ground INFINITI QX56 2011 Factory Service Manual

SBC-60
< SYMPTOM DIAGNOSIS >
PRE-CRASH SEAT BELT DOSE NOT OPERATE
SYMPTOM DIAGNOSIS
PRE-CRASH SEAT BELT DOSE NOT OPERATE
Diagnosis ProcedureINFOID:0000000006237940
1.CHECK POWER SUPPLY AND GROUND CIRCUIT
Check power supply and ground circuit. Refer to SBC-52, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace the malfunctioning parts.
2.CHECK SEAT BELT ASSEMBLY (DRIVER SIDE)
Check seat belt assembly (driver side). Refer to SBC-53, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace the malfunctioning parts.
3.CHECK SEAT BELT ASSEMBLY (PASSENGER SIDE)
Check seat belt assembly (passenger side). Refer to SBC-55, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace the malfunctioning parts.
4.CONFIRM THE OPERATION
Confirm the operation again.
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> GO TO 1.
Revision: 2010 May2011 QX56

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Description ..........................................................
....
87
DTC Logic ...............................................................87
Diagnosis Procedure ...............................................87
U1010 CONTROL UNIT (CAN) ..........................88
Description .......................................................... ....88
DTC Logic ...............................................................88
Diagnosis Procedure ...............................................88
POWER SUPPLY AND GROUND CIRCUIT ......89
Diagnosis Procedure .......................................... ....89
CK SUSP INDICATOR LAMP CIRCUIT ............90
Description .......................................................... ....90
Component Function Check ....................................90
Diagnosis Procedure ...............................................90
SYMPTOM DIAGNOSIS ..............................91
VEHICLE HEIGHT CANNOT BE RAISED ..... ....91
Description .......................................................... ....91
Diagnosis Procedure ...............................................91
VEHICLE HEIGHT CANNOT BE LOWERED ....92
Description ..............................................................92
Diagnosis Procedure ........................................... ....92
CK SUSP INDICATOR LAMP DOES NOT
TURN OFF ........................................ .................
93
Description ........................................................... ....93
Diagnosis Procedure ...............................................93
REMOVAL AND INSTALLATION ...............94
AIR LEVELIZER CONTROL MODULE ............94
Exploded View ..................................................... ....94
Removal and Installation .........................................94
Adjustment ...............................................................94
AIR COMPRESSOR/AIR TUBE ........................95
Exploded View .........................................................95
Removal and Installation .........................................95
Inspection ................................................................97
VEHICLE HEIGHT SENSOR ............................98
Exploded View .........................................................98
Removal and Installation .........................................98
Adjustment ...............................................................99
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

CHECK ORIFICE FOR CLOGGINGSCS-27
< BASIC INSPECTION > [HBMC]
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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

SCS-58
< ECU DIAGNOSIS INFORMATION >[AIR LEVELIZER CONTROL SYSTEM]
AIR LEVELIZER CONTROL MODULE
ECU DIAGNOSIS INFORMATION
AIR LEVELIZER CONTROL MODULE
Reference ValueINFOID:0000000006256053
VALUES ON DIAGNOSIS TOOL
TERMINAL LAYOUT
PHYSICAL VALUES
Item name Condition Value/Status (Approx.)
IGN VOLT Ignition switch ON 10 – 16 V
VHCL HT INTLZ STA Completion of the standard vehicle height setting CMPLT
Other than the above INCMP
VHCL HT INIT SLCT Completion of the standard vehicle height setting 1
Other than the above 0
VHCL HEIGHT SEN Lift up the vehicle 2.8 – 3.8 V
VHCL HT CNVSN VL Lift down the vehicle −15 – 15 mm
VHCL HGT FIX TIME Lift up the vehicle 0 h
VHCL HGT INIT VAL Completion of the standard vehicle height setting 2.800 – 3.800 V
Other than the above 0 V
COMPRESSOR When the air compressor is operating On
Other than the above Off
EXH SOLENOID When exhaust solenoid is operating On
Other than the above Off
ENG SPEED SIG Engine running RUN
Other than the above STOP
WARNING LAMP When CK SUSP indicator lamp is ON On
Other than the above Off
JSDIA0057ZZ
Terminal
(Wire color) Description
ConditionReference value
(Approx.)
+ − Signal name Input/
Output
2
(B) Ground GND — Always Less than 1
Ω
3
(V) Ground Air compressor relay Output IGN ON Air compressor: ON 9 – 16 V
Air compressor: OFF Less than 2 V
4
(L/W) Ground Vehicle height sensor
(GND) — Always Less than 1
Ω
Revision: 2010 May2011 QX56

AIR LEVELIZER CONTROL MODULESCS-59
< ECU DIAGNOSIS INFORMATION > [AIR LEVELIZER CONTROL SYSTEM]
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Fail-safeINFOID:0000000006256054
If malfunction is detected, control stops.
The system may enter fail-safe mode under certain condi tions (for example, over-laden conditions) when elec-
tronic circuit is normal.
In this case, always check that the system re turns to normal by starting engine after unloading load.
DTC Inspection Priority ChartINFOID:0000000006256055
If some DTCs are displayed at the same time, per form inspections one by one based on the following priority
chart.
DTC IndexINFOID:0000000006256056
5
(W) Ground Vehicle height sensor
(SIGNAL) InputIGN ON 0.2 – 4.6 V
IGN OFF 0 V
7
(P) 16
(L) CAN-L
Input/
Output — 54 – 69
Ω
9
(P/L) Ground Air levelizer co
ntrol module
power supply InputIGN ON 10 – 16 V
IGN OFF 0 V
11
(V/W) Ground Exhaust solenoid Output IGN ON Exhaust solenoid: ON 9 – 16 V
Exhaust solenoid: OFF Less than 2 V
13
(R) Ground Vehicle height sensor
(Power supply)
OutputIGN ON 4.5 – 5.5 V
IGN OFF 0 V
16
(L) 7
(P) CAN-H Input/
Output — 54 – 69
Ω
Te r m i n a l
(Wire color) Description
ConditionReference value
(Approx.)
+ − Signal name Input/
Output
Priority Detected items (DTC)
1  U1000 CAN COMM CIRCUIT
 U1010 CONTROL UNIT (CAN)
2  C1801 VHCL HEIGHT SENSOR
 C1802 AIR SUS COMPRS RELAY
 C1803 AIR SUS EXH SOL
 C1806 VHCL HEIGHT SEN FIX
 C1807 VHCL HEIGHT SEN VOLT
3  C1804 VHCL HEIGHT ADJ UP
 C1805 VHCL HEIGHT ADJ DOWN
 C1808 AIR SUS COMPRS FNCTN
DTC CONSULT-III display Reference page
C1801 VHCL HEIGHT SENSOR SCS-69
C1802 AIR SUS COMPRS RELAYSCS-72
C1803 AIR SUS EXH SOLSCS-74
C1804 VHCL HEIGHT ADJ UPSCS-77
C1805 VHCL HEIGHT ADJ DOWNSCS-80
C1806 VHCL HEIGHT SEN FIXSCS-81
C1807 VHCL HEIGHT SEN VOLTSCS-82
C1808 AIR SUS COMPRS FNCTNSCS-84
Revision: 2010 May2011 QX56

STANDARD VEHICLE HEIGHT SETTINGSCS-67
< BASIC INSPECTION > [AIR LEVELIZER CONTROL SYSTEM]
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STANDARD VEHICL E HEIGHT SETTING
DescriptionINFOID:0000000006256060
Air levelizer control module enables precise control, by acquiring memorized standard vehicle height and sig-
nal (vehicle height) from vehicle height sensor. For this reason, always set standard vehicle height after per-
forming the following operations.
 Removal and installation or replacement of vehicle height sensor
 Replacement of air levelizer control module
Work ProcedureINFOID:0000000006256061
1.CLEAR STANDARD VEHICLE HEIGHT
With CONSULT-III
1. Lift up the vehicle. CAUTION:
Check that tires never contact the ground.
2. Start the engine.
3. Select “COMPRESSOR” in “Active Test” in “E-SUS”.
4. Touch “ON” and wait 60 seconds or more.
5. Touch “OFF”.
6. Select “CLEAR HEIGHT INI” in “Work Support” in “E-SUS”.
7. Touch “Start”.
8. Touch “Clear”. NOTE:
CONSULT-III continues indicating "EXECUTING". The completion of the standard vehicle height erasing
can be checked by the CK SUSP indicator lamp ON condition.
Does CK SUSP indicator lamp turn ON?
YES >> GO TO 2.
NO >> Perform step 1 again.
2.ADJUST STANDARD VEHICLE HEIGHT
With CONSULT-III
1. Select “ADJUST HEIGHT INI” in “Work Support” in “E-SUS”.
2. Touch “Start”.
3. Touch “Initial 1”. NOTE:
CONSULT-III continues indicating "EXECUTING". T he completion of the standard vehicle height adjust-
ment can be checked by the CK SUSP indicator lamp OFF condition.
Does CK SUSP indicator lamp turn OFF?
YES >> GO TO 3.
NO >> Perform step 1 again.
3. ADJUST VEHICLE HEIGHT
With CONSULT-III
1. Lift down the vehicle. CAUTION:
Check that the lift is fully lowered.
2. Select “STANDARD HEIGHT LEVEL” in “Work Support” in “E-SUS”.
3. Touch “Start”.
4. Touch “Revert” and wait 120 seconds or more.
5. Although CONSULT-III continues indicating "EXECUTIN G", select “VHCL HGT CNVSN VL” in “Data Mon-
itor” in “E-SUS”.
Is value within
−15 – 15 mm?
YES >> GO TO 4.
NO >> Perform step 1 again.
4.CHECK DTC
With CONSULT-III
Revision: 2010 May2011 QX56

C1801 VHCL HEIGHT SENSORSCS-69
< DTC/CIRCUIT DIAGNOSIS > [AIR LEVELIZER CONTROL SYSTEM]
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DTC/CIRCUIT DIAGNOSIS
C1801 VHCL HEIGHT SENSOR
DTC LogicINFOID:0000000006256062
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” has been previous ly conducted, always turn ignition switch OFF
andwait at least 10 seconds before conducting the next test.
>> GO TO 2.
2.CHECK DTC DETECTION
With CONSULT-III
1. Turn ignition switch ON and wait 60 seconds or more.
2. Perform “Self Diagnostic Results” in “E-SUS”.
Is
“C1801” detected ?
YES >> Go to SCS-69, "DiagnosisProcedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006256063
1.CHECK APPEARANCE
Visually check for malfunction of suspension components, installing malfunction, or deformation of vehicle
height sensor.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repaire or replace damaged parts.
2.CHECK POWER SUPPLY CIRCUIT (PART 1)
1. Disconnect vehicle height sensor connector.
2. Turn ignition switch ON. CAUTION:
Never start the engine.
3. Check voltage between vehicle height sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK POWER SUPPLY CIRCUIT (PART 2)
1. Turn ignition switch OFF.
2. Disconnect air levelizer control module connector.
DTC Display itemI Malfunction detected condition Possible cause
C1801 VHCL HEIGHT SENSOR Signal voltage of the vehicle height sensor remains 0.2
V or less or 4.6 V or more continuously for 60 seconds
during sensor voltage (4.5 – 5.5 V) output by the air lev-
elizer control module.  Harness or connectors
(Sensor circuit is open.)
 Vehicle height sensor
 Air levelizer control module
 Rear suspension component parts
Vehicle height sensor —Voltage
Connector Terminal
C13 1 Ground 4.5 – 5.5 V
Revision: 2010 May2011 QX56

SCS-70
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
C1801 VHCL HEIGHT SENSOR
3. Check continuity between air levelizer control m
odule harness connector and vehicle height sensor har-
ness connector.
4. Check continuity between air levelizer control module harness connector and ground.
Is the inspection result normal?
YES >> 1. Check intermittent incident. Refer to GI-40, "Intermittent Incident".
2. If inspection result is OK, replace the air levelizer control module. Refer to SCS-94, "
Removal
and Installation".
NO >> Repair or replace damaged parts.
4.CHECK HARNESS BETWEEN AIR LEVELIZER CO NTROL MODULE AND VEHICLE HEIGHT SENSOR
1. Turn ignition switch OFF.
2. Disconnect air levelizer control module connector.
3. Check continuity between air levelizer control m odule harness connector and vehicle height sensor har-
ness connector.
4. Check continuity between air levelizer control module harness connector and ground.
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK VEHICLE HEIGHT SENSOR
Check the vehicle height sensor. Refer to SCS-70, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace the vehicle height sensor. Refer to SCS-98, "
Removal and Installation".
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Replace the air levelizer control module. Refer to SCS-94, "Removal and Installation".
NO >> Repair or replace damaged parts.
Component InspectionINFOID:0000000006256064
1.CHECK VEHICLE HEIGHT SENSOR
Air levelizer control module Vehicle height sensor Continuity
Connector Terminal Connector Terminal
B84 13 C13 1 Existed
Air levelizer control module —Continuity
Connector Terminal
B84 13 Ground Not existed
Air levelizer control module Vehicle height sensor Continuity
Connector Terminal Connector Terminal
B84 5
C13 2
Existed
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Air levelizer control module —Continuity
Connector Terminal
B84 5
Ground Not existed
4
Revision: 2010 May2011 QX56