air conditioning INFINITI QX56 2011 Factory Service Manual

HAC-72
< DTC/CIRCUIT DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
U1000 CAN COMM CIRCUIT
DTC/CIRCUIT DIAGNOSIS
U1000 CAN COMM CIRCUIT
DescriptionINFOID:0000000006275903
CAN (Controller Area Network) is a serial communication
system for real time application. It is an on-vehicle
multiplex communication system with high data comm unication speed and excellent error detection ability.
Many electronic control units are equipped onto vehicl es, and each control unit shares information and links
with other control units during operation (not independent ). In CAN communication, control units are con-
nected with two 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.
CAN Communication Signal Chart. Refer to LAN-28, "
CAN COMMUNICATION SYSTEM : CAN Communica-
tion Signal Chart".
DTC LogicINFOID:0000000006275904
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PERFORM SELF-DIAGNOSIS
With CONSULT-III
1. Turn ignition switch ON and wait for 2 seconds or more.
2. Select “Self Diagnostic Result” m ode of “HVAC” using CONSULT-.III
3. Check DTC.
Is DTC detected?
YES >> Refer to HAC-72, "Diagnosis Procedure".
NO >> Refer to GI-40, "
Intermittent Incident".
Diagnosis ProcedureINFOID:0000000006275905
1.CHECK CAN COMMUNICATION SYSTEM
Check CAN communication system. Refer to LAN-18, "
Trouble Diagnosis Flow Chart".
>> INSPECTION END
DTC Items
(CONSULT-III screen terms) DTC detection condition Possible cause
U1000 CAN COMM CIRCUIT When A/C auto amp. is not transmitting
or receiving CAN communication signal
for 2 or more seconds.
CAN communication system
Revision: 2010 May2011 QX56

U1010 CONTROL UNIT (CAN)HAC-73
< DTC/CIRCUIT DIAGNOSIS > [AUTOMATIC AIR CONDITIONING]
C
D
E
F
G H
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K L
M A
B
HAC
N
O P
U1010 CONTROL UNIT (CAN)
DescriptionINFOID:0000000006275906
Initial diagnosis of A/C auto amp.
DTC LogicINFOID:0000000006275907
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PERFORM SELF-DIAGNOSIS
With CONSULT-III
1. Turn ignition switch ON.
2. Select “Self Diagnostic Result” m ode of “HVAC” using CONSULT-.III
3. Check DTC.
Is DTC detected?
YES >> Refer to HAC-73, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006275908
1.REPLACE A/C AUTO AMP.
Replace A/C auto amp.. Refer to HAC-146, "
Removal and Installation".
>> INSPECTION END
DTC Items
(CONSULT-III screen terms) DTC detection condition Possible cause
U1010 CONTROL UNIT (CAN) When detecting error during the initial diag-
nosis of CAN controller of A/C auto amp.A/C auto amp.
Revision: 2010 May2011 QX56

HAC-74
< DTC/CIRCUIT DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
B2578, B2579 FRONT IN-VEHICLE SENSOR
B2578, B2579 FRONT IN-VEHICLE SENSOR
DTC LogicINFOID:0000000006275909
DTC DETECTION LOGIC
NOTE:
 If DTC is displayed along with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to
HAC-
72, "DTC Logic".
 If DTC is displayed along with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer to HAC-
73, "DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn ignition switch ON.
2. Select “Self Diagnostic Result” m ode of “HVAC” using CONSULT-III.
3. Check DTC.
Is DTC detected?
YES >> Refer to HAC-106, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006275910
1.CHECK FRONT IN-VEHICLE SENSOR POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect front in-vehicle sensor connector.
3. Turn ignition switch ON.
4. Check voltage between front in-vehicle sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK FRONT IN-VEHCLE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between front in-vehicle sensor harness connector and A/C auto amp. harness connec-
tor.
Is the inspection result normal?
DTC Items
(CONSULT-III screen terms) DTC detection condition Possible cause
B2578 IN-VEHICLE SENSOR The front in-vehicle sensor recognition temper-
ature is too high.
 Front in-vehicle sensor
 A/C auto amp.
 Harness or connectors
(The sensor circuit is open or short-
ed.)
B2579
The front in-vehicle sensor recognition temper-
ature is too low.
+
−Voltage
(Approx.)
Front in-vehicle sensor
Connector Terminal M73 1 Ground 5 V
Front in-vehicle sensor —Continuity
Connector Terminal
M73 2 Ground Existed
Revision: 2010 May2011 QX56

B2578, B2579 FRONT IN-VEHICLE SENSORHAC-75
< DTC/CIRCUIT DIAGNOSIS > [AUTOMATIC AIR CONDITIONING]
C
D
E
F
G H
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K L
M A
B
HAC
N
O P
YES >> GO TO 3.
NO >> Repair harness or connector.
3.CHECK FRONT IN-VEHICLE SENSOR
Check front in-vehicle sensor. Refer to HAC-107, "
Component Inspection".
Is the inspection result normal?
YES >> Replace A/C auto amp.. Refer to HAC-146, "Removal and Installation".
NO >> Replace front in-vehicle sensor. Refer to HAC-148, "
FRONT A/C UNIT ASSEMBLY : Removal
and Installation".
4.CHECK FRONT IN-VEHCLE SENSOR POWER SUPPLY CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between front in-vehicle sens or harness connector and A/C auto amp. harness connec-
tor.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair harness or connector.
5.CHECK FRONT IN-VEHCLE SENSOR POWER SUPPLY CIRCUIT FOR GROUND SHORT
Check continuity between front in-vehicle sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair harness or connector.
6.CHECK FRONT IN-VEHICLE SENSOR PO WER SUPPLY CIRCUIT FOR POWER SHORT
1. Turn ignition switch ON.
2. Check voltage between front in-vehicle sensor harness connector and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp.. Refer to HAC-146, "Removal and Installation".
NO >> Repair harness or connector.
Component InspectionINFOID:0000000006275911
1.CHECK FRONT IN-VEHICLE SENSOR
1. Turn ignition switch OFF.
2. Disconnect front in-vehicle sensor connector.
3. Check resistance between front in-vehicle sensor terminals.
Front in-vehicle sensor A/C auto amp. Continuity
Connector Terminal Connector Terminal
M73 1 M50 27 Existed
Front in-vehicle sensor —Continuity
Connector Terminal
M73 1 Ground Not existed
+ −Vol tag e
(Approx.)
Front in-vehicle sensor
Connector Terminal M73 1 Ground 0 V
Revision: 2010 May2011 QX56

HAC-76
< DTC/CIRCUIT DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
B2578, B2579 FRONT IN-VEHICLE SENSOR
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace front in-vehicle sensor. Refer to
HAC-148, "
FRONT A/C UNIT ASSEMBLY : Removal
and Installation".
Te r m i n a lCondition
Resistance: kΩ
Temperature: °C ( °F)
12 −
15 (5) 12.73
− 10 (14) 9.92
− 5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27 45 (113) 1.07
Revision: 2010 May2011 QX56

B257B, B257C AMBIENT SENSORHAC-77
< DTC/CIRCUIT DIAGNOSIS > [AUTOMATIC AIR CONDITIONING]
C
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G H
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K L
M A
B
HAC
N
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B257B, B257C AMBIENT SENSOR
DTC LogicINFOID:0000000006275912
DTC DETECTION LOGIC
NOTE:
 If DTC is displayed along with DTC U1000, first per form the trouble diagnosis for DTC U1000. Refer to HAC-
72, "DTC Logic".
 If DTC is displayed along with DTC U1010, fi rst perform the trouble diagnosis for DTC U1010. HAC-73,
"DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn ignition switch ON.
2. Select “Self Diagnostic Result” m ode of “HVAC” using CONSULT-III.
3. Check DTC.
Is DTC detected?
YES >> Refer to HAC-77, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006275913
1.CHECK AMBIENT SENSOR POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ambient sensor connector.
3. Turn ignition switch ON.
4. Check voltage between ambient sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK AMBIENT SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp.connector.
3. Check continuity between ambient sensor har ness connector and A/C auto amp. harness connector.
Is the inspection result normal?
DTC Items
(CONSULT-III screen terms) DTC detection condition Possible cause
B257B AMBIENT SENSOR The ambient sensor recognition temperature is
too high.
 Ambient sensor
 A/C auto amp.
 Harness or connectors
(The sensor circuit is open or short-
ed.)
B257C
The ambient sensor recognition temperature is
too low.
+
−Vol tag e
(Approx.)
Ambient sensor
Connector Terminal E76 1 Ground 5 V
Ambient sensor —Continuity
Connector Terminal
E76 2 Ground Existed
Revision: 2010 May2011 QX56

HAC-78
< DTC/CIRCUIT DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
B257B, B257C AMBIENT SENSOR
YES >> GO TO 3.
NO >> Repair harness or connector.
3.CHECK AMBIENT SENSOR
Check ambient sensor. Refer to HAC-78, "
Component Inspection".
Is the inspection result normal?
YES >> Replace A/C auto amp.. Refer to HAC-146, "Removal and Installation".
NO >> Replace ambient sensor. Refer to HAC-147, "
Removal and Installation".
4.CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp.connector.
3. Check continuity between ambient sensor har ness connector and A/C auto amp. harness connector.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair harness or connector.
5.CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR GROUND SHORT
Check continuity between ambient sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair harness or connector.
6.CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR POWER SHORT
1. Turn ignition switch ON.
2. Check voltage between ambient sensor harness connector and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp.. Refer to HAC-146, "Removal and Installation".
NO >> Repair harness or connector.
Component InspectionINFOID:0000000006275914
1.CHECK AMBIENT SENSOR
1. Turn ignition switch OFF.
2. Disconnect ambient sensor connector.
3. Check resistance between ambient sensor terminals.
Ambient sensor A/C auto amp. Continuity
Connector Terminal Connector Terminal
E76 1 M50 7 Existed
Ambient sensor —Continuity
Connector Terminal
E76 1 Ground Not existed
+ −Voltage
(Approx.)
Ambient sensor
Connector Terminal E76 1 Ground 0 V
Revision: 2010 May2011 QX56

B257B, B257C AMBIENT SENSORHAC-79
< DTC/CIRCUIT DIAGNOSIS > [AUTOMATIC AIR CONDITIONING]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ambient sensor. Refer to HAC-147, "
Removal and Installation".
Te r m i n a lCondition
Resistance: kΩ
Temperature: °C ( °F)
12 −
15 (5) 12.73
− 10 (14) 9.92
− 5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27 45 (113) 1.07
Revision: 2010 May2011 QX56

HAC-80
< DTC/CIRCUIT DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
B2581, B2582 INTAKE SENSOR
B2581, B2582 INTAKE SENSOR
DTC LogicINFOID:0000000006275915
DTC DETECTION LOGIC
NOTE:
 If DTC is displayed along with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to
HAC-
72, "DTC Logic".
 If DTC is displayed along with DTC U1010, fi rst perform the trouble diagnosis for DTC U1010. HAC-73,
"DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn ignition switch ON.
2. Select “Self Diagnostic Result” m ode of “HVAC” using CONSULT-III.
3. Check DTC.
Is DTC detected?
YES >> Refer to HAC-80, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006275916
1.CHECK INTAKE SENSOR POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect intake sensor connector.
3. Turn ignition switch ON.
4. Check voltage between intake sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK INTAKE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between intake sensor har ness connector and A/C auto amp. harness connector.
Is the inspection result normal?
DTC Items
(CONSULT-III screen terms) DTC detection condition Possible cause
B2581 INTAKE SENSOR The intake sensor recognition temperature is
too high.
 Intake sensor
 A/C auto amp.
 Harness or connectors
(The sensor circuit is open or short-
ed.)
B2582
The intake sensor recognition temperature is
too low.
+
−Voltage
(Approx.)
Intake sensor
Connector Terminal M257 1 Ground 5 V
Intake sensor —Continuity
Connector Terminal
M257 2 Ground Existed
Revision: 2010 May2011 QX56

B2581, B2582 INTAKE SENSORHAC-81
< DTC/CIRCUIT DIAGNOSIS > [AUTOMATIC AIR CONDITIONING]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
YES >> GO TO 3.
NO >> Repair harness or connector.
3.CHECK INTAKE SENSOR
Check intake sensor. Refer to HAC-81, "
Component Inspection".
Is the inspection result normal?
YES >> Replace A/C auto amp.. Refer to HAC-146, "Removal and Installation".
NO >> Replace intake sensor. Refer to HAC-150, "
Removal and Installation".
4.CHECK INTAKE SENSOR POWER SUPPLY CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between intake sensor har ness connector and A/C auto amp. harness connector.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair harness or connector.
5.CHECK INTAKE SENSOR POWER SU PPLY CIRCUIT FOR GROUND SHORT
Check continuity between intake sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair harness or connector.
6.CHECK INTAKE SENSOR POWER SU PPLY CIRCUIT FOR POWER SHORT
1. Turn ignition switch ON.
2. Check voltage between intake sensor harness connector and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp.. Refer to HAC-146, "Removal and Installation".
NO >> Repair harness or connector.
Component InspectionINFOID:0000000006275917
1.CHECK INTAKE SENSOR
1. Turn ignition switch OFF.
2. Disconnect intake sensor connector.
3. Check resistance between intake sensor terminals.
Intake sensor A/C auto amp. Continuity
Connector Terminal Connector Terminal
M257 1 M50 28 Existed
Intake sensor —Continuity
Connector Terminal
M257 1 Ground Not existed
+ −Vol tag e
(Approx.)
Intake sensor
Connector Terminal M257 1 Ground 0 V
Revision: 2010 May2011 QX56