air condition INFINITI QX56 2011 Factory Service Manual

U1000 CAN COMM CIRCUITSCS-87
< DTC/CIRCUIT DIAGNOSIS > [AIR LEVELIZER CONTROL SYSTEM]
C
D
F
G H
I
J
K L
M A
B
SCS
N
O P
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

SE-66
< BASIC INSPECTION >
DIAGNOSIS AND REPAIR WORK FLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORK FLOW
Work FlowINFOID:0000000006217388
DETAILED FLOW
1.OBTAIN INFORMATION ABOUT SYMPTOM
Interview the customer to obtain the malfunction information (conditions and environment when the malfunc-
tion occurred) as much as possible when the customer brings the vehicle in.
>> GO TO 2.
2.REPRODUCE THE MALFUNCTION INFORMATION
Check the malfunction on the vehicle that the customer describes.
Inspect the relation of the symptoms and the condition when the symptoms occur.
>> GO TO 3.
3.IDENTIFY THE MALFUNCTIONING SYS TEM WITH “SYMPTOM DIAGNOSIS”
Use “Symptom diagnosis” from the symptom inspection re sult in step 2 and then identify where to start per-
forming the diagnosis based on possible causes and symptoms.
>> GO TO 4.
4.IDENTIFY THE MALFUNCTIONING PART S WITH “COMPONENT DIAGNOSIS”
Perform the diagnosis with “Component diagnosis” of the applicable system.
>> GO TO 5.
5.REPAIR OR REPLACE THE MALFUNCTIONING PARTS
Repair or replace the specified malfunctioning parts.
>> GO TO 6.
6.FINAL CHECK
Check that malfunctions are not reproduced when obtaini ng the malfunction information from the customer,
referring to the symptom inspection result in step 2.
Are the malfunctions corrected?
YES >> INSPECTION END
NO >> GO TO 3.
Revision: 2010 May2011 QX56

SE-74
< DTC/CIRCUIT DIAGNOSIS >
CLIMATE CONTROLLED SEAT SWITCH
YES >> Replace climate controlled seat control unit. Refer to SE-117, "CLIMATE CONTROLLED SEAT
UNIT : Disassembly and Assembly".
NO >> Repair or replace harness.
5.CHECK CLIMATE CONTROLLED SEAT SWITCH
Check climate controlled seat switch.
Refer to SE-74, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace climate controlled seat switch. Refer to SE-147, "
Removal and Installation".
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000006217393
1.CHECK CLIMATE CONTROLLED SEAT SWITCH
1. Turn ignition switch OFF.
2. Disconnect climate controlled seat switch connector.
3. Check the continuity between climate controlled seat switch terminals under the following terminals.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace climate controlled seat switch. Refer to SE-147, "
Removal and Installation".
Terminal Condition Continuity
2 1 Climate controlled seat switch COOL mode
ON Existed
OFF Not existed
3HEAT mode ON Existed
OFF Not existed
Revision: 2010 May2011 QX56

SEATBACK THERMAL ELECTRIC UNIT SENSORSE-77
< DTC/CIRCUIT DIAGNOSIS >
C
DE
F
G H
I
K L
M A
B
SE
N
O P
SEATBACK THERMAL ELECTRIC UNIT SENSOR
Component Function CheckINFOID:0000000006217396
1.CHECK SEATBACK THERMAL ELECTRIC UNIT SENSOR FUNCTION
Check whether or not the temperatur e of the seatback thermal electric unit changes in accordance with the
HEAT or COOL switch operation of the climate controlled seat control switch.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Refer to SE-77, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217397
1.CHECK SEATBACK THERMAL ELECTRIC UNIT SENSOR SIGNAL
1. Turn ignition switch ON.
2. Check voltage between seatback thermal electric unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK SEATBACK THERMAL ELECTRIC UNIT SENSOR CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect climate controlled seat control unit c onnector and seatback thermal electric unit connector.
3. Check continuity between climate controlled s eat control unit harness connector and seatback thermal
electric unit harness connector.
4. Check continuity between climate controll ed seat control unit harness connector and ground.
Is the inspection result normal?
YES >> Replace climate controlled seat control unit.
NO >> Repair or replace harness.
3.CHECK SEATBACK THERMAL ELECTRIC UNIT SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect climate controlled seat control unit c onnector and seatback thermal electric unit connector.
3. Check continuity between climate controlled s eat control unit harness connector and seatback thermal
electric unit harness connector.
(+)
(-) Condition Voltage (V)
(Approx.)
Seatback thermal electric unit
Connector Terminal
Driver side B465 61 GroundClimate controlled seat
operated
1 - 5
Passenger side B439
Climate controlled seat control unit Seatback thermal electric unit Continuity
Connector Terminal Connector Terminal
Driver side B507 61B465
61 Existed
Passenger side B517 B439
Climate controlled seat control unit GroundContinuity
Connector Terminal
Driver side B507 61 Not existed
Passenger side B517
Revision: 2010 May2011 QX56

SEAT CUSHION THERMAL ELECTRIC UNIT SENSORSE-81
< DTC/CIRCUIT DIAGNOSIS >
C
DE
F
G H
I
K L
M A
B
SE
N
O P
SEAT CUSHION THERMAL ELECTRIC UNIT SENSOR
Component Function CheckINFOID:0000000006217401
1.CHECK SEAT CUSHION THERMAL ELECTRIC UNIT SENSOR FUNCTION
Check whether or not the temperature of the seat cush ion thermal electric unit changes in accordance with the
HEAT or COOL switch operation of the climate controlled seat control switch.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Refer to SE-81, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217402
1.CHECK SEAT CUSHION THERMAL ELECTRIC UNIT SENSOR SIGNAL
1. Turn ignition switch ON.
2. Check voltage between seat cushion ther mal electric unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK SEAT CUSHION THERMAL ELECTRIC UNIT SENSOR CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect climate controlled seat control unit connec tor and seat cushion thermal electric unit connector.
3. Check continuity between climate controlled seat control unit harness connector and seat cushion thermal
electric unit harness connector.
4. Check continuity between climate controll ed seat control unit harness connector and ground.
Is the inspection result normal?
YES >> Replace climate controlled seat control unit.
NO >> Repair or replace harness.
3.CHECK SEAT CUSHION THERMAL ELEC TRIC UNIT SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect climate controlled seat control unit connec tor and seat cushion thermal electric unit connector.
3. Check continuity between climate controlled seat control unit harness connector and seat cushion thermal
electric unit harness connector.
(+)
(-) Condition Voltage (V)
(Approx.)
Seat cushion thermal electric unit
Connector Terminal
Driver side B505 70 GroundClimate controlled seat
operated
1 - 5
Passenger side B515
Climate controlled seat control unit Seat cushion thermal electric unit Continuity
Connector Terminal Connector Terminal
Driver side B509 70B505
70 Existed
Passenger side B519 B515
Climate controlled seat control unit GroundContinuity
Connector Terminal
Driver side B509 70 Not existed
Passenger side B519
Revision: 2010 May2011 QX56

CLIMATE CONTROLLED SEATBACK BLOWER MOTORSE-83
< DTC/CIRCUIT DIAGNOSIS >
C
DE
F
G H
I
K L
M A
B
SE
N
O P
CLIMATE CONTROLLED SEATBACK BLOWER MOTOR
Component Function CheckINFOID:0000000006217404
1.CHECK CLIMATE CONTROLLED SEA TBACK BLOWER MOTOR FUNCTION
When turning the climate controlled seat switch to the HEAT or COOL mode position, check that the climate
controlled seatback blower is operated in each specific mode.
Is the inspection result normal?
YES >> Climate controlled seatback blower motor is OK.
NO >> Refer to SE-83, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217405
1.CHECK CLIMATE CONTROLLED SEATBAC K BLOWER MOTOR POWER SUPPLY
1. Turn ignition switch ON.
2. Check voltage between climate controlled s eatback blower motor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK CLIMATE CONTROLLE D SEATBACK BLOWER MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect climate controlled seatback blower moto r connector and climate controlled seat control unit
connector.
3. Check continuity between climate controlled seat back blower motor harness connector and climate con-
trolled seat control unit harness connector.
4. Check continuity between climate controlled seatback blower motor harness connector and ground.
Is the inspection result normal?
YES >> Replace climate controlled seat control unit. Refer to SE-117, "CLIMATE CONTROLLED SEAT
UNIT : Disassembly and Assembly".
NO >> Repair or replace harness.
(+)
(–) Condition Voltage (V)
(Approx.)
Climate controlled seatback blower motor
Connector Terminal
Driver side B466 62 GroundClimate controlled seat
switch
HEAT mode
12
COOL mode
Other than above 0
Passenger side B440 Climate controlled seat
switchHEAT mode
12
COOL mode
Other than above 0
Climate controlled seatback blower motor Climate controlled seat control unit Continuity
Connector Terminal Connector Terminal
Driver side B466 62B507
62 Existed
Passenger side B440 B517
Climate controlled seatback blower motor
GroundContinuity
Connector Terminal
Driver side B466 62 Not existed
Passenger side B440
Revision: 2010 May2011 QX56

SE-84
< DTC/CIRCUIT DIAGNOSIS >
CLIMATE CONTROLLED SEATBACK BLOWER MOTOR
3.CHECK CLIMATE CONTROLLED SEATBACK BLOWER MOTOR SPEED CONTROL SIGNAL
Check voltage between climate controlled seat back blower motor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK CLIMATE CONTROLLED SEATBACK BLOWER MOTOR SPEED CONTROL SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect climate controlled seatback blower moto r connector and climate controlled seat control unit
connector.
3. Check continuity between climate controlled seat back blower motor harness connector and climate con-
trolled seat control unit harness connector.
4. Check continuity between climate controlled seatback blower motor harness connector and ground.
Is the inspection result normal?
YES >> Replace climate controlled seat control unit. Refer to SE-117, "CLIMATE CONTROLLED SEAT
UNIT : Disassembly and Assembly".
NO >> Repair or replace harness.
5.CHECK CLIMATE CONTROLLED SEATBACK BLOWER MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect climate controlled seatback blower moto r and climate controlled seat control unit connector.
3. Check continuity between climate controlled seat back blower motor harness connector and climate con-
trolled seat control unit harness connector.
(+)
(–) Condition Voltage (V)
(Approx.)
Climate controlled seatback blower motor
Connector Terminal
Driver side B466 63 GroundClimate controlled seat
switch
HEAT 5.5 - 8
COOL
HI 11.2
MID 8
LO 6.5
Other than above 0
Passenger side B440 Climate controlled seat
switchHEAT 5.5 - 8
COOL
HI 11.2
MID 8
LO 6.5
Other than above 0
Climate controlled seatback blower motor Climate controlled seat control unit Continuity
Connector Terminal Connector Terminal
Driver side B466 63B507
63 Existed
Passenger side B440 B517
Climate controlled seatback blower motor
GroundContinuity
Connector Terminal
Driver side B466 63 Not existed
Passenger side B440
Revision: 2010 May2011 QX56