height INFINITI QX56 2011 Factory Service Manual

SCS-78
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
C1804 VHCL HEIGHT ADJ UP
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace damaged part.
4.CHECK AIR COMPRESSOR
RELAY OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect air compressor connector.
3. Check continuity between air compressor relay harness connector and air compressor harness connector.
4. Check continuity between air compressor relay harness connector and ground.
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged part.
5.CHECK AIR COMPRESSOR GROUND
Check continuity between air compressor harness connector and ground.
Are the inspection results normal?
YES >> GO TO 6.
NO >> Repair or replace damaged part.
6.CHECK AIR COMPRESSOR RELAY
Check the air compressor relay. Refer to SCS-79, "
Component Inspection (Air Compressor Relay)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace the air compressor relay.
7.CHECK AIR COMPRESSOR
Check the air compressor. Refer to SCS-79, "
Component Inspection (Air Compressor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Replace the air compressor. Refer to SCS-95, "
Removal and Installation".
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> 1. Perform “STANDARD VEHICLE HEIGHT SETTING”. Refer to SCS-67, "Work Procedure".
2. If DTC is detected, replace the air levelizer control module. Refer to SCS-94, "
Removal and
Installation".
Air compressor relay
—Voltage
Connector Terminal
E116 5 Ground Battery voltage
Air compressor rela y Air compressor
Continuity
Connector Terminal Connector Terminal
E116 3 C12 1 Existed
Air compressor relay —Continuity
Connector Terminal
E116 3 Ground Not existed
Air compressor —Continuity
Connector Terminal
C12 2 Ground Existed
Revision: 2010 May2011 QX56

C1804 VHCL HEIGHT ADJ UPSCS-79
< DTC/CIRCUIT DIAGNOSIS > [AIR LEVELIZER CONTROL SYSTEM]
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NO >> Repair or replace damaged part.
Component Inspection (A ir Compressor Relay)INFOID:0000000006256072
1.CHECK AIR COMPRESSOR RELAY
1. Remove the air compressor relay. Refer to SCS-50, "
Component Parts Location".
2. Apply 12 V direct current between air compressor relay terminals 1 and 2. CAUTION:
 Never make the terminals short.
 Connect the fuse between the term inals when applying the voltage.
3. Check continuity between air compressor relay terminals 3 and 5.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace the air compressor relay. Refer to SCS-50, "
Component Parts Location".
Component Inspection (Air Compressor)INFOID:0000000006256073
CAUTION:
Keep the inside of air compressor free of dust.
1.CHECK AIR COMPRESSOR
1. Remove the air compressor. Refer to SCS-95, "
Removal and Installation".
2. Apply 12 V direct current between air compressor terminals 1 and 2. CAUTION:
 Never make the terminals short.
 Connect the fuse between the term inals when applying the voltage.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace the air compressor. Refer to SCS-95, "
Removal and Installation".
(+) (fuse) (−)
Condition Continuity
Air compressor relay
Te r m i n a l
2 1 Apply 12 V direct current between terminals 2 and 1. Existed
— — Does not apply 12 V direct current between terminals 2 and 1. Not existed
(+) (fuse) ( −)
Condition Status
Air compressor
Te r m i n a l
1 2 Apply 12 V direct current between terminals 1 and 2. Air flows from air exhaust holes.
Revision: 2010 May2011 QX56

SCS-80
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
C1805 VHCL HE
IGHT ADJ DOWN
C1805 VHCL HEIGHT ADJ DOWN
DTC LogicINFOID:0000000006256074
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. Start the engine and wait 150 seconds or more.
2. Perform “Self Diagnostic Result” in “E-SUS”.
Is
“C1805” detected ?
YES >> Go to SCS-80, "DiagnosisProcedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006256075
1.CHECK APPEARANCE
Visually check for malfunction of suspension components, crush of air tube, installation malfunction, or defor-
mation of vehicle height sensor.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repaire or replace damaged parts.
2.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Perform “STANDARD VEHICLE HEIGHT SETTING”. Refer to SCS-67, "Work Procedure".
NO >> Repair or replace damaged part.
DTC Display item Malfunction detected condition Possible cause
C1805 VHCL HEIGHT ADJ DOWN The vehicle height is 15 mm (0.59 in) or more raise than
the reference height despite the output of exhaust sole-
noid ON signal continuously for 120 seconds by the air
levelizer control module.  Harness or connector
 Vehicle height sensor
Air compressor
(exhaust sole-
noid)
Air tube
 Rear suspension component
parts
Revision: 2010 May2011 QX56

C1806 VHCL HEIGHT SEN FIXSCS-81
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C1806 VHCL HEIGHT SEN FIX
DTC LogicINFOID:0000000006256076
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 VEHICLE HEIGHT SENSOR FIXATION
With CONSULT-III
1. Start the engine.
2. Select “VHCL HEIGHT SEN” in “Data Monitor” in “E-SUS”.
3. Drive vehicle and maintain the following conditions for 5 minutes or more.
Does the value of
“VHCL HEIGHT SEN” change?
YES >> INSPECTION END
NO >> Go to SCS-81, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006256077
1.CHECK APPEARANCE
Visually check for installation malfunction, or deformation of vehicle height sensor.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repaire or replace damaged parts.
2.CHECK VEHICLE HEIGHT SENSOR
Check the vehicle height sensor. Refer to SCS-70, "
Component Inspection".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace the vehicle height sensor. Refer to SCS-98, "
Removal and Installation".
DTC Display item Malfunction detected condition Possible cause
C1806 VHCL HEIGHT SEN FIX The signal voltage of the vehicle height sensor does
not change for cumulated time of 100 hours under the
condition that the air levelizer control module outputs
sensor voltage (4.5 – 5.5 V) with vehicle speeds 2
km/h (2 MPH) or more.  Harness or connector
 Vehicle height sensor
Vehicle speed : 5 km/h (3 MPH) or more
Revision: 2010 May2011 QX56

SCS-82
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
C1807 VHCL HEIGHT SEN VOLT
C1807 VHCL HEIGHT SEN VOLT
DTC LogicINFOID:0000000006256078
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 20 seconds or more.
2. Perform “Self Diagnostic Results” in “E-SUS”.
Is
“C1807” detected ?
YES >> Go to SCS-82, "DiagnosisProcedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006256079
1.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 the vehicle height sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK POWER SUPPLY CIRCUIT (PART 2)
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.
DTC Display item Malfunction detected condition Possible cause
C1807 VHCL HEIGHT SEN VOLT The sensor power supply is more than 5.5 V or less
than 4.5 V continuously for 20 seconds when the ig-
nition switch is ON.
 Harness or connector
 Vehicle height sensor
 Air levelizer control module
Sensor power supply is 0.5 V or more continuously for
1 second during 2 seconds after turning ON the igni-
tion switch.
Vehicle height sensor
—Voltage
Connector Terminal
C13 1 Ground 4.5 – 5.5 V
Air levelizer control module Vehicle height sensor Continuity
Connector Terminal Connector Terminal
B84 13 C13 1 Existed
Revision: 2010 May2011 QX56

C1807 VHCL HEIGHT SEN VOLTSCS-83
< DTC/CIRCUIT DIAGNOSIS > [AIR LEVELIZER CONTROL SYSTEM]
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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 t he air levelizer control module. Refer to SCS-94, "
Removal
and Installation".
NO >> Repair or replace damaged parts.
3.CHECK HARNESS BETWEEN AIR LE VELIZER CONTROL MODULE AND VEHICLE HEIGHT SENSOR
1. Turn ignition switch OFF.
2. Disconnect air levelizer control module connector.
3. Check continuity between air levelizer control module 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 4.
NO >> Repair or replace damaged parts.
4.CHECK VEHICLE HEIGHT SENSOR
Check the vehicle height sensor. Refer to SCS-70, "
Component Inspection".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace the vehicle height sensor. Refer to SCS-98, "
Removal and Installation".
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

SCS-84
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
C1808 AIR SUS COMPRS FNCTN
C1808 AIR SUS COMPRS FNCTN
DTC LogicINFOID:0000000006256080
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. Set vehicle in the unloaded vehicle status.
2. Start the engine and wait 5 minutes or more.
3. Perform “Self Diagnostic Result” in “E-SUS”.
Is
“C1808” detected ?
YES >> Go to SCS-84, "DiagnosisProcedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006256081
1.CHECK APPEARANCE
Visually check for malfunction of suspension component s, damage of air chamber of rear shock absorber,
installation malfunction, or deformation of vehicle height sensor.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repaire or replace damaged parts.
2.CHECK AIR LEAK
Apply soapy water to air tube, connecting portions between air tube and each component, and air chamber of
rear shock absorber. Check for air leakage.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repaire or replace damaged parts.
3.CHECK AIR COMPRESSOR RELAY POWER SUPPLY
1. Turn ignition switch OFF.
2. Check 30A fuse (#I).
3. Disconnect air compressor relay connector.
4. Check voltage between air compressor relay harness connector and ground.
DTC Display item Malfunction detected condition Possible cause
C1808 AIR SUS COMPRS FNCTN The cumulative operating time of the air compressor
reaches 180 seconds or more.
NOTE:
Cumulative time is cleared under the following condi-
tions:
 Ignition switch: OFF
 Exhaust conditions: satisfied [Vehicle height re-
mains 15 mm (0.59 in) or more higher than the ref-
erence height for 30 seconds.]  Harness or connector
 Vehicle height sensor
 Air compressor (exhaust sole-
noid)
 Air compressor relay
 Overloaded
 Rear shock absorber (air cham- ber)
 Rear suspension component parts
 Air tube
Revision: 2010 May2011 QX56

C1808 AIR SUS COMPRS FNCTNSCS-85
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Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace damaged part.
4.CHECK AIR COMPRESSOR RELAY OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect air compressor connector.
3. Check continuity between air compressor rela y harness connector and air compressor harness connector.
4. Check continuity between air compressor relay harness connector and ground.
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged part.
5.CHECK AIR COMPRESSOR GROUND
Check continuity between air compressor harness connector and ground.
Are the inspection results normal?
YES >> GO TO 6.
NO >> Repair or replace damaged part.
6.CHECK AIR COMPRESSOR RELAY
Check the air compressor relay. Refer to SCS-79, "
Component Inspection (Air Compressor Relay)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace the air compressor relay.
7.CHECK AIR COMPRESSOR
Check the air compressor. Refer to SCS-79, "
Component Inspection (Air Compressor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Replace the air compressor. Refer to SCS-95, "
Removal and Installation".
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> 1. Perform “STANDARD VEHICL E HEIGHT SETTING”. Refer to SCS-67, "Work Procedure".
2. If DTC is detected, replace the air levelizer control module. Refer to SCS-94, "
Removal and
Installation".
Air compressor relay
—Voltage
Connector Terminal
E116 5 Ground Battery voltage
Air compressor relay Air compressor Continuity
Connector Terminal Connector Terminal
E116 3 C12 1 Existed
Air compressor relay —Continuity
Connector Terminal
E116 3 Ground Not existed
Air compressor —Continuity
Connector Terminal
C12 2 Ground Existed
Revision: 2010 May2011 QX56

SCS-90
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
CK SUSP INDICATOR LAMP CIRCUIT
CK SUSP INDICATOR LAMP CIRCUIT
DescriptionINFOID:0000000006256089
Air levelizer control module transmits CK SUSP indicator lamp signal to combination meter via CAN communi-
cation, when setting of standard vehicle height is incomplete. Based on the signal, combination meter turns
CK SUSP indicator lamp ON.
Component Function CheckINFOID:0000000006256090
1.CHECK CK SUSP INDICATOR LAMP OPERATION
CONSULT-III
1. Turn ignition switch ON.
2. Select “WARNING LAMP” in “Active Test” in “E-SUS”.
3. While operating test item, check that the CK SUSP indicator lamp activates.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Refer to SCS-90, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006256091
1.PERFORM SELF-DIAGNOSIS
CONSULT-III
1. Turn ignition switch ON.
2. Select “Self Diagnostic Result” in “E-SUS”.
Are any DTC detected?
YES >> Refer to SCS-59, "DTC Index".
NO >> GO TO 2.
2.CHECK COMBINATION METER
Check combination meter. Refer to MWI-29, "
On Board Diagnosis Function".
Is the inspection result normal?
YES >> Replace the air levelizer control module. Refer to SCS-94, "Removal and Installation".
NO >> Repair or replace the combination meter. Refer to MWI-85, "
Removal and Installation".
ON : CK SUSP indicator lamp turns ON
OFF : CK SUSP indicator lamp turns OFF
Revision: 2010 May2011 QX56

VEHICLE HEIGHT CANNOT BE RAISEDSCS-91
< SYMPTOM DIAGNOSIS > [AIR LEVELIZER CONTROL SYSTEM]
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SYMPTOM DIAGNOSIS
VEHICLE HEIGHT CANNOT BE RAISED
DescriptionINFOID:0000000006256092
Vehicle height remains in low status.
Diagnosis ProcedureINFOID:0000000006256093
1.CHECK APPEARANCE
Visually check for fuse, malfunction of suspension components, installation malfunction, or deformation of
vehicle height sensor.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repaire or replace damaged parts.
2.PERFORM SELF-DIAGNOSIS
1. Turn ignition switch ON.
2. Select “Self Diagnostic Result” in “E-SUS”.
Are any DTC detected?
YES >> Refer to SCS-59, "DTC Index".
NO >> GO TO 3.
3.PERFORM STANDARD VEHICLE HEIGHT SETTING
Refer to SCS-67, "
Work Procedure".
Is the symptom improved?
YES >> INSPECTION END
NO >> Replace the air levelizer control module. Refer to SCS-94, "
Removal and Installation".
Revision: 2010 May2011 QX56