POWER SUPPLY AND GROUND CIRCUITSCS-17
< COMPONENT DIAGNOSIS >
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POWER SUPPLY AND GROUND CIRCUIT
SUSPENSION CONTROL UNIT
SUSPENSION CONTROL UNIT : Diagnosis ProcedureINFOID:0000000005148175
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
1.CHECK FUSES
Check that the following fuses of the sus pension control unit are not are not blown.
Are the fuses OK?
YES >> GO TO 2.
NO >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.
2.POWER SUPPLY CIRCUIT CHECK
1. Disconnect suspension control unit connector B3.
2. Check voltage between the suspension control unit connector B3 and ground.
Are the voltage results as specified?
YES >> GO TO 3.
NO >> • Check connector housings for disconnected or loose terminals. • Repair harness or connector.
3.GROUND CIRCUIT CHECK
1. Turn ignition switch OFF.
2. Check continuity between suspension control unit harness con- nector B3 and ground.
Is continuity present?
YES >> Inspection End.
NO >> Repair harness or connector.
SUSPENSION AIR COMPRESSOR
SUSPENSION AIR COMPRESSOR : Diagnosis ProcedureINFOID:0000000005148176
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
UnitTerminals Signal name Fuse No.
Suspension control unit 7
Battery power 29
6 Ignition switch ON or START 12
(+)
(-) OFF ACC ON
Connector Terminal
B3 7Ground
Battery
voltage Battery
voltage Battery
voltage
6Ground0V 0V Battery
voltage
AWEIA0114ZZ
Connector Terminal —Continuity
B3 16Ground Yes
ALEIA0028GB
Revision: April 20092010 QX56
SCS-18
< COMPONENT DIAGNOSIS >
POWER SUPPLY AND GROUND CIRCUIT
1.CHECK COMPRESSOR MOTOR RELAY OPRATION
CONSULT-III
1. Disconnect the suspension air compressor connector C9.
2. Turn ignition switch ON.
3. Select "COMPRESSOR" under AIR LEVELIZER active test items.
4. While operating the test item, check voltage at the suspension
air compressor connector C9 terminal 4.
Is battery voltage present?
YES >> GO TO 3.
NO >> GO TO 2.
2.COMPRESSOR MOTOR RELAY POWER SUPPLY CIRCUIT CHECK
1. Turn ignition switch OFF.
2. Disconnect the compressor motor relay connector.
3. Check continuity between compressor motor relay connector E131 (A) terminal 3 and suspension air compressor connector
C9 (B) terminal 4.
4. Check continuity between compressor motor relay connector E131 (A) terminal 3 and ground.
Are the continuity test results as specified?
YES >> Check compressor motor relay. Refer to SCS-20, "Diagnosis Procedure".
NO >> Repair harness or connector.
3.GROUND CIRCUIT CHECK
1. Turn ignition switch OFF.
2. Check continuity between suspension air compressor connector C9 terminals 1 and 3 and ground.
Is continuity present?
YES >> Inspection End.
NO >> Repair harness or connector.
HEIGHT SENSOR
HEIGHT SENSOR : Dia gnosis ProcedureINFOID:0000000005148177
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
(+)
(-)Voltage
Connector Terminal
C9 4Ground Battery Voltage
ALEIA0021GB
AB
Continuity
Connector Terminal Connector Terminal
E131 3 C9 4 Yes
A —Continuity
Connector Terminal
E131 3Ground No
ALEIA0022GB
Connector Terminal —Continuity
C9 1
Ground Yes
3
ALEIA0023GB
Revision: April 20092010 QX56
SCS-20
< COMPONENT DIAGNOSIS >
COMPRESSOR MOTOR RELAY
COMPRESSOR MOTOR RELAY
DescriptionINFOID:0000000005148178
Receives suspension air compressor ON signal from suspension control unit. When activated, the compressor
motor relay supplies power to the suspension air compressor.
Component Function CheckINFOID:0000000005148179
1.CHECK COMPRESSOR MOTOR RELAY OPERATION
CAUTION:
The "COMPRESSOR" active test will remain ON until it is turned off using CONSULT-III. Allowing the
compressor to run for an extended period of time may cause damage to the suspension control sys-
tem components due to excessive air pressure.
CONSULT-III
1. Turn ignition ON.
2. Select "COMPRESSOR" of AIR LEVELIZER active test items.
3. While operating test item, check that the suspension air compressor turns ON.
Does the suspension air compressor operate properly?
YES >> Compressor motor relay and suspension air compressor are operating normally.
NO >> Refer to SCS-20, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005148180
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
1.CHECK COMPRESSOR "ON" SIGNAL FROM SUSPENSION CONTROL UNIT
CONSULT-III
1. Turn ignition switch ON.
2. Disconnect compressor motor relay connector E130.
3. Select "COMPRESSOR" of AIR LEVELIZER active test items.
4. While operating test item, check voltage to compressor motor relay connector E130 terminal 2.
Is battery voltage present while operating test item?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK COMPRESSOR "ON" SIGNAL CIRCUIT ON : Compressor turns ON
OFF : Compressor turns OFF
(+)
(-)Voltage
Connector Terminal
E130 2Ground Battery voltage
ALEIA0030GB
Revision: April 20092010 QX56
HEIGHT SENSOR SIGNAL CIRCUITSCS-23
< COMPONENT DIAGNOSIS >
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HEIGHT SENSOR SIGNAL CIRCUIT
DescriptionINFOID:0000000005148181
Supplies vehicle height input to the suspension control unit.
Component Function CheckINFOID:0000000005148182
1.CHECK HEIGHT SENSOR OPERATION
CONSULT-III
1. Select "HEIGT SEN" of AIR L EVELIZER data monitor test item.
2. While monitoring test item, add or take away weight from the rear of the vehicle. Check that the voltage value changes with vehicle height.
Is the HEIGHT SEN data monitor responding normally?
YES >> Height sensor is operating normally.
NO >> Refer to SCS-23, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005148183
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
1.CHECK HEIGHT SENSOR POWER AND GROUND SUPPLY
Check height sensor power and ground supply. Refer to SCS-18, "
HEIGHT SENSOR : Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair harness or connector.
2.CHECK HEIGHT SENSOR SIGNAL CIRCUIT
1. Disconnect suspension control unit connector B3 and height sensor connector C8.
2. Check continuity between suspension control unit connector B3
(A) terminal 3 and height sensor connector C8 (B) terminal 2.
3. Check continuity between display unit harness connector B3 (A) terminal 3 and ground.
Are the continuity results as specified?
YES >> Replace the height sensor. Refer to RSU-27, "Removal and Installation".
NO >> Repair harness or connector. HEIGHT SEN : Voltage changes with vehicle height
AB
Continuity
Connector Terminal Connector Terminal
B33C 82 Y es
A —Contin u it y
Connector Terminal
B3 3Ground No
ALEIA0035GB
Revision: April 20092010 QX56
SCS-24
< COMPONENT DIAGNOSIS >
EXHAUST VALVE SOLENOID CIRCUIT
EXHAUST VALVE SOLENOID CIRCUIT
DescriptionINFOID:0000000005148184
Receives exhaust valve solenoid signal from suspension control unit. When activated, the exhaust valve sole-
noid releases air pressure from the suspension control system.
Component Function CheckINFOID:0000000005148185
1.CHECK EXHAUST SOLENOID OPERATION
CAUTION:
While operating this active test, the suspension control system will vent air pressure and the vehicle
ride height will lower. Ensure th e area around the vehicle is free fr om obstructions before beginning
test.
CONSULT-III
1. Ensure the suspension control system has air pressure and is not drooping in the rear.
2. Select "EXHAUST SOLENOID" of AIR LEVELIZER active test items.
3. While operating test item, check that the exhaust valve solenoid opens to vent air from the system. The vehicle should lower when the exhaust valve solenoid is activated.
Does the system vent properly?
YES >> Exhaust valve solenoid is operating normally.
NO >> Refer to SCS-24, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005148186
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
1.CHECK EXHAUST VALVE SOLENOID SIGNAL
CONSULT-III
1. Connect suspension control unit connector B3.
2. Turn ignition switch ON.
3. Select "EXHAUST SOLENOID" of AIR LEVELIZER active test
items.
4. While test item is operating, check signal between suspension
air compressor connector C9 terminal 2 and ground.
Is battery voltage present?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK CONTINUITY OF EXHA UST VALVE SOLENOID CIRCUIT
ON : Air vents and vehicle ride height lowers
OFF : No air vents and vehicle ride height remains constant
(+)
(-)Voltage
Connector Terminal
C9 2Ground Battery voltage
ALEIA0036GB
Revision: April 20092010 QX56
SCS-26
< COMPONENT DIAGNOSIS >
CK SUSP WARNING INDICATOR CONTROL CIRCUIT
CK SUSP WARNING INDICATOR CONTROL CIRCUIT
DescriptionINFOID:0000000005148187
The CK SUSP warning lamp is controlled by a ground signal provided to the combination meter by the sus-
pension control unit.
Component Function CheckINFOID:0000000005148188
1.CHECK WARNING LAMP OPERATION
CONSULT-III
1. Turn ignition ON.
2. Select "WARNING LAMP" of AI R LEVELIZER active test items.
3. While operating test item, check that the warning lamp activates.
Does the warning lamp operate properly?
YES >> Warning lamp is operating normally.
NO >> Refer to SCS-26, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005148189
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
1.PERFORM SUSPENSION CONTROL SYSTEM SELF-DIAGNOSIS
CONSULT-III
1. Turn ignition ON.
2. Perform SELF DIAGNOSIS functi on of AIR LEVELIZER system.
Are any DTC's present?
YES >> Refer to SCS-34, "DTC Index".
NO >> • If warning lamp is always ON, GO TO 2. • If warning lamp is always OFF, GO TO 3
2.CHECK SUSPENSION CONTROL UNI T WARNING LAMP CONTROL
1. Turn ignition OFF.
2. Disconnect the suspension control unit connector B3.
3. Turn ignition ON.
Does the CK SUSP warning lamp turn ON?
YES >> GO TO 3.
NO >> Replace the suspension control unit. Refer to RSU-26, "
Removal and Installation".
3.CHECK CONTINUITY OF WARNING LAMP CONTROL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect suspension control unit connector B3 and combina- tion meter connector M24.
3. Check continuity between suspension control unit connector B3 (A) terminal 10 and combination meter connector M24 (B) termi-
nal 15.ON : Warning lamp turns ON
OFF : Warning lamp turns OFF
AB
Continuity
Connector Terminal Connector Terminal
B3 10 M24 15 Yes
ALLIA0693GB
Revision: April 20092010 QX56
SUSPENSION CONTROL UNITSCS-29
< ECU DIAGNOSIS >
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Wiring DiagramINFOID:0000000005148191
ABEWA0028GB
Revision: April 20092010 QX56
SCS-40
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005383225
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers , always switch the Ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution for Rear SuspensionINFOID:0000000005148201
• When installing the rubber bushings, the final ti ghtening must be done under unladen condition and with the
tires on level ground. Oil will shorten the life of the r ubber bushings, so wipe off any spilled oil immediately.
• Unladen condition means the fuel tank, engine coolant and lubricants are at the full specification. The spare tire, jack, hand tools, and mats are in their designated positions.
• After installing suspension components, check the wheel alignment.
• Caulking nuts are not reusable. Always use new caulking nuts for installation. New caulking nuts are pre-
oiled, do not apply any additional lubrication.
Revision: April 20092010 QX56