2008 INFINITI QX56 ignition

DEF-4
< FUNCTION DIAGNOSIS >
REAR WINDOW DEFOGGER SYSTEM
FUNCTION DIAGNOSIS
REAR WINDOW DEFOGGER SYSTEM
System DiagramINFOID:0000000001735602
System DescriptionINFOID:0000000001735603
Operation Description
• Turn rear window defogger switch ON when the ignition switch is turned ON. Then A/C and AV switch
assembly (rear window defogger switch) transmits rear window defogger switch signal to BCM.
• BCM transmits rear window defogger control signal to IPDM E/R and display unit via CAN communication when rear window defogger operates.
• IPDM E/R turns rear window defogger relay and heated mirror relay ON when rear window defogger switch
signal is received.
• Rear window defogger and door mirror defogger are supplied with power and operate when rear window defogger relay and heated mirror relay turn ON.
• Rear window defogger ON is displayed when signal is received.
Timer function
• BCM turns rear window defogger relay and heated mirror relay ON for approximately 15 minutes when rear window defogger switch is turned ON while ignition switch is ON. It makes rear window defogger and door
mirror defogger operate.
• Timer is canceled after pressing rear window defogger switch again during timer operation. Then BCM turns
rear window defogger relay and heated mirror relay OFF. The same reaction also occurs during timer opera-
tion, if the ignition switch is turned OFF.
INPUT/OUTPUT SIGNAL CHART
ALLIA0892GB
Switch Input signal to BCM BCM functionAcutuator
Rear window defogger switch Defogger switch signal Rear window defogger & door mirror
defogger control Rear window defogger
Door mirror defogger
Ignition switch Ignition signal
Revision: March 2010 2008 QX56

DEF-6
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (BCM)
DIAGNOSIS SYSTEM (BCM)
COMMON ITEM
COMMON ITEM : CONSULT-III Function (BCM - COMMON ITEM)INFOID:0000000001735606
APPLICATION ITEM
CONSULT-III performs the following functions via CAN communication with BCM.
SYSTEM APPLICATION
BCM can perform the following functions for each system.
NOTE:
It can perform the diagnosis modes except the following for all subsystem selection items.
REAR WINDOW DEFOGGER
REAR WINDOW DEFOGGER : CONSULT-III Function (BCM - REAR DEFOGGER)
INFOID:0000000001735607
DATA MONITOR
ACTIVE TEST
Diagnosis mode Function Description
WORK SUPPORT Changes the setting for each system function.
SELF-DIAG RESULTS Displays the diagnosis results judged by BCM. Refer to BCS-50, "
DTCIndex".
CAN DIAG SUPPORT MNTR Monitors the reception status of CAN communication viewed from BCM.
DATA MONITOR The BCM input/output signals are displayed.
ACTIVE TEST The signals used to activate each device are forcibly supplied from BCM.
ECU IDENTIFICATION The BCM part number is displayed.
CONFIGURATION This function is not used even though it is displayed.
SystemSub system selection item Diagnosis mode
WORK SUPPORT DATA MONITOR ACTIVE TEST
Rear window defogger REAR DEFOGGER ××
BCM BCM ×
Monitor Item Description
REAR DEF SW Indicates [ON/OFF] condition of rear defogger switch.
IGN SW Indicates [ON/OFF] condition of ignition switch.
Test Item Description
REAR DEFOGGER This test is able to check rear window defogger operation. Rear window defogger operates when
“ON” on CONSULT-I
II screen is touched.
Revision: March 2010 2008 QX56

DEF-8
< COMPONENT DIAGNOSIS >
REAR WINDOW DEFOGGER SWITCH
COMPONENT DIAGNOSIS
REAR WINDOW DEFOGGER SWITCH
DescriptionINFOID:0000000001735609
• The rear window defogger is operated by turning the rear window defogger switch ON.
• Turns the indicator lamp in the rear window defogger switch ON when operating the rear window defogger.
Component Function CheckINFOID:0000000001735610
1. CHECK REAR WINDOW DEFOGGER SWITCH FUNCTION
Check that the indicator lamp of rear window defogger illuminates with rear window defogger switch ON.
Is the inspection result normal?
YES >> Rear window defogger switch function is OK.
NO >> Refer to DEF-8, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735611
1. CHECK A/C AND AV SWITCH ASSEMBLY (REAR WINDOW DEFOGGER SWITCH) CIRCUIT
Does rear window defogger switch operate normally?
Is the inspection result normal?
YES >> Inspection End.
NO >> GO TO 2
2. CHECK HARNESS CONTINUITY
1. Turn ignition switch OFF.
2. Disconnect BCM and A/C and AV switch assembly.
3. Check continuity between BCM connector (A) and A/C and AV switch assembly connector (B).
4. Check continuity between BCM connector (A) and ground.
Is the inspection result normal?
YES >> Replace A/C and AV switch assembly. Refer to VTL-7, "Removal and Installation".
NO >> Repair or replace harness.
BCM connector Terminal A/C and AV switch
assembly connector Terminal Continuity
M18 (A) 9 M98 (B)16Yes
BCM connector Terminal
GroundContinuity
M18 (A) 9 No
ALLIA0315ZZ
Revision: March 2010 2008 QX56

REAR WINDOW DEFOGGER RELAYDEF-9
< COMPONENT DIAGNOSIS >
C
DE
F
G H
I
J
K
M A
B
DEF
N
O P
REAR WINDOW DEFOGGER RELAY
DescriptionINFOID:0000000001735612
Power is supplied to the rear window defogger with BCM control.
Component Function CheckINFOID:0000000001735613
1. CHECK REAR WINDOW DEFOGGER RELAY POWER SUPPLY CIRCUIT
Check that an operation noise of rear window defogger re lay (located in IPDM E/R) can be heard when turning
the rear window defogger switch ON.
Is the inspection result normal?
YES >> Rear window defogger relay power supply circuit is OK.
NO >> Refer to DEF-9, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735614
1.CHECK FUSES
Check if any of the following fuses in the IPDM E/R are blown.
Is the inspection result normal?
YES >> GO TO 2
NO >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.
2. CHECK REAR WINDOW DEFOGGER RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between IPDM E/R connector and ground.
Is the inspection result normal?
YES >> Replace IPDM E/R. Refer to PCS-34, "Removal and Installation of IPDM E/R".
NO >> GO TO 3
3. CHECK INTERMITTENT INCIDENT
Check intermittent incident.
Refer to GI-38, "
Intermittent Incident"
Is the inspection result normal?
YES >> Check the following.
• Battery power supply circuit.
• IPDM E/R.
NO >> Repair or replace the malfunctioning parts.
COMPONENT PARTS AMPEREFUSE NO.
IPDM E/R 15A46
IPDM E/R 15A47
Te r m i n a l s
Condition of rear
window defogger
switch Voltage (V)
(Approx.)
(+)
(–)
IPDM E/R con-
nector Te r m i n a l
E124 60 Ground ON Battery voltage
OFF 0
LIIA2190E
Revision: March 2010 2008 QX56

DEF-10
< COMPONENT DIAGNOSIS >
REAR WINDOW DEFOGGER POWER SUPPLY AND GROUND CIRCUIT
REAR WINDOW DEFOGGER POWER SUPPLY AND GROUND CIRCUIT
DescriptionINFOID:0000000001735615
Heats the heating wire with the power supply from the rear window defogger relay to prevent the rear window
from fogging up.
Component Function CheckINFOID:0000000001735616
1. CHECK REAR WINDOW DEFOGGER
Check that the heating wire of rear window defogger is heated when turning the rear window defogger switch
ON.
Is the inspection result normal?
YES >> Rear window defogger is OK.
NO >> Refer to DEF-10, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735617
1. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between rear window defogger connector and ground.
Is the inspection result normal?
YES >> GO TO 2
NO >> GO TO 3
2. CHECK GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear window defogger.
3. Check continuity between rear window defogger connector and ground.
Is the inspection result normal?
YES >> GO TO 4
NO >> Repair or replace harness.
3. CHECK HARNESS CONTINUITY
Te r m i n a l s Condition of rear window
defogger switch Voltage (V)
(Approx.)
(+)
(–)
Rear window
defogger
connector Te r m i n a l
D406 1 Ground ON Battery voltage
OFF 0
ALLIA0177ZZ
Rear window defogger connector Terminal
GroundContinuity
D604 2 Yes
ALLIA0178ZZ
Revision: March 2010 2008 QX56

DEF-12
< COMPONENT DIAGNOSIS >
DOOR MIRROR DEFOGGER LH
DOOR MIRROR DEFOGGER LH
DescriptionINFOID:0000000001735623
Heats the heating wire with the power supply from the rear window defogger relay to prevent the door mirror
from fogging up.
Component Function CheckINFOID:0000000001735624
1. CHECK DOOR MIRROR DEFOGGER LH
Check that heating wire of door mirror defogger LH is heated when turning the rear window defogger switch
ON.
Is the inspection result normal?
YES >> Door mirror defogger is OK.
NO >> Refer to DEF-12, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735625
1. CHECK POWER SUPPLY
Check if the following fuse in the IPDM E/R is blown.
Is the inspection result normal?
YES >> GO TO 2
NO >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.
2. CHECK DOOR MIRROR DE FOGGER POWER SUPPLY CIRCUIT
Check voltage between IPDM E/R connector and ground.
Is the inspection result normal?
YES >> GO TO 3
NO >> Replace IPDM E/R. Refer to PCS-34, "
Removal and Installation of IPDM E/R".
3. CHECK DOOR MIRROR DEFOGGER POWER SUPPLY CIRCUIT 2
1. Turn ignition switch OFF.
2. Disconnect door mirror LH.
3. Turn ignition switch ON.
4. Check voltage between door mirror LH connector and ground.
Is the inspection result normal?
YES >> GO TO 4
COMPONENT PARTS AMPEREFUSE NO.
IPDM E/R 15A43
ConnectorTe r m i n a l
ConditionVoltage (V)
(Approx.)
(+) (-)
E120 23 Ground Rear window defogger
switch ON
Battery voltage
Rear window defogger
switch OFF 0
LIIA2049E
ConnectorTe r m i n a l
ConditionVoltage (V)
(Approx.)
(+) (-)
D4 10 Ground Rear window defogger
switch ON
Battery voltage
Rear window defogger
switch OFF 0
LIIA1456E
Revision: March 2010
2008 QX56

DOOR MIRROR DEFOGGER LHDEF-13
< COMPONENT DIAGNOSIS >
C
DE
F
G H
I
J
K
M A
B
DEF
N
O P
NO >> Repair or replace harness.
4. CHECK DOOR MIRROR DEFOGGER CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R and door mirror LH.
3. Check continuity between IPDM E/R connector E120 terminal 23 and door mirror LH connector D4 terminal 10.
Is the inspection result normal?
YES >> GO TO 5
NO >> Repair or replace harness.
5. CHECK DOOR MIRROR DEFOGGER GROUND CIRCUIT
Check continuity between door mirror LH connector D4 terminal 11
and ground.
Is the inspection result normal?
YES >> GO TO 6
NO >> Repair or replace harness.
6. CHECK DOOR MIRROR DEFOGGER LH
Check door mirror defogger LH.
Refer to DEF-13, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 7
NO >> Replace door mirror. Refer to MIR-11, "
Door Mirror Assembly".
7. CHECK INTERMITTENT INCIDENT
Check intermittent incident.
Refer to GI-38, "
Intermittent Incident".
Is the inspection result normal?
YES >> Check the following. • Battery power supply circuit.
• IPDM E/R.
NO >> Repair or replace the malfunctioning parts.
Component InspectionINFOID:0000000001735626
1. CHECK DOOR MIRROR DEFOGGER
Check continuity between door mirror LH terminals 10 and 11.
Is the inspection result normal?
YES >> Check the condition of the harness and the connector.
NO >> Replace malfunctioning door mirror LH. Refer to MIR-
11 , "Door Mirror Assembly".
23 - 10
: Continuity should exist.
WIIA0529E
11 - Ground: Continuity should exist.
LIIA1454E
10 - 11 : Continuity should exist.
WIIA0531E
Revision: March 2010 2008 QX56

DEF-14
< COMPONENT DIAGNOSIS >
DOOR MIRROR DEFOGGER RH
DOOR MIRROR DEFOGGER RH
DescriptionINFOID:0000000001735631
Heats the heating wire with the power supply from the rear window defogger relay to prevent the door mirror
from fogging up.
Component Function CheckINFOID:0000000001735632
1.CHECK DOOR MIRROR DEFOGGER RH
Check that the heating wire of door mirror defogger RH is heated when turning the rear window defogger
switch ON.
Is the inspection result normal?
YES >> Door mirror defogger RH is OK.
NO >> Refer to DEF-14, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001735633
1. CHECK POWER SUPPLY
Check if the following fuse in the IPDM E/R is blown.
Is the inspection result normal?
YES >> GO TO 2
NO >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.
2. CHECK DOOR MIRROR DE FOGGER POWER SUPPLY CIRCUIT
Check voltage between IPDM E/R connector and ground.
Is the inspection result normal?
YES >> GO TO 3
NO >> Replace IPDM E/R. Refer to PCS-34, "
Removal and Installation of IPDM E/R".
3. CHECK DOOR MIRROR DEFOGGER POWER SUPPLY CIRCUIT 2
1. Turn ignition switch OFF.
2. Disconnect door mirror RH.
3. Turn ignition switch ON.
4. Check voltage between door mirror RH connector and ground.
Is the inspection result normal?
YES >> GO TO 4
COMPONENT PARTS AMPEREFUSE NO.
IPDM E/R 15A43
ConnectorTe r m i n a l
ConditionVoltage (V)
(Approx.)
(+) (-)
E120 23 Ground Rear window defogger
switch ON
Battery voltage
Rear window defogger
switch OFF 0
LIIA2049E
ConnectorTe r m i n a l
ConditionVoltage (V)
(Approx.)
(+) (-)
D107 10 Ground Rear window defogger
switch ON
Battery voltage
Rear window defogger
switch OFF 0
LIIA1456E
Revision: March 2010
2008 QX56