display INFINITI QX56 2008 Factory Service Manual

C1803 EXHAUST SOLENOIDSCS-11
< COMPONENT DIAGNOSIS >
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C1803 EXHAUST SOLENOID
DescriptionINFOID:0000000001731966
The exhaust valve solenoid controls the vent function of the suspensi on control system. The exhaust valve
solenoid is built into the suspension air compressor. The suspension control unit supplies voltage to the
exhaust valve solenoid to activate it.
DTC LogicINFOID:0000000001731967
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001731968
1.CHECK EXHAUST SOLENOID OPERATION
CAUTION:
While operating this active test, the suspension control system wil l vent air pressure and the vehicle
ride height will lower. Ensure th e area around the vehicle is free from 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 va lve 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-23, "
Description"
DTCDisplay contents of CON-
SULT-III Diagnostic item is detected when ...
Probable malfunction location
C1803 EXHAUST SOLENOID • Driving transistor for the exhaust valve sole-
noid is OFF and monitor voltage continues at
a high level for more than 10 seconds.
• Driving transistor for the exhaust valve sole-
noid is ON and monitor voltage continues at
a low level for more than 5 seconds. Open or short circuit in the exhaust valve sole-
noid control circuit. Refer to
SCS-23, "
Compo-
nent Function Check"
ON : Air vents and vehicle ride height lowers
OFF : No air vents and vehicle ride height remains constant
Revision: March 2010 2008 QX56

SCS-12
< COMPONENT DIAGNOSIS >
C1804 HEIGHT ADJUSTING MALFUNCTION (COMPRESSOR)
C1804 HEIGHT ADJUSTING MA LFUNCTION (COMPRESSOR)
DescriptionINFOID:0000000001731969
The compressor motor relay is controlled by the sus pension control unit. The suspension control unit supplies
voltage to the coil side of the relay to activate it. T he compressor motor relay, when activated, supplies power
to the suspension air compressor.
DTC LogicINFOID:0000000001731970
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001731971
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 air levelizer system com-
ponents 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"
DTCDisplay contents of CON-
SULT-III Diagnostic item is detected when ...
Probable malfunction location
C1804 VEHICLE HEIGHT AD-
JUSTING MALFUNC-
TION (COMPRESSOR) Continuous compressor relay ON time is more
than 120 seconds.
Compressor motor relay. Refer to
SCS-20,
"Component Function Check"
ON : Compressor turns ON
OFF : Compressor turns OFF
Revision: March 2010 2008 QX56

C1805 HEIGHT ADJUSTING MALFUNCTION (EXH SOLENOID)
SCS-13
< COMPONENT DIAGNOSIS >
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C1805 HEIGHT ADJUSTING MALF UNCTION (EXH SOLENOID)
DescriptionINFOID:0000000001731972
The exhaust valve solenoid controls the vent function of the suspensi on control system. The exhaust valve
solenoid is built into the suspension air compressor. The suspension control unit supplies voltage to the
exhaust valve solenoid to activate it.
DTC LogicINFOID:0000000001731973
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001731974
1.CHECK EXHAUST SOLENOID OPERATION
CAUTION:
While operating this active test, the suspension control system wil l vent air pressure and the vehicle
ride height will lower. Ensure th e area around the vehicle is free from 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 va lve 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-23, "
Description"
DTCDisplay contents of CON-
SULT-III Diagnostic item is detected when ...
Probable malfunction location
C1805 VEHICLE HEIGHT AD-
JUSTING MALFUNC-
TION (EXHAUST
SOLENOID) Continuous exhaust valve solenoid ON time is
more than 120 seconds.
Short to power in the exhaust valve solenoid
control circuit. Refer to
SCS-23, "
Component
Function Check"
ON : Air vents and vehicle ride height lowers
OFF : No air vents and vehicle ride height remains constant
Revision: March 2010 2008 QX56

SCS-14
< COMPONENT DIAGNOSIS >
C1806 VEHICLE HEIGHT SENSOR LOCKING MALFUNCTION
C1806 VEHICLE HEIGHT SENSOR LOCKING MALFUNCTION
DescriptionINFOID:0000000001731975
The vehicle height sensor operates on a 5 volt referenc e signal from the suspension control unit. The suspen-
sion control unit also provides ground to the height sensor.
DTC LogicINFOID:0000000001731976
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001731977
1.CHECK HEIGHT SENSOR OPERATION
CONSULT-III
1. Turn ignition switch ON
2. Select "HEIGT SEN" of AIR LEVELIZER data monitor test item.
Is the HEIGHT SEN voltage within the given range?
YES >> Height sensor is operating normally.
NO >> Refer to SCS-22, "
Diagnosis Procedure".
DTCDisplay contents of CON-
SULT-III Diagnostic item is detected when ...
Probable malfunction location
C1806 VEHICLE HEIGHT SEN-
SOR LOCKING MAL-
FUNCTION Output sensor voltage variation
±0.02V is more
than 100 seconds when vehicle height range is
normal. • Height sensor power/ground supply. Refer to
SCS-18, "
HEIGHT SENSOR : Diagnosis
Procedure"
• Charging system malfunction. Refer to CHG-
10, "Inspection Procedure"
HEIGHT SEN : 0.2V - 4.8V with no more than ± 0.02V
variation
Revision: March 2010 2008 QX56

C1807 SENSOR 5V MALFUNCTIONSCS-15
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C1807 SENSOR 5V MALFUNCTION
DescriptionINFOID:0000000001731978
The vehicle height sensor operates on a 5 volt referenc e signal from the suspension control unit. The suspen-
sion control unit also provides ground to the height sensor.
DTC LogicINFOID:0000000001731979
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001731980
1.POWER SUPPLY CIRCUIT CHECK
1. Disconnect height sensor connector C8.
2. Turn the ignition switch ON.
3. Check voltage between the height sensor connector C8 terminal 1 and ground.
Is 5V present?
YES >> System is working normally.
NO >> Check harness or connector for open or short. If OK, replace the suspension control unit. Refer to RSU-25, "
Removal and Installation"
DTCDisplay contents of CON-
SULT-III Diagnostic item is detected when ...
Probable malfunction location
C1807 SENSOR 5V MALFUNC-
TION Sensor reference voltage is less than 0.8V or
more than 6V for 20 seconds. • Height sensor power/ground supply. Refer to
SCS-18, "
HEIGHT SENSOR : Diagnosis
Procedure"
• Charging system malfunction. Refer to CHG-
10, "Inspection Procedure"
(+)
(-) Voltage
Connector Terminal
C8 1 Ground 5V
ALEIA0026GB
Revision: March 2010 2008 QX56

SCS-16
< COMPONENT DIAGNOSIS >
C1808 INTEGRAL TIME MALFUNCTION SUPPLYING AIR
C1808 INTEGRAL TIME MALFUNCTION SUPPLYING AIR
DescriptionINFOID:0000000001731981
The suspension air compressor is supplied power by the compressor motor relay. The suspension control unit
supplies power to the compressor motor relay in order to activate the relay and subsequently activate the sus-
pension air compressor.
DTC LogicINFOID:0000000001731982
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001731983
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 air levelizer system com-
ponents 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"
DTCDisplay contents of CON-
SULT-III Diagnostic item is detected when ...
Probable malfunction location
C1808 INTEGRAL TIME MAL-
FUNCTION SUPPLYING
AIR A suspension air compressor ON request has
been in effect for 180 seconds and the suspen-
sion air compressor has not activated during
that time. • Compressor motor relay. Refer to
SCS-20,
"Diagnosis Procedure"
• Suspension air compressor. Refer to SCS-
17, "SUSPENSION AIR COMPRESSOR :
Diagnosis Procedure"
ON : Compressor turns ON
OFF : Compressor turns OFF
Revision: March 2010 2008 QX56

SCS-22
< COMPONENT DIAGNOSIS >
HEIGHT SENSOR SIGNAL CIRCUIT
HEIGHT SENSOR SIGNAL CIRCUIT
DescriptionINFOID:0000000001731990
Supplies vehicle height input to the suspension control unit.
Component Function CheckINFOID:0000000001731991
1.CHECK HEIGHT SENSOR OPERATION
CONSULT-III
1. Select "HEIGT SEN" of AIR LEVELIZER data monitor test item.
2. While monitoring test item, add or take away weight from the rear of the vehi cle. 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-22, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001731992
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-26, "Removal and Installation"
NO >> Repair harness or connector.HEIGHT SEN : Voltage changes with vehicle height
AB
Continuity
Connector Terminal Connector Terminal
B33C82 Yes
A —Continuity
Connector Terminal
B3 3Ground No
ALEIA0035GB
Revision: March 2010 2008 QX56

SUSPENSION CONTROL UNITSCS-33
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DTC IndexINFOID:0000000001732001
Self-diagnosis results display item
ALEIA0043GB
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: March 2010
2008 QX56

SEC-4
< BASIC INSPECTION >[WITH INTELLIGENT KEY SYSTEM]
DIAGNOSIS AND REPAIR WORKFLOW
1.GET INFORMATION FOR SYMPTOM
Get the detailed information from the customer about the symptom (the condition and the environment when
the incident/malfunction occurred).
>> GO TO 2
2.CHECK DTC
1. Check DTC for Intelligent Key unit and BCM.
2. Perform the following procedure if DTC is displayed.
- Erase DTC.
- Study the relationship between the cause detected by DTC and the symptom described by the customer.
3. Check related service bulletins for information.
Is any symptom described and any DTC detected?
Symptom is described, DTC is displayed>>GO TO 3
Symptom is described, DTC is not displayed>>GO TO 4
Symptom is not described, DTC is displayed>>GO TO 5
3.CONFIRM THE SYMPTOM
Confirm the symptom described by the customer.
Connect CONSULT-III to the vehicle in “DATA MO NITOR” mode and check real-time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 5
4.CONFIRM THE SYMPTOM
Confirm the symptom described by the customer.
Connect CONSULT-III to the vehicle in “DATA MO NITOR ” mode and check real-time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 6
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC Confirmation Procedure for the display ed DTC, and then check that DTC is detected again.
If two or more DTCs are detected, refer to SEC-97, "
DTCInspectionPriorityChart" (Intelligent Key unit),
SEC-79, "
DTCInspectionPriorityChart" (BCM) and determine trouble diagnosis order.
Is DTC detected?
YES >> GO TO 8
NO >> Refer to GI-38, "
Intermittent Incident".
6.PERFORM BASIC INSPECTION
Perform Basic Inspection. Refer to SEC-6, "
Basic Inspection".
>> GO TO 7
7.DETECT MALFUNCTIONING SYSTEM BY SYMPTOM TABLE
Detect malfunctioning system according to Symptom Table based on the confirmed symptom in step 4.
>> GO TO 8
8.DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.
NOTE:
The Diagnostic Procedure is described based on open circuit inspection. A short circuit inspection is also
required for the circuit check in the Diagnostic Procedure.
>> GO TO 9
Revision: March 2010 2008 QX56

DIAGNOSIS AND REPAIR WORKFLOWSEC-5
< BASIC INSPECTION > [WITH INTELLIGENT KEY SYSTEM]
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9.REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replace-
ment.
3. Check DTC. If DTC is displayed, erase it.
>> GO TO 10
10.FINAL CHECK
When DTC was detected in step 9, perform DTC Confirmation Procedure or Component Function Check
again, and then check that the malfunctions have been fully repaired.
When symptom was described by the customer, refer to the confirmed symptom in step 3 or 4, and check that
the symptom is not detected.
Does the symptom reappear?
YES (DTC is detected)>>GO TO 8
YES (Symptom remains)>>GO TO 6
NO >> Inspection End.
Revision: March 2010 2008 QX56