)
JSEIA0189ZZ
JSEIA0190ZZ
JSEIA0191ZZ
Revision: 2010 May2011 QX56

SCS-20
< BASIC INSPECTION >[HBMC]
CHECK INTERNAL LEAKAGE
CHECK INTERNAL LEAKAGE
Work ProcedureINFOID:0000000006256012
CAUTION:
 Clean surrounding areas of
oil injection jack using steam before starting operation, since there may
be mud on it.
 Clean oil pressure gauge (special service tool: KV40108000) jack with steam before use.
1. Remove protector of PPMU.
2. Remove cap of oil injection jack.
3. Install an oil pressure gauge (SST: KV40108000) (A) to oil injec- tion jack.
CAUTION:
 Jack must be securely inserted until a click sound can beheard.
 Pressure reducing valve (B) of the oil pressure gauge
must be closed.
4. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations. CAUTION:
Never loosen the needle valve more than required.
5. Lift up the vehicle. CAUTION:
Check that tires never contact the ground.
6. Tighten needle valves C and E of PPMU.
7. Loosen lock nut of needle valve D of PPMU and then tighten needle valve D.
8. Lift down the vehicle. CAUTION:
Check that the lift is fully lowered.
9. Write down a value of the oil pressure gauge after 5 minutes.
10. Tighten needle valve A of PPMU.
11. Loosen lock nut of needle valve B of PPMU and then tighten needle valve B.
12. Loosen needle valve C of PPMU by approximately 2 rotations. CAUTION:
Never loosen the needle valve more than required.
13. Read a value of oil pressure gauge.
14. Compare difference of reading with pressure reading in step 9.
15. Tighten needle valves A, C, and E of PPMU to the specified torque.
16. Loosen needle valves B and D of PPMU by approximatel y 2 rotations and then tighten lock nut to the
specified torque.
CAUTION:
Never loosen the needle valve more than required.
JSEIA0186ZZ
Pressure difference
0.1 MPa or more : Normal
0.1 MPa or less : Malfunction
: 8.3 N·m (0.85 kg-m, 73 in-lb)
JSEIA0187ZZ
Revision: 2010 May2011 QX56

SCS-22
< BASIC INSPECTION >[HBMC]
CHECK FOR MALFUNCTION
CHECK FOR MALFUNCTION
Work ProcedureINFOID:0000000006256013
CAUTION:
 Clean surrounding areas of
oil injection jack using steam before starting operation, since there may
be mud on it.
 Clean oil pressure gauge (special service tool: KV40108000) jack with steam before use.
1. Remove protector of PPMU.
2. Remove cap of oil injection jack.
3. Install an oil pressure gauge (SST: KV40108000) (A) to oil injec- tion jack.
CAUTION:
 Jack must be securely inserted until a click sound can beheard.
 Pressure reducing valve (B) of the oil pressure gauge
must be closed.
4. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations.
CAUTION:
Never loosen the needle valve more than required.
5. Lift up the vehicle. CAUTION:
Check that tires never contact the ground.
6. Tighten needle valves A and C of PPMU.
7. Loosen lock nuts of needle valves B and D of PPMU and then tighten needle valves B and D.
8. Write down a value of the oil pressure gauge.
9. Lift down the vehicle. CAUTION:
Check that the lift is fully lowered.
10. Read a value of oil pressure gauge.
11. Compare difference of reading with pressure reading in step 8.
12. Tighten needle valves A, C, and E of PPMU to the specified torque.
13. Loosen needle valves B and D of PPMU by approximatel y 2 rotations and then tighten lock nut to the
specified torque.
CAUTION:
Never loosen the needle valve more than required.
JSEIA0186ZZ
Pressure change
Pressure increases : PPMU malfunction
Pressure does not change : Shock absorber malfunction
Tightening torque : 8.3 N· m (0.85 kg-m, 73 in-lb)
Tightening torque : 20 N·m (2.0 kg-m, 15 ft-lb)
JSEIA0187ZZ
Revision: 2010 May2011 QX56

SCS-24
< BASIC INSPECTION >[HBMC]
CHECK SHOCK ABSORBER FOR MALFUNCTION
CHECK SHOCK ABSORBER
FOR MALFUNCTION
Work ProcedureINFOID:0000000006256014
CAUTION:
 Clean surrounding areas of oil injection jack using steam before starting operation, since there may
be mud on it.
 Clean suspension oil pump (special servi ce tool: KV40107700) jack with steam before use.
 Clean leak check plug (special service to ol: KV40108400) jack with steam before use.
 Check each shock absorber, one by one, in accordance with the following procedures.
1. Lift up the vehicle.
2. Remove protector of PPMU.
3. Remove cap of oil injection jack.
4. Install hose (A) of a suspension oil pump (SST: KV40107700) to oil injection jack.
CAUTION:
 Jack must be securely inserted until a click sound can be
heard.
 Pressure reducing valve (B) of the suspension oil pump
must be closed.
5. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations.
CAUTION:
Never loosen the needle valve more than required.
6. Set knob (A) of suspension oil pump to the direction as shown in the figure and check that reading of pressure gauge is 0 MPa.
7. Tighten needle valves A, C, and E of PPMU.
8. Disconnect upper side pipe or lower side pipe of each shock absorber.  For front shock absorber
JSEIA0244ZZ
JSEIA0187ZZ
JSEIA0193ZZ
Revision: 2010 May2011 QX56

CHECK ORIFICE FOR CLOGGINGSCS-27
< BASIC INSPECTION > [HBMC]
C
D
F
G H
I
J
K L
M A
B
SCS
N
O P
CHECK ORIFICE FOR CLOGGING
Work ProcedureINFOID:0000000006256015
CAUTION:
 Clean surrounding areas of oil inj ection jack using steam before starting operation, since there may
be mud on it.
 Clean oil pressure gauge (special service tool: KV40108000) jack with steam before use.
1. Remove protector of PPMU.
2. Remove cap of oil injection jack.
3. Install an oil pressure gauge (SST: KV40108000) (A) to oil injec- tion jack.
CAUTION:
 Jack must be securely inserted until a click sound can beheard.
 Pressure reducing valve (B) of the oil pressure gauge
must be closed.
4. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations.
CAUTION:
Never loosen the needle valve more than required.
5. Lift up the vehicle. CAUTION:
Check that tires never contact the ground.
6. Tighten needle valves A, C, and E of PPMU.
7. Lift down the vehicle. CAUTION:
Check that the lift is fully lowered.
8. Loosen pressure reducing valve (A) of oil pressure gauge and then lower pressure.
CAUTION:
Be careful since oil drains sw iftly from oil drain hole (B).
9. Check that reading of oil pressure gauge is 0 MPa. Close pres- sure reducing valve.
10. Loosen needle valve E of PPMU by approximately 2 rotations. CAUTION:
Never loosen the needle valve more than required.
11. Write down a value of the oil pressure gauge.
12. Tighten needle valve E of PPMU.
13. Loosen pressure reducing valve of oil pressure gauge and then lower pressure. CAUTION:
Be careful since oil drains swiftly from oil drain hole.
14. Check that reading of oil pressure gauge is 0 MPa. Close pressure reducing valve.
15. Loosen needle valve A of PPMU by approximately 2 rotations. CAUTION:
Never loosen the needle valve more than required.
16. Read a value of the oil pressure gauge after 5 minutes.
17. Compare difference of reading with pressure reading in step 11.
JSEIA0186ZZ
JSEIA0187ZZ
JSEIA0188ZZ
Revision: 2010 May2011 QX56

DIFFERENCE IN APPEARANCESCS-29
< SYMPTOM DIAGNOSIS > [HBMC]
C
D
F
G H
I
J
K L
M A
B
SCS
N
O P
SYMPTOM DIAGNOSIS
DIFFERENCE IN APPEARANCE
DescriptionINFOID:0000000006256016
While the vehicle is stopped, the difference of vehicle height of right side and left side (between wheel center
and wheel arch) is 25 mm (0.98 in) or more.
Inspection ProcedureINFOID:0000000006256017
1.CHECK APPEARANCE
1. Visually check that the exterior parts (e.g. suspension spring) have no malfunctions.
2. Visually check tube and pipe for crush or oil leakage.
Is the check result normal?
YES >> GO TO 2.
NO >> Repair or replace damaged parts.
2.CHECK CLOGGING OF ORIFICE IN PPMU
1. Install an oil pressure gauge (SST: KV40108000) (A) to oil injec- tion jack.
CAUTION:
 Clean surrounding areas of oi l injection jack using steam
before starting oper ation, since there may be mud on it.
 Clean oil pressure gauge (special service tool:
KV40108000) jack with steam before use.
 Jack must be securely inserted until a click sound can be heard.
 Pressure reducing valve (B) of the oil pressure gauge
must be closed.
2. Loosen needle valves A and C of PPMU by approximately 2 rotations for check changes in vehicle height.
CAUTION:
Never loosen the needle valve more than required.
3. Tighten needle valve A and C of PPMU to the specified torque after the inspection.
Does the vehicle height change 10 mm (0.39 in) or more?
YES >> For detailed inspection of clogging of orifice in PPMU, refer to SCS-27, "
Work Procedure".
NO >> INSPECTION END
JSEIA0186ZZ
Tightening torque : 8.3 N· m (0.85 kg-m, 73 in-lb)
JSEIA0187ZZ
Revision: 2010 May2011 QX56