INFINITI QX56 2010 Factory Service Manual

SUSPENSION CONTROL UNITSCS-29
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Wiring DiagramINFOID:0000000005148191
ABEWA0028GB
Revision: April 20092010 QX56

SCS-30
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SUSPENSION CONTROL UNIT
ABEIA0014GB
Revision: April 20092010 QX56

SUSPENSION CONTROL UNITSCS-31
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ABEIA0015GB
Revision: April 20092010 QX56

SCS-32
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SUSPENSION CONTROL UNIT
ABEIA0016GB
Revision: April 20092010 QX56

SUSPENSION CONTROL UNITSCS-33
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ABEIA0017GB
Revision: April 20092010 QX56

SCS-34
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SUSPENSION CONTROL UNIT
DTC Index
INFOID:0000000005148192
Self-diagnosis results display item
ABEIA0018GB
CONSULT-III display MalfunctionReference page
Vehicle height sensor [C1801] Vehicle height sensor voltage is less than 0.2V or greater than
4.8V for more than 60 seconds. SCS-9,
"DiagnosisProcedure".
Revision: April 20092010 QX56

SUSPENSION CONTROL UNITSCS-35
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Compressor relay [C1802] • Driving transistor for compressor relay is OFF and monitor
voltage continues at a high level for more than 10 seconds.
• Driving transistor for compressor relay is ON and monitor voltage continues at a low level for more than 5 seconds. SCS-10, "DiagnosisProcedure".
Exhaust solenoid [C1803] • Driving transistor for exhaust valve solenoid is OFF and
monitor voltage continues at a high level for more than 10
seconds.
• Driving transistor for exhaust valve solenoid is ON and mon- itor voltage continues at a low level for more than 5 seconds. SCS-11,
"DiagnosisProcedure".
Vehicle height adjusting malfunc-
tion (compressor)[C1804] Continuous compressor relay ON time is more than 120 sec-
onds. SCS-12,
"DiagnosisProcedure".
Vehicle height adjusting malfunc-
tion (exhaust solenoid)[C1805] Continuous exhaust valve solenoid ON time is more than 120
seconds. SCS-13,
"DiagnosisProcedure".
Vehicle height sensor locking mal-
function [C1806] Output sensor voltage variation
±0.02V is more than 100 sec-
onds when vehicle height range is normal. SCS-14, "
Diagnosis Proce-
dure".
Sensor 5V malfunction [C1807] Sensor reference voltage is less than 0.8V or more than 6V for
20 seconds. SCS-15,
"DiagnosisProcedure"
Integral time malfunction by sup-
plying air [C1808]A suspension air compressor ON request has been in effect
for 180 seconds and the suspension air compressor has not
activated during that time. SCS-16,
"DiagnosisProcedure".
Revision: April 20092010 QX56

SCS-36
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SUSPENSION CONTROL SYSTEM
SYMPTOM DIAGNOSIS
SUSPENSION CONTROL SYSTEM
Symptom TableINFOID:0000000005148193
AIR LEVELIZER
SymptomPossible causeReference page
Inoperative • Suspension control unit
• Compressor motor relay
• Suspension air compressorSCS-37, "
Diagnosis Proce-
dure"
System does not raise • Suspension control unit
• Height sensor
• Compressor motor relay
• Suspension air compressor
• Leak in system
• Restriction in systemSCS-38, "Diagnosis Proce-
dure"
System does not lower
• Suspension control unit
• Height sensor
• Compressor motor relay
• Suspension air compressor
• Restriction in systemSCS-39, "Diagnosis Proce-
dure"
CK SUSP indicator lamp always ON with key ON
• CK SUSP indicator la
mp control circuit
• Suspension control unit SCS-26, "Description"
Revision: April 20092010 QX56

SUSPENSION CONTROL SYSTEM INOPERATIVESCS-37
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SUSPENSION CONTROL SYSTEM INOPERATIVE
DescriptionINFOID:0000000005148194
The suspension control system does not activate. It does not raise or lower the vehicle in response to ride
height changes.
Diagnosis ProcedureINFOID:0000000005148195
1.SUSPENSION CONTROL UNIT PO WER AND GROUND INSPECTION
Check the suspension control unit power and ground supply. Refer to SCS-17, "
SUSPENSION CONTROL
UNIT : Diagnosis Procedure".
Does the suspension control uni t power and ground pass inspection?
YES >> GO TO 2.
NO >> Repair or replace the malfunctioning part.
2.CHECK HEIGHT SENSOR SIGNAL INPUT
CONSULT-III DATA MONITOR
1. Turn ignition switch ON.
2. Select "HEIGT SEN" of AI R LEVELIZER data monitor item.
3. Check the monitor status.
Is the height sensor voltage normal?
YES >> GO TO 3.
NO >> Check height sensor signal circuit. Refer to SCS-23, "
Diagnosis Procedure" .
3.CHECK GENERATOR "L" CIRCUIT SIGNAL
CONSULT-III DATA MONITOR
1. Start the engine.
2. Select "ACG L" of AIR LEVELIZER data monitor item.
3. Check the monitor status.
Is the generator "L" signal operating normally?
YES >> GO TO 4.
NO >> Check generator L circuit. Refer to CHG-12, "
Diagnosis Procedure".
4.SUSPENSION AIR COMPRESSOR POWER AND GROUND INSPECTION
Check the suspension air compressor power and ground supply. Refer to SCS-17, "
SUSPENSION AIR COM-
PRESSOR : Diagnosis Procedure".
Does the suspension air compress or power and ground pass inspection?
YES >> System is operating normally.
NO >> Repair or replace the malfunctioning part.HEIGT SEN : 0.2V - 4.8V
ACG L
: OFF with charge light OFF
: ON with charge light ON
Revision: April 20092010 QX56

SCS-38
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SUSPENSION CONTROL SYSTEM DOES NOT RAISE
SUSPENSION CONTROL SYSTEM DOES NOT RAISE
DescriptionINFOID:0000000005148196
The suspension control system does not raise t he vehicle in accordance with ride height changes.
Diagnosis ProcedureINFOID:0000000005148197
1.SUSPENSION CONTROL UNIT POWER AND GROUND INSPECTION
Check the suspension control unit power and ground supply. Refer to SCS-17, "
SUSPENSION CONTROL
UNIT : Diagnosis Procedure".
Does the suspension control unit power and ground pass inspection?
YES >> GO TO 2.
NO >> Repair or replace the malfunctioning part.
2.CHECK HEIGHT SENSOR SIGNAL INPUT
CONSULT-III DATA MONITOR
1. Turn ignition ON.
2. Select "HEIGT SEN" of AI R LEVELIZER data monitor item.
3. Check the monitor status.
Is the height sensor voltage normal?
YES >> GO TO 3.
NO >> Check height sensor signal circuit. Refer to SCS-23, "
Diagnosis Procedure" .
3.SUSPENSION AIR COMPRESSOR POWER AND GROUND INSPECTION
Check the suspension air compressor power and ground supply. Refer to SCS-17, "
SUSPENSION AIR COM-
PRESSOR : Diagnosis Procedure".
Does the suspension air compressor power and ground pass inspection?
YES >> Inspect for a weak compressor, leak or restri ction in the system. Repair or replace malfunctioning
part.
NO >> Repair or replace the malfunctioning part. HEIGT SEN
: 0.2V - 4.8V
Revision: April 20092010 QX56