4WD INFINITI QX56 2008 Factory Service Manual

QUICK REFERENCE CHART: QX56
2008
Unit: mm (in)
*: Always check with the Parts Department for the latest parts information.
Front Wheel Alignment (Unladen*1)INFOID:0000000006237759
*1: Fuel, radiator coolant and engine oil full. Spare tire, jack, hand tools and mats in designated positions.
*2: Target value 37° 31 ′ (37.52 °)
*3: Target value 33 ° 59 ′ (33.98 °)
*4: Target value 37 ° 44 ′ (37.73 °)
*5: Target value 33 ° 29 ′ (33.48 °)
*6: Some vehicles may be equipped with straight (non-adjustable) lower link bolts and washers. In order to adjust camber and ca ster on
these vehicles, first replace the lower link bolts and washers with adjustable (cam) bolts and washers. Make
NGK
Model Standard model
Standard type* DILFR5A-11
Gap (Nominal) 1.1 (0.043)
Drive type2WD 4WD
Camber *6
Degree minute (decimal degree) Minimum -0
° 51 ′ (-0.85 °)-0 ° 33 ′ (-0.55 °)
Nominal -0 ° 6 ′ (-0.10 °)0 ° 12 ′ (0.20 °)
Maximum 0 ° 39 ′ (0.65 °)0 ° 57 ′ (0.95 °)
Cross camber 0 ° 45 ′ (0.75 °) or less 0 ° 45 ′ (0.75 °) or less
Caster *6
Degree minute (decimal degree) Minimum 3
° 15 ′ (3.25 °)2 °45 ′ (2.75 °)
Nominal 4 ° 0 ′ (4.00 °)3 ° 30 ′ (3.50 °)
Maximum 4 ° 45 ′ (4.75 °)4 ° 15 ′ (4.25 °)
Cross caster 0 ° 45 ′
(0.75 °) or less 0 ° 45 ′ (0.75 °) or less
Kingpin inclination
Degree minute (decimal degree) 13
° 32 ′ (13.53 °)13 °13 ′ (13.22 °)
Total toe-in Distance (A
− B) Minimum 1.8 mm (0.07 in) 1.8 mm (0.07 in)
Nominal 2.8 mm (0.11 in) 2.8 mm (0.11 in)
Maximum 3.8 mm (0.15 in) 3.8 mm (0.15 in)
Angle (left side or right side)
Degree minute (decimal degree) Minimum 0
° 3 ′ (0.05 °)0 ° 3 ′ (0.05 °)
Nominal 0 ° 5 ′ (0.08 °)0 ° 5 ′ (0.08 °)
Maximum 0 ° 7 ′ (0.12 °)0 ° 7 ′ (0.12 °)
Wheel turning angle
(full turn) Inside
Degree minute (decimal degree)
34
° 31 ′ – 38 ° 31 ′ *2
(34.52 ° – 38.52 °) 34
° 44 ′ – 38 ° 44 ′ *4
(34.73 ° – 38.73
° )
Outside
Degree minute (decimal degree) 30
° 59 ′ – 34 ° 59 ′ *3
(30.98 ° – 34.98 °) 30
° 29 ′ – 34 ° 29 ′ *5
(30.48 ° – 34.48 °)
SFA234AC

2008
QUICK REFERENCE CHART: QX56
Rear Wheel Alignment
INFOID:0000000006237757
Wheelarch Height (Unladen*1)INFOID:0000000006237758
Unit: mm (in)
*1: Fuel, radiator coolant and engine oil full. Spare tire, jack, hand tools and mats in designated positions.
*2: Verify the vehicle height. If vehicle height is not within ± 10 mm (0.39 in) of the specification, perform the control unit initialization pro-
cedure. Camber
Degree minute (decimal degree)
Minimum 0
° 0 ′ (0 °)
Nominal - 0 ° 30 ′ (-0.5 °)
Maximum - 1 ° 0 ′ (-1.0 °)
Cross camber 0 ° 45 ′ (0.75 °)
To e - i n Distance (A - B)
Minimum 0 mm (0 in)
Nominal 3.3 mm (0.130 in)
Maximum 6.6 mm (0.260 in)
Cross toe 2 mm (0.079 in)
Angle (left, right)
Degree minute (decimal degree) Minimum 0
° 0 ′ (0 °)
Nominal 0 ° 7 ′ (0.11 °)
Maximum 0 ° 14 ′ (0.22 °)
Cross toe 0 ° 8 ′ (0.14 °)
SFA234AC
Suspension type
Air leveling*2
Applied model 2WD 4WD
Front wheelarch height (Hf)920
(36.22) 937
(36.89)
Rear wheelarch height (Hr) 917
(36.10) 937
(36.89)
LEIA0085E

BRC-26
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
CV1
(ON/OFF) ––× Front side switch-over solenoid
valve (cut valve) (ON/OFF) status is
displayed.
CV2
(ON/OFF) ––× Rear side switch-over solenoid
valve (cut-valve) (O
N/OFF) status is
displayed.
SV1
(ON/OFF) ––× Front side switch-over solenoid
valve (suction valve) (ON/OFF) sta-
tus is displayed.
SV2
(ON/OFF) ––× Rear side switch-over solenoid
valve (suction valve) (ON/OFF) sta-
tus is displayed.
VDC FAIL SIG
(ON/OFF) ––× VDC fail signal (ON/OFF) status is
displayed.
TCS FAIL SIG
(ON/OFF) ––× TCS fail signal (ON/OFF) status is
displayed.
ABS FAIL SIG
(ON/OFF) ––×
ABS fail signal (ON/OFF) status is
displayed.
EBD FAIL SIG
(ON/OFF) ––× EBD fail signal (ON/OFF) status is
displayed.
FLUID LEV SW
(ON/OFF) ×
– ×Brake fluid level switch (ON/OFF)
status is displayed.
EBD SIGNAL
(ON/OFF) ––×
EBD operation (ON/OFF) status is
displayed.
ABS SIGNAL
(ON/OFF) ––× ABS operation (ON/OFF) status is
displayed.
TCS SIGNAL
(ON/OFF) ––× TCS operation (ON/OFF) status is
displayed.
VDC SIGNAL
(ON/OFF) ––×
VDC operation (ON/OFF) status is
displayed.
EBD WARN LAMP –– ×Brake warning lamp (ON/OFF) sta-
tus is displayed.
SLCT LVR POSI ××× Shift position judged by transmis-
sion range switch signal.
R POSI SIG ––×Shift position judged by transmis-
sion range switch signal.
2WD/4WD ––×It recognizes on software whether it
is 2WD and whether it is in 4WD
state.
BST OPER SIG ––×Active booster operation (ON/OFF)
st
atus is
di

splayed.
PRESS SENSOR ×– ×Brake pressure detected by pres-
sure sensor is displayed.
CRANKING SIG ––×The input state of the key SW
START position signal is displayed.
PRESS SEN 2 ––×Brake pressure detected by pres-
sure sensor is displayed.
DELTA S SEN ––×The amount of stroke sensor move-
ments in the active booster detected
by DELTA S SEN is displayed.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
Revision: March 2010 2008 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-89
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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RR RH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive
(in fail-safe mode) ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
RR LH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive
(in fail-safe mode) ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
RR LH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive
(in fail-safe mode) ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
MOTOR RELAY Motor and motor relay operation When the motor relay and motor are op-
erating
ON
When the motor relay and motor are not
operating OFF
ACTUATOR RLY Actuator relay operation When the actuator relay is operating
ON
When the actuator relay is not operating OFF
ABS WARN LAMP ABS warning lamp
(Note 3) When ABS warning lamp is ON
ON
When ABS warning lamp is OFF OFF
OFF LAMP VDC OFF indicator lamp
(Note 3) When VDC OFF indicator lamp is ON
ON
When VDC OFF indicator lamp is OFF OFF
SLIP LAMP SLIP indicator lamp
(Note 3) When SLIP indicator lamp is ON
ON
When SLIP indicator lamp is OFF OFF
4WD FAIL REQ
(Note 2) Transfer control unit fail-safe signal When transfer control unit is in fail-safe
mode
ON
When transfer control unit is normal OFF
BST OPER SIG Active booster operation Active booster is active
ON
Active booster is inactive OFF
EBD SIGNAL EBD operation EBD is active
ON
EBD is inactive OFF
ABS SIGNAL ABS operation ABS is active
ON
ABS is inactive OFF
TCS SIGNAL TCS operation TCS is active
ON
TCS is inactive OFF
VDC SIGNAL VDC operation VDC is active
ON
VDC is inactive OFF
EBD FAIL SIG EBD fail-safe signal In EBD fail-safe
ON
EBD is normal OFF
ABS FAIL SIG ABS fail-safe signal In ABS fail-safe
ON
ABS is normal OFF
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: March 2010 2008 QX56

BRC-90
< ECU DIAGNOSIS >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
TCS FAIL SIG TCS fail-safe signalIn TCS fail-safe ON
TCS is normal
OFF
VDC FAIL SIG VDC fail-safe signal In VDC fail-safe
ON
VDC is normal OFF
CRANKING SIG Crank operation Crank is active
ON
Crank is inactive OFF
CV1 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
CV2 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
SV1 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
SV2 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
DECEL G-SEN Longitudinal acceleration detected by Decel
G-Sensor Vehicle stopped
Approx. 0 G
Vehicle running -1.7 to 1.7 G
EBD WARN LAMP EBD warning lamp
(Note 3) When EBD warning lamp is ON
ON
When EBD warning lamp is OFF OFF
N POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = N position
ON
A/T shift position = other than N position OFF
P POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = P position
ON
A/T shift position = other than P position OFF
R POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = R position
ON
A/T shift position = other than R position OFF
2WD/4WD Drive axle 2WD model
2WD
4WD model 4WD
PRESS SEN2 Brake fluid pressure detected by rear pres-
sure sensor With ignition switch turned ON and brake
pedal released
Approx. 0 bar
With ignition switch turned ON and brake
pedal depressed –40 to 300 bar
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: March 2010 2008 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-91
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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BRC
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NOTE:
• 1: Confirm tire pr essure is normal.
• 2: Only 4WD models.
• 3: On and off timing for warning lamp and indicator lamp.
- ABS warning lamp: Refer to BRC-83, "
Description".
- Brake warning lamp: Refer to BRC-84, "
Description".
- VDC OFF indicator lamp: Refer to BRC-85, "
Description".
- SLIP indicator lamp: Refer to BRC-86, "
Description".
TERMINAL LAYOUT
DELTA S SEN Value detected by delta stroke sensor When brake pedal is depressed 1.05 - 1.80 mm
When brake pedal is released
0.00 mm (+0.6/-0.4)
RELEASE SWITCH
NO Active booster signal status When brake pedal is depressed
ON
When brake pedal is released OFF
RELEASE SWITCH
NC Active booster signal status When brake pedal is depressed
OFF
When brake pedal is released ON
STP OFF RLY Stop lamp relay signal When stop lamp relay is ON
ON
When stop lamp relay is OFF OFF
PRES CTRL ACC This item is not used for this model. ——
PRES FAIL ACC This item is not used for this model. ——
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
AWFIA0032ZZ
Revision: March 2010 2008 QX56

DLN-1
TRANSMISSION & DRIVELINE
CEF
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SECTION DLN
A
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DLN
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CONTENTS
DRIVELINE
ATX14B
BASIC INSPECTION ....... .............................
6
DIAGNOSIS AND REPAIR WORKFLOW ..... .....6
Work Flow ........................................................... ......6
Preliminary Check .....................................................7
FUNCTION DIAGNOSIS ..............................10
4WD SYSTEM ................................................ ....10
System Diagram .................................................. ....10
System Description .................................................11
Component Parts Location ......................................16
CAN Communication ...............................................17
DIAGNOSIS SYSTEM (TRANSFER CON-
TROL UNIT) ........................................................
18
CONSULT-III Function (ALL MODE AWD/4WD) ....18
COMPONENT DIAGNOSIS .........................22
P1811 POWER SUPPLY CIRCUIT FOR
TRANSFER CONTROL UNIT ........................ ....
22
Description .......................................................... ....22
DTC Logic ...............................................................22
Diagnosis Procedure ...............................................22
Component Inspection ............................................23
P1802 – P1804, P1809 TRANSFER CON-
TROL UNIT .........................................................
24
Description ..............................................................24
DTC Logic ...............................................................24
Diagnosis Procedure ...............................................24
P1807 VEHICLE SPEED SENSOR (A/T) ..........26
Description .......................................................... ....26
DTC Logic ...............................................................26
Diagnosis Procedure ...............................................26
P1808 VEHICLE SPEED SENSOR (ABS) .........27
Description .......................................................... ....27
DTC Logic ............................................................ ....27
Diagnosis Procedure ...............................................27
P1810 NEUTRAL-4LO SWITCH .......................28
Description ...............................................................28
DTC Logic ................................................................28
Diagnosis Procedure ...............................................28
Component Inspection .............................................30
P1813 4WD SHIFT SWITCH .............................31
Description ...............................................................31
DTC Logic ................................................................31
Diagnosis Procedure ...............................................31
Component Inspection .............................................33
P1814 WAIT DETECTION SWITCH .................35
Description ...............................................................35
DTC Logic ................................................................35
Diagnosis Procedure ...............................................35
Component Inspection .............................................37
P1816 PNP SWITCH .........................................38
Description ...............................................................38
DTC Logic ................................................................38
Diagnosis Procedure ...............................................38
P1817 ACTUATOR MOTOR .............................39
Description ...............................................................39
DTC Logic ................................................................39
Diagnosis Procedure ...............................................39
Component Inspection .............................................43
P1818 ACTUATOR POSITION SWITCH ..........45
Description ...............................................................45
DTC Logic ................................................................45
Diagnosis Procedure ...............................................45
Component Inspection .............................................47
P1819 TRANSFER CONTROL DEVICE ...........48
Description ...............................................................48
DTC Logic ................................................................48
Diagnosis Procedure ...........................................
....48
Revision: March 2010 2008 QX56

DLN-2
P1820 ENGINE SPEED SIGNAL ......................52
Description ........................................................... ...52
DTC Logic ...............................................................52
Diagnosis Procedure ..............................................52
P1822 CLUTCH PRESSURE SOLENOID .........53
Description ..............................................................53
DTC Logic ...............................................................53
Diagnosis Procedure ..............................................53
Component Inspection ............................................55
P1823 2-4 SOLENOID .......................................57
Description ........................................................... ...57
DTC Logic ...............................................................57
Diagnosis Procedure ..............................................57
Component Inspection ............................................60
P1824 TRANSFER MOTOR ..............................61
Description ..............................................................61
DTC Logic ...............................................................61
Diagnosis Procedure ..............................................61
Component Inspection ............................................65
P1826 TRANSFER FLUID TEMPERATURE ....67
Description ........................................................... ...67
DTC Logic ...............................................................67
Diagnosis Procedure ..............................................67
Component Inspection ............................................68
P1827 CLUTCH PRESSURE SWITCH .............70
Description ........................................................... ...70
DTC Logic ...............................................................70
Diagnosis Procedure ..............................................70
Component Inspection ............................................71
P1828 LINE PRESSURE SWITCH ....................73
Description ........................................................... ...73
DTC Logic ...............................................................73
Diagnosis Procedure ..............................................73
Component Inspection ............................................75
P1829 THROTTLE POSITION SIGNAL (ECM)
...
76
Description ........................................................... ...76
DTC Logic ...............................................................76
Diagnosis Procedure ..............................................76
P1830 ABS OPERATION SIGNAL (ABS) ........77
Description ........................................................... ...77
DTC Logic ...............................................................77
Diagnosis Procedure ..............................................77
P1831 VDC OPERATION SIGNAL (ABS) ........78
Description ........................................................... ...78
DTC Logic ...............................................................78
Diagnosis Procedure ..............................................78
P1832 TCS OPERATION SIGNAL (ABS) .........79
Description ........................................................... ...79
DTC Logic ...............................................................79
Diagnosis Procedure ..............................................79
ECU DIAGNOSIS .......................................80
TRANSFER CONTROL UNIT ...........................80
Reference Value .................................................. ...80
Wiring Diagram .......................................................88
DTC Index ...............................................................95
SYMPTOM DIAGNOSIS ...........................100
4WD SYSTEM SYMPTOMS ........................... ..100
Symptom Table .................................................... .100
4WD SHIFT INDICATOR LAMP AND 4LO IN-
DICATOR LAMP DO NOT TURN ON ..............
101
Description ............................................................101
Diagnosis Procedure .............................................101
4WD WARNING LAMP DOES NOT TURN ON ..103
Description ........................................................... .103
Diagnosis Procedure .............................................103
4WD SHIFT INDICATOR LAMP OR 4LO INDI-
CATOR LAMP DO NOT CHANGE ...................
105
Description ........................................................... .105
Diagnosis Procedure .............................................105
ATP WARNING LAMP DOES NOT TURN ON ..107
Description ........................................................... .107
Diagnosis Procedure .............................................107
4WD SHIFT INDICATOR LAMP KEEPS
FLASHING ........................................................
109
Description ........................................................... .109
Diagnosis Procedure .............................................109
4WD WARNING LAMP FLASHES RAPIDLY ..110
Description ............................................................110
Diagnosis Procedure .............................................110
4WD WARNING LAMP FLASHES SLOWLY ..111
Description ............................................................111
Diagnosis Procedure .............................................111
HEAVY TIGHT-CORNER BRAKING SYMP-
TOM OCCURS ................................................ ..
112
Description ........................................................... .112
Diagnosis Procedure .............................................112
ATP SWITCH ....................................................114
Description ........................................................... .114
Diagnosis Procedure .............................................114
4WD SYSTEM DOES NOT OPERATE ............116
Description ........................................................... .116
Diagnosis Procedure .............................................116
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ...........................
117
NVH Troubleshooting Chart ..................................117
PRECAUTION ............... ............................118
Revision: March 2010 2008 QX56

DLN-6
< BASIC INSPECTION >[ATX14B]
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Work FlowINFOID:0000000001737094
WORK FLOW
DETAILED FLOW
1.CUSTOMER INFORMATION
Interview the customer to obtain detailed information about the symptom.
>> GO TO 2
2.PRELIMINARY CHECK
Perform preliminary check. Refer to DLN-7, "
Preliminary Check".
>> GO TO 3
3.SELF-DIAGNOSIS
Perform self-diagnosis. Refer to DLN-18, "
CONSULT-III Function (ALL MODE AWD/4WD)".
AWNIA1592GB
Revision: March 2010 2008 QX56

DIAGNOSIS AND REPAIR WORKFLOWDLN-7
< BASIC INSPECTION > [ATX14B]
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>> GO TO 4
4.SYMPTOM
Check for symptoms. Refer to DLN-100, "
Symptom Table".
>> GO TO 5
5.MALFUNCTIONING PARTS
Repair or replace the applicable parts.
>> GO TO 6
6.SYSTEM OPERATION
Check system operation.
>> GO TO 7
7.SELF-DIAGNOSIS
Perform self-diagnosis.
Are any DTC's displayed?
YES >> GO TO 5
NO >> Inspection End
Preliminary CheckINFOID:0000000001737095
TRANSFER FLUID CHECK
Check for leaks and fluid level. Refer to DLN-127, "Inspection".
PREPARATION FOR ROAD TEST
The purpose of the test is to determine overall performance of trans-
fer case and analyze causes of malfunctions.
When a malfunction is found in any part of transfer, perform the road
test to locate the malfunction area and repair the malfunction parts.
The road test consists of the following three parts.
1. CHECK BEFORE ENGINE IS STARTED
2. CHECK AT IDLE
3. CRUISE TEST
CHECK BEFORE ENGINE IS STARTED
1.CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface.
2. Turn ignition switch to OFF position.
3. Move A/T selector lever to P position.
4. Set 4WD shift switch to 2WD position.
5. Turn ignition switch to ON position. (Do not start engine.)
Does 4WD shift indicator lamp turn ON for approximately 1 second?
YES >> GO TO 2.
NO >> GO TO DLN-101, "
Diagnosis Procedure".
2.CHECK 4WD WARNING LAMP
1. Turn ignition switch to OFF position.
2. Move A/T selector lever to P position.
3. Set 4WD shift switch to 2WD position.
4. Turn ignition switch to ON position. (Do not start engine.)
SMT089D
Revision: March 2010 2008 QX56