2011 INFINITI QX56 air condition

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
< 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

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

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

SE-18
< SYSTEM DESCRIPTION >
SYSTEM
Malfunction Malfunctioning condition
The temperature difference between the seatback ther-
mal electric unit and seat cushion thermal electric unit is
more than 30 °C  When it detects for 4 seconds that the temperature difference between
the seatback thermal electric unit and seat cushion thermal electric unit
is more than 30 °, it stops the output to the thermal electric unit, activates
the climate controlled seat blower motor at the maximum position, and
sends the external airflow for 30 seconds
 If the temperature difference is still more than 30 °C after 30 seconds
pass, it stops all output and enters the system OFF condition
 When the temperature difference between seatback thermal electric unit and seat cushion thermal electric unit becomes less than 20 °C, the sys-
tem recovers automatically
 If it detects that the temperature difference is more than 30 °C after the
automatic system recovery, it immediately stops all output and enters the
system OFF condition
NOTE:
When the switch operation is performed before entering the system OFF
condition, the fail-safe mode is reset.
The temperature of thermal electric unit is more than
11 0 °C in the HEAT mode (any thermal electric unit in the
seatback or seat cushion)  When it detects for 4 seconds that the temperature of the thermal electric
unit is more than 110 °C, it stops the output to the thermal electric unit,
activates the climate controlled seat blower motor at the maximum posi-
tion, and sends the external airflow for 30 seconds
 If the temperature does not become less than 105 °C after 30 seconds
pass, it stops all output and enters the system OFF condition
 When the temperature of the thermal electric unit becomes less than 105 °C, the system recovers automatically
 If it detects that the temperature of the thermal electric unit is more than
11 0 °C after the automatic system recovery, it immediately stops all out-
put and enters the system OFF condition
The temperature of the thermal electric unit is more than
45 °C in the COOL mode (any thermal electric unit in the
seatback or seat cushion)  When it detects for 4 seconds that the temperature of the thermal electric
unit is more than 45 °C and less than 70 °C, it starts the temperature mon-
itoring of the thermal electric unit at 3 second intervals
 While monitoring, if it detects that the temperature continuously rises 2 °C
or more 4 times or reaches 70 °C or more, it stops all output and enters
the system OFF condition
 If it detects other results of monitoring, it continues activating in the COOL mode
Thermal electric unit sensor open circuit
(in either the back and the cushion TEU)  When it detects for 4 seconds that the thermal electric unit sensor is an
open circuit, it stops all output and enters the system OFF condition
Climate controlled seat blower motor system open circuit
(in either the back and the cushion blower)  When it detects for 2 seconds that climate controlled seat blower motor
is an open circuit while the climate controlled seat is being activated, and
the battery status has been stable for the same 2 second period. it stops
output to the thermal electric unit
 When it detects for 10 seconds that the climate controlled seat blower motor is an open circuit while the climate controlled seat is being activat-
ed, and the battery status has been stable for the same 10second period.
it stops all output and enters the system OFF condition
NOTE:
After detecting the climate seat blower motor system open circuit for 2
seconds, the system recovers automatically if the activation of the cli-
mate controlled seat blower motor is detected for 1 second or more.
Switch input out of the specified range
(either heat input or cool input)  When it detects for 4 seconds that the rotary switch input is less than
30% of the vehicle battery voltage, it stops all output and enters the sys-
tem OFF condition
 When the switch input returns to a value within the specified range, the system recovers automatically
Revision: 2010 May2011 QX56

SE-22
< ECU DIAGNOSIS INFORMATION >
CLIMATE CONTROLLED SEAT CONTROL UNIT
Malfunction Malfunctioning condition
The temperature difference between the seatback ther-
mal electric unit and seat cushion thermal electric unit is
more than 30 °C  When it detects for 4 seconds that the temperature difference between
the seatback thermal electric unit and seat cushion thermal electric unit
is more than 30 °, it stops the output to the thermal electric unit, activates
the climate controlled seat blower motor at the maximum position, and
sends the external airflow for 30 seconds
 If the temperature difference is still more than 30 °C after 30 seconds
pass, it stops all output and enters the system OFF condition
 When the temperature difference between seatback thermal electric unit and seat cushion thermal electric unit becomes less than 20 °C, the sys-
tem recovers automatically
 If it detects that the temperature difference is more than 30 °C after the
automatic system recovery, it immediately stops all output and enters the
system OFF condition
NOTE:
When the switch operation is performed before entering the system OFF
condition, the fail-safe mode is reset.
The temperature of thermal electric unit is more than
11 0 °C in the HEAT mode (any thermal electric unit in the
seatback or seat cushion)  When it detects for 4 seconds that the temperature of the thermal electric
unit is more than 110 °C, it stops the output to the thermal electric unit,
activates the climate controlled seat blower motor at the maximum posi-
tion, and sends the external airflow for 30 seconds
 If the temperature does not become less than 105 °C after 30 seconds
pass, it stops all output and enters the system OFF condition
 When the temperature of the thermal electric unit becomes less than 105 °C, the system recovers automatically
 If it detects that the temperature of the thermal electric unit is more than
11 0 °C after the automatic system recovery, it immediately stops all out-
put and enters the system OFF condition
The temperature of the thermal electric unit is more than
45 °C in the COOL mode (any thermal electric unit in the
seatback or seat cushion)  When it detects for 4 seconds that the temperature of the thermal electric
unit is more than 45 °C and less than 70 °C, it starts the temperature mon-
itoring of the thermal electric unit at 3 second intervals for increase in
temperature from the previous value
 While monitoring, if it detects that the temperature continuously rises 2 °C
or more for 4 consecutive intervals or reaches 70 °C or more, it stops all
output and enters the system OFF condition
 If it detects other results of monitoring, it continues activating in the se-
lected COOL mode
Thermal electric unit sensor open circuit
(in either the back and the cushion TEU)  When it detects for 4 seconds that the thermal electric unit sensor is an
open circuit, it stops all output and enters the system OFF condition
Climate controlled seat blower motor system open circuit
(in either the back and the cushion blower)  When it detects for 2 seconds that climate controlled seat blower motor
is an open circuit while the climate controlled seat is being activated, and
the battery status has been stable for the same 2 second period, it stops
output to the thermal electric unit
 When it detects for 10 seconds that the climate controlled seat blower motor is an open circuit while the climate controlled seat is being activat-
ed, and the battery status has been stable for the same 10second period,
it stops all output and enters the system OFF condition
NOTE:
After detecting the climate seat blower motor system open circuit for 2
seconds, the system recovers automatically if the activation of the cli-
mate controlled seat blower motor is detected for 1 second or more.
Switch input out of the specified range
(either heat input or cool input)  When it detects for 4 seconds that the rotary switch input is less than
30% of the vehicle battery voltage, it stops all output and enters the sys-
tem OFF condition
 When the switch input returns to a value within the specified range, the
system recovers automatically
Revision: 2010 May2011 QX56