INFINITI QX56 2011 Factory Service Manual

C1806 VHCL HEIGHT SEN FIXSCS-81
< DTC/CIRCUIT DIAGNOSIS > [AIR LEVELIZER CONTROL SYSTEM]
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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
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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
43
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-86
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
C1808 AIR SUS COMPRS FNCTN
NO >> Repair or replace damaged part.
Revision: 2010 May2011 QX56

U1000 CAN COMM CIRCUITSCS-87
< DTC/CIRCUIT DIAGNOSIS > [AIR LEVELIZER CONTROL SYSTEM]
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U1000 CAN COMM CIRCUIT
DescriptionINFOID:0000000006256082
CAN (Controller Area Network) is a serial communication line for real-time application. It is an on-vehicle mul-
tiplex communication line with high data communica tion speed and excellent malfunction detection ability.
Many electronic control units are equipped onto a vehicl e, and each control unit shares information and links
with other control units during operation (not independently ). In CAN communication, control units are con-
nected with 2 communication lines (CAN-H line, CAN-L li ne) allowing a high rate of information transmission
with less wiring. Each control unit transmits/recei ves data but selectively reads required data only.
DTC LogicINFOID:0000000006256083
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” is previously c onducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.
>> GO TO 2.
2.CHECK DTC DETECTION
With CONSULT-III
1. Start the engine.
2. Run engine for at least 2 cons ecutive seconds at idle speed.
3. Perform “Self Diagnostic Results” in “E-SUS”.
Is
“U1000” detected?
YES >> Go to SCS-87, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006256084
Go to LAN-18, "Trouble Diagnosis Flow Chart".
DTC Display itemI Malfunction detected condition Possible cause
U1000 CAN COMM CIRCUIT Air levelizer control module is not transmitting or re-
ceiving CAN communication signal for 2 seconds or
more.  Harness or connectors
(CAN communication line is open or
shorted.)
 Air levelizer control module
Revision: 2010 May2011 QX56

SCS-88
< DTC/CIRCUIT DIAGNOSIS >[AIR LEVELIZER CONTROL SYSTEM]
U1010 CONTROL UNIT (CAN)
U1010 CONTROL UNIT (CAN)
DescriptionINFOID:0000000006256085
CAN (Controller Area Network) is a serial communication
line for real-time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent malfunction detection ability.
Many electronic control units are equipped onto a vehi cle, and each control unit shares information and links
with other control units during operation (not independently ). In CAN communication, control units are con-
nected with 2 communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission
with less wiring. Each control unit transmits/recei ves data but selectively reads required data only.
DTC LogicINFOID:0000000006256086
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” is previously c onducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.
>> GO TO 2.
2.CHECK DTC DETECTION
With CONSULT-III
1. Start the engine.
2. Run engine for at least 2 consecutive seconds at idle speed.
3. Perform “Self Diagnostic Results” in “E-SUS”.
Is
“U1010” detected?
YES >> Go to SCS-88, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006256087
1.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.
DTC Display itemI Malfunction detected condition Possible cause
U1010 CONTROL UNIT (CAN) Detecting error during the initial diagnosis of
CAN controller of air le
velizer control module. Air levelizer control module
Revision: 2010 May2011 QX56

POWER SUPPLY AND GROUND CIRCUITSCS-89
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POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000006256088
1.CHECK AIR LEVELIZER CONTROL MODUL E IGNITION POWER SUPPLY CIRCUIT
1. Disconnect air levelizer control module connector.
2. Turn ignition switch ON. CAUTION:
Never start the engine.
3. Check voltage between the air levelizer control module harness connector and ground.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN AI R LEVELIZER CONTROL MODULE AND IPDM E/R
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector.
3. Check continuity between air levelizer contro l module harness connector and IPDM E/R harness connec-
tor.
4. Check continuity between air levelizer control module harness connector ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK IPDM E/R
Check the IPDM E/R. Refer to PCS-10, "
Diagnosis Description".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace damaged parts.
Air levelizer control module
—Voltage
Connector Terminal
B84 9 Ground 10 – 16 V
Air levelizer control module IPDM E/R Continuity
Connector Terminal Connector Terminal
B84 9 E10 5 Existed
Air levelizer control module
—Continuity
Connector Terminal
B84 9 Ground Not 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