INFINITI QX56 2008 Factory Service Manual

HAC-18
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AUTOMATIC AIR CONDITIONER SYSTEM
Switches And Their Control Function (Rear)
INFOID:0000000001679775
AWIIA0275GB
AWIIA0084GB
Revision: March 2010 2008 QX56

CAN COMMUNICATION SYSTEMHAC-19
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CAN COMMUNICATION SYSTEM
System DescriptionINFOID:0000000001679776
Refer to LAN-4, "System Description".
Revision: March 2010 2008 QX56

HAC-20
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
DIAGNOSIS SYSTEM (HVAC)
DIAGNOSIS SYSTEM (HVAC)
CONSULT-III Function (HVAC)INFOID:0000000001679777
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
SELF-DIAGNOSIS
Display Item List
DATA MONITOR
Display Item List
Diagnostic mode
Description
SELF-DIAG RESULTS Displays A/C au to amp. self-diagnosis results.
DATA MONITOR Displays A/C auto amp. input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read. ECU PART NUMBER A/C auto amp. part number can be read.
DTC Description
Reference page
B2573 Battery voltage out of range CHG-10, "
Inspection Procedure"
B2578 In-vehicle sensor circuit out of range (low)
HAC-81, "In-Vehicle Sensor Diagnosis Procedure"B2579 In-vehicle sensor circuit out of range (high)
B257B Ambient sensor circuit short HAC-78, "
Ambient Sensor Diagnosis Procedure"B257C Ambient sensor circuit open
B257F Optical sensor (Driver) circuit open or short HAC-84, "
Optical Sensor Diagnosis Procedure".
B2580 Optical sensor (Passenger) circuit open or short
B2581 Intake sensor circuit short HAC-86, "
Intake Sensor Diagnosis Procedure"B2582 Intake sensor circuit open
U1000 CAN bus fault LAN-14, "
Trouble Diagnosis Flow Chart"
Monitor itemValue Contents
BATT VIA CAN "V" Displays battery voltage signal.
IGN VIA CAN "ON/OFF" Displays ignition switch signal.
DVR SUNLD SEN "w/m2" Displays optical sensor (driver) signal.
PAS SUNLD SEN "w/m2" Displays optical sensor (passenger) signal.
AMB TEMP SEN "° C" Displays ambient sensor signal.
EVAP TEMP SEN "° C" Displays intake sensor signal.
INCAR TMP SEN "° C" Displays in-vehicle sensor signal.
RR TEMPSET FR "V" Displays air mix door (front) set point signal.
RR TEMPSET RR "V" Displays air mix door (rear) set point signal.
MODE FDBCK "V" Displays mode door motor feedback signal.
DVR MIX FDBCK "V" Displays air mix door motor (driver) feedback signal.
PAS MIX FDBCK "V" Displays air mix door motor (passenger) feedback signal.
RR FDBCK "V" Displays air mix door motor (rear) feedback signal.
DEF FDBCK "V" Displays defroster door motor feedback signal.
Revision: March 2010 2008 QX56

DIAGNOSIS SYSTEM (BCM)HAC-21
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DIAGNOSIS SYSTEM (BCM)
CONSULT-III Function (BCM)INFOID:0000000001679778
CONSULT-III can display each diagnostic item us ing the diagnostic test modes shown following.
DATA MONITOR
Display Item List
BCM diagnostic
test item Diagnostic mode
Description
Inspection by part WORK SUPPORT
Supports inspections and adjustments. Commands are transmitted to the BCM for
setting the status suitable for required operation, input/output signals are received
from the BCM and received data is displayed.
DATA MONITOR Displays BCM input/output data in real time. ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
SELF-DIAG RESULTS Displays BCM self-diagnosis results.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read. ECU PART NUMBER BCM part number can be read.
CONFIGURATION Performs BCM configuration read/write functions.
Monitor item name “operation or unit” Contents
IGN ON SW “ON/OFF” Displays “IGN Position (ON)/OFF, ACC Position (OFF)” status as judged from ignition switch signal.
COMP ON SIG “ON/OFF” Displays “COMP (ON)/COMP (OFF)” stat us as judged from air conditioner switch signal.
FAN ON SIG “ON/OFF” Displays “FAN (ON)/FAN (OFF)” status as judged from blower motor switch signal.
Revision: March 2010 2008 QX56

HAC-22
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
SELF-DIAGNOSIS FUNCTION
SELF-DIAGNOSIS FUNCTION
A/C Auto Amp. Self-DiagnosisINFOID:0000000001679779
A/C SYSTEM SELF-DIAGNOSIS FUNCTION
The self-diagnosis function is built into the A/C aut
o amp. to quickly locate the cause of malfunctions.
DESCRIPTION
The self-diagnostic system diagnoses sensors, CAN sys tem, and battery voltage on A/C auto amp. Refer to
applicable sections (items) for details. Fault codes (if any are present) will be displayed in the ambient temper-
ature display area. Refer to HAC-23, "
A/C System Self-Diagnosis Code Chart".
SELF-DIAGNOSTIC MODE
NOTE:
Radio must be off.
1. On the A/C and AV switch asse mbly, press the "SETTING" but-
ton and twist the volume knob clockwise and counterclockwise
until the Self-Diagnosis screen shows on the display.
2. Scroll down to "Confirmation/Adjustment" and press the "ENTER" button.
3. Scroll down to "Climate Control" and press the "ENTER" button.
4. The fan bars will flash on the display during the self-test, and then the fault codes will display in the ambient temperature area.
They will continue scrolling until diagnostic mode is exited.
5. Exit by pressing the "BACK" button on A/C and AV switch assembly until display returns to its normal operation screen.
HVAC system will be OFF.
The self-diagnostic system diagnoses sensors, CAN sys tem, and battery voltage on A/C auto amp. Refer to
applicable sections (items) for details. Fault codes (if any are present) will be displayed in the ambient temper-
ature display area. Refer to HAC-23, "
A/C System Self-Diagnosis Code Chart".
A/C and AV Switch Asse mbly Self-DiagnosisINFOID:0000000001679780
A/C and AV switch assembly self-diagnosis function
The ON/OFF operation (continuity) of each switch in the A/C and AV switch assembly can be checked.
Self-diagnosis mode
AWNIA0098ZZ
AWIIA0081ZZ
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SELF-DIAGNOSIS FUNCTIONHAC-23
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• Press the “BACK” switch and the “UP” switch within 10 seconds after turning the ignition switch from OFF to ACC and hold them for
3 seconds or more. Then the buzzer sounds, all indicators of the
preset switch illuminate, and the self-diagnosis mode starts.
• The continuity of each switch and control dials (A/C and AV switch assembly only) at the ON position can be checked by pressing
each switch and turning each control dial. The buzzer sounds and
LED’s will illuminate if the switch is normal.
Finishing self-diagnosis mode
Self-diagnosis mode is canceled when turning the ignition switch OFF.
A/C System Self-Diagnosis Code ChartINFOID:0000000001679781
SELF-DIAGNOSTIC CODE CHART
AWIIA0171GB
Code No. Reference page
03 Battery voltage out of range CHG-11, "
Inspection Procedure"
30 In-vehicle sensor circuit out of range (low)
HAC-81, "In-Vehicle Sensor Diagnosis Procedure"31 In-vehicle sensor circuit out of range (high)
40 Ambient sensor circuit shortHAC-78, "
Ambient Sensor Diagnosis Procedure"41 Ambient sensor circuit open
50 Optical sensor (Driver) circuit open or shortHAC-84, "
Optical Sensor Diagnosis Procedure"52 Optical sensor (Passenger) circuit open or short
56 Intake sensor circuit shortHAC-86, "
Intake Sensor Diagnosis Procedure"57 Intake sensor circuit open
80 CAN bus faultLAN-14, "
Trouble Diagnosis Flow Chart"
Revision: March 2010 2008 QX56

HAC-24
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MODE DOOR MOTOR
COMPONENT DIAGNOSIS
MODE DOOR MOTOR
System DescriptionINFOID:0000000001679782
SYSTEM DESCRIPTION
Component Parts
Mode door control system components are:
• A/C auto amp.
• A/C and AV switch assembly
• Mode door motor (front)
• PBR (built into mode door motor)
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The mode door position (vent, B/L, foot
, D/F, and defrost) is set by the A/C auto amp. by means of the mode
door motor (front). When a mode door position is selected on the A/C auto amp., voltage is applied to one cir-
cuit of the mode door motor (front) while ground is applied to the other circuit, causing the mode door motor
(front) to rotate. The direction of rotation is determi ned by which circuit has voltage applied to it, and which one
has ground applied to it. The A/C auto amp. monitors the mode door position by measuring the voltage signal
on the PBR circuit.
In AUTO mode the mode door position is set by the A/C auto amp. which determines the proper position
based on inputs from the in-vehicle sensor, ambient sensor , optical sensor, intake sensor, and the temperature
selected by the driver or passenger.
Mode Door Control Specification
COMPONENT DESCRIPTION
Mode Door Motor (Front)
AWIIA0092GB
AWIIA0093GB
Revision: March 2010 2008 QX56

MODE DOOR MOTORHAC-25
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The mode door motor (front) is attached to the heater & cooling unit
assembly. It rotates so that air is discharged from the outlet as indi-
cated by the A/C auto amp. Motor rotation is conveyed to a link
which activates the mode door.
Mode Door Motor (Front) Component Function CheckINFOID:0000000001679783
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - DISCHARGE AIR
1. Press mode switch four times and then press the (DEF) switch. Each position indicator should change shape (on display).
2. Confirm that discharge air comes out accordi ng to the air distribution table. Refer to HAC-15, "
Discharge
Air Flow (Front)".
NOTE:
Confirm that the compressor clutch is engaged (visual inspection) and intake door position is at FRESH
when DEF ( ) or D/F ( ) is selected.
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Can a symptom be duplicated?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK MODE DOOR OPERATION
Check and verify mode door mechanism for smooth operation in each mode.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair as necessary.
5.PERFORM A/C AUTO AMP. SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 6.
6.PERFORM A/C AND AV SWITCH ASSEMBLY SELF-DIAGNOSIS
Perform self-diagnosis to check the A/C and AV switch assembly. Refer to HAC-22, "
A/C and AV Switch
Assembly Self-Diagnosis".
Is the inspection result normal?
YES >> Replace A/C and AV switch assembly. Refer to VTL-7, "Removal and Installation".
NO >> GO TO 7.
WJIA0587E
Revision: March 2010 2008 QX56

HAC-26
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MODE DOOR MOTOR
7.CHECK THE MODE DOOR MO
TOR (FRONT) PBR CIRCUIT
Perform diagnostic procedure for the mode door motor (front). Refer to HAC-25, "
Mode Door Motor (Front)
Component Function Check".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair PBR circuit or replace motor. Refer to HAC-26, "
Mode Door Motor (Front) Diagnosis Pro-
cedure".
8.RECHECK FOR CODES
Perform A/C auto amp. self-diagnosis. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnostic codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 9.
9.RECHECK FOR SYMPTOMS
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Does another symptom exist?
YES >> Repair as necessary.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
Mode Door Motor (Front) Diagnosis ProcedureINFOID:0000000001679784
SYMPTOM:
• Air outlet does not change.
• Mode door motor does not operate normally.
1.CHECK A/C AUTO AMP. FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Press the mode switch to the B/L ( ) mode.
3. Check voltage between A/C auto amp. harness connector M49 terminal 19 and terminal 20 while pressing the mode switch to
the floor ( ) mode.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK MODE DOOR MOTOR CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 19, 20 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 20
19Press
mode
switch Battery
voltage
AWIIA0095ZZ
19 - Ground : Continuity should not exist.
20 - Ground : Continuity should not exist.
AWIIA0096ZZ
Revision: March 2010 2008 QX56

MODE DOOR MOTORHAC-27
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NO >> Repair or replace harness as necessary.
3.CHECK A/C AUTO AMP. FOR GROUND AND POWER
1. Press the mode switch to the D/F ( ) mode.
2. Check voltage between A/C auto amp. harness connector M49 terminal 19 and terminal 20 while pressing the mode switch to
the vent ( ) mode.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
4.CHECK MODE DOOR MOTOR AND CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 19 and terminal 20.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.CHECK MODE DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the mode door motor harness connector.
2. Check continuity between A/C auto amp. harness connector M49 (A) terminal 19, 20 and the mode door motor harness con-
nector M142 (B) terminal 5, 6.
Is the inspection result normal?
YES >> Replace mode door motor. Refer to VTL-24, "Removal
and Installation".
NO >> Repair or replace harness as necessary.
6.CHECK A/C AUTO AMP. FOR PBR POWER AND GROUND
1. Reconnect A/C auto amp. harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 7.
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 19 20 Press
mode
switch Battery
voltage
AWIIA0097ZZ
Continuity should exist.
AWIIA0098ZZ
5 - 19 : Continuity should exist.
6 - 20 : Continuity should exist.
AWIIA0094ZZ
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M49, M50 28 35V
AWIIA0099ZZ
Revision: March 2010 2008 QX56