2009 INFINITI QX56 tow

RSU-14
< REMOVAL AND INSTALLATION >
REAR SUSPENSION MEMBER
 When raising the rear suspension member assembly, use thelocating pins to align the rear suspension member to the vehicle
body.
 When installing the upper and lower rubber seats for the rear coil springs, the arrow embossed on the rubber seats must point out
toward the wheel and tire assembly.
 To connect the rear load leveling air suspension hoses, the lock ring must be fully seated in the fitt ing. Insert the hose “B” into the
lock ring “A” until the lock ring “A” is touching the hose “B” as
shown. Pull on the hose to check that it is securely inserted.
 Perform final tightening of nuts and bolts for the links (rubber bushing) under unladen condition (unladen condition means that the fuel tank, engine coolant and l ubricants are at the full specification, and the spare
tire, jack, hand tools, and mats are in their designated positions) with the tires on level ground.
 Check the wheel alignment. Refer to RSU-6, "Wheel AlignmentInspection"
LEIA0083E
LEIA0076E
LEIA0078E
Revision: December 20092009 QX56

RSU-22
< REMOVAL AND INSTALLATION >
REAR LOWER LINK & COIL SPRING
8. Slowly lower the suitable jack to release the coil spring tension. Then remove the upper rubber seat, coil
spring and lower rubber seat from the rear lower link.
9. Remove the rear lower link adjusting bolt and nut from the rear suspension member using power tool, then remove the rear
lower link.
INSPECTION AFTER REMOVAL
Check the coil spring and rubber seats for deformation, cracks, or other damage and replace if necessary.
INSTALLATION
Installation is in the reverse order of removal.
 Tighten the nuts and bolts to specification. Refer to RSU-21, "Removal and Installation"
.
 When installing the upper and lower rubber seats for the rear coil springs, the arrow embossed on the rubber seats must point out
toward the wheel and tire assembly.
 After installing the rear lower link and coil spring, check the wheel alignment and adjust if necessary. Refer to RSU-6, "Wheel Align-
mentInspection".
LEIA0009E
LEIA0076E
Revision: December 20092009 QX56

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
SEC-101
< ECU DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
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41 Y/B Hood switch Input —Hood closed OFF
0V
Hood open ON Battery voltage
42 GR Oil pressure switch Input — Engine running
Battery voltage
Engine stopped 0V
43 L/Y Wiper auto stop signal Input ON or
START Wiper switch OFF, LO, INT Battery voltage
44 BR Daytime light relay
control Input ONDaytime light system active
0V
Daytime light system inactive Battery voltage
45 G/W Horn relay control Input ON When door locks are operated
using keyfob or Intelligent Key
(OFF
→ ON)* Battery voltage
→ 0V
46 GR Fuel pump relay con-
trol
Input —Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
47 O Throttle control motor
relay control
Input —Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
48 B/R Starter relay (inhibit
switch) InputON or
START Selector lever in "P" or "N"
0V
Selector lever any other posi-
tion Battery voltage
49 R/L Trailer tow relay Output ON Lighting
switch must
be in the 1st
positionOFF
0V
ON Battery voltage
50 W/R Front fog lamp (LH) Output ON or
START Lighting
switch must
be in the 2nd
position
(LOW beam
is ON) and
the front fog
lamp switch OFF
0V
ON Battery voltage
51 W/R Front fog lamp (RH) Output ON or
START Lighting
switch must
be in the 2nd
position
(LOW beam
is ON) and
the front fog
lamp switch OFF
0V
ON Battery voltage
52 L LH low beam head-
lamp Output — Lighting switch in 2nd position Battery voltage
54 R/Y RH low beam head-
lamp Output — Lighting switch in 2nd position Battery voltage
55 G LH high beam head-
lamp Output —Lighting switch in 2nd position
and placed in HIGH or PASS
position Battery voltage
56 L/W RH high beam head-
lamp Output —Lighting switch in 2nd position
and placed in HIGH or PASS
position Battery voltage
57 R/L Parking, license, and
tail lamp
Output ONLighting
swi
t

ch 1st po-
sition OFF
0V
ON Battery voltage
Te r m i n a l
Wire
color Signal name Signal
input/
output Measuring condition
Reference value(Approx.)
Igni-
tion
switch Operation or condition
Revision: December 20092009 QX56

SEC-104
< SYMPTOM DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
INTELLIGENT KEY SYSTEM/ENGIN
E START FUNCTION SYMPTOMS
SYMPTOM DIAGNOSIS
INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION SYMPTOMS
Symptom TableINFOID:0000000003775944
NOTE:
• Before performing the diagnosis in the following table, check “ SEC-3, "
Work Flow"”.
• Check that vehicle is under the condition shown in “Conditions of vehicle” before starting diagnosis, and check each symptom.
• Engine cranking is enabled when the shift lever is in the "Park" position, and in the "Neutral" position only if
the brake pedal is depressed.
• If the following symptoms are detected, check syst ems shown in the “Diagnosis/service procedure” column
in this order.
CONDITIONS OF VEHICLE (OPERATING CONDITIONS)
• Engine start function is ON when setting on CONSULT-III.
• Mechanical key is not inserted in key cylinder.
• One or more of Intelligent Keys with registered Intelligent Key ID is in the vehicle.
Symptom Diagnosis/service procedureReference
page
Ignition switch does not turn on with Intelligent Key.
[LCD displays "KEY DETECTED"] 1. Check steering lock solenoid.
DLK-99
2. Replace Intelligent Key unit.SEC-111
Ignition switch does not turn on with Intelligent Key.
[LCD does not display "PUSH" with arrow toward key
cylinder] 1. Check Intelligent Key unit power supply and ground circuit.
DLK-682. Check ignition knob switch.DLK-116
3. Check key switch (BCM input).DLK-115
4. Check key switch (Intelligent Key unit input).DLK-113
5. Replace Intelligent Key unit.SEC-111
Ignition switch does not turn on with Intelligent Key.
[LCD displays " NO KEY"]1a. Check inside key antenna 1 (rear of center console).
DLK-60
1b. Check inside key antenna 2 (luggage compartment).DLK-62
1c. Check inside key antenna 3 (front of center console).DLK-64
1d. Check inside key antenna 4 (overhead console area).DLK-68
2. Replace Intelligent Key unit.SEC-111
Ignition switch does not turn on with mechanical key1. Check key switch (BCM input).
DLK-1152. Check key switch (Intelligent Key unit input).DLK-113
Engine cannot be cranked with transmission in "Park"
or in "Neutral" position with brake pedal depressed.1. Check transmission signal.
TM-44
2. Check stop lamp switch.EXL-91
Revision: December 20092009 QX56

PRECAUTIONSSR-3
< PRECAUTION >
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5. When the repair work is completed, return the ignition switch to the ″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
Precaution for SRS "AIR BAG" and "SEAT BELT PRE-TENSIONER" Service
INFOID:0000000003775154
• Do not use electrical test equipment to check SRS ci rcuits unless instructed to in this Service Manual.
• Before servicing the SRS, turn ignition switch OFF, disconnect both battery terminals and wait at least 3 min- utes.
For approximately 3 minutes after the terminals are remov ed, it is still possible for the air bags and seat belt
pre-tensioners to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes
have passed.
• The air bag diagnosis sensor unit must always be installed with the arrow mark “ ⇐” pointing toward the front
of the vehicle for proper operation. Also check air bag diagnosis sensor unit for cracks, deformities or rust
before installation and replace as required.
• The spiral cable must be aligned with the neutral position since its rotations are limited. Do not attempt to turn steering wheel or column after removal of steering gear.
• Handle air bag module carefully. Always place driver and front passenger air bag modules with the pad side facing upward and seat mounted front side air bag module standing with the stud bolt side facing down.
• Conduct self-diagnosis to check entire SRS for proper function after replacing any components.
• After air bag inflates, the front instrument panel assembly should be replaced if damaged.
Occupant Classification System PrecautionINFOID:0000000003775155
Replace control unit and passenger front seat cushion as an assembly.
Revision: December 20092009 QX56

SR-8
< ON-VEHICLE REPAIR >
SPIRAL CABLE
5. While pressing tabs, pull lighting and turn signal switch towarddriver door and disconnect from base.
6. Remove the screws, release the clip, and remove the spiral cable.
CAUTION:
• Do not disassemble spiral cable.
• Do not apply lubricant to the spiral cable.
7. Remove the spiral cable connectors. CAUTION:
With the steering linkage di sconnected, the spiral cable
may snap by turning the steer ing wheel beyond the limited
number of turns. The spiral cable can be turned counter-
clockwise about 2.5 turns fr om the neutral position.
8. Remove the steering angle sensor. Refer to BRC-118, "
Removal
and Installation".
INSTALLATION
Installation is in the reverse order of removal.
• Align spiral cable correctly when installing steering wheel. Make
sure that the spiral cable is in the neutral position. The neutral
position is detected by turning left 2.5 revolutions from the right
end position and ending with the knob at the top.
• If equipped with VDC, refer to BRC-8, "
ADJUSTMENT OF STEER-
ING ANGLE SENSOR NEUTRAL POSITION : Special Repair
Requirement" for steering angle sensor adjustment.
• After the work is completed, perform self-diagnosis to make sure no malfunction is detected. Refer to SRC-13, "
SRS Operation
Check".
CAUTION:
LHIA0035E
LHIA0036E
SHIA0193E
WGIA0038E
Revision: December 20092009 QX56

DIAGNOSIS SENSOR UNITSR-17
< ON-VEHICLE REPAIR >
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DIAGNOSIS SENSOR UNIT
Removal and InstallationINFOID:0000000003775164
REMOVAL
CAUTION:
• Before servicing the SRS, turn the ignition switch off, disconnect both battery cables and wait at least 3 minutes.
• Do not use old bolts; replace with new bolts.
• Check diagnosis sensor unit bracket to make sure it is free of deformities, dents, cracks or rust. If it
shows any visible signs of damage, replace with new one.
• Replace diagnosis sensor unit if it has been dropped or sustained an impact.
• When replacing the air bag diagno sis sensor unit, always check with the parts department for he lat-
est parts information. Installing an incorrect air bag diagnosis sensor unit may or may not cause the
air bag warning lamp to illuminate and may cause incorrect deployment of the supplemental air bags
and seat belt pre-tensioner in a collision r esulting in serious personal injury or death.
1. Always check the air bag diagnosis sensor unit E CU discriminated number (identification number) using
CONSULT-III.
2. Disconnect the negative and positive battery term inals, then wait at least three minutes.
3. Disconnect the harness connectors for each air bag module and seat belt pre-tensioner.
4. Remove center console. Refer to IP-20, "
Removal and Installation".
5. Disconnect diagnosis sensor unit harness connectors.
6. Remove bolts from the diagnosis sensor unit.
INSTALLATION
Installation is in the reverse order of removal.
• After the work is completed, perform self-diagnosis to check that no malfunction is detected. Refer to SRC-
13, "SRS Operation Check".
CAUTION:
• After replacing the air bag diagnosis sensor unit, confirm using CO NSULT-III that the ECU discrimi-
nated number (identification number) of the ne w replacement air bag diagnosis sensor unit matches
the ECU discriminated number (identification numb er) of the replaced (old) air bag diagnosis sensor
unit.
• The diagnosis sensor unit must always be installed with the arrow mark " ⇐" pointing toward the
front of the vehicle for proper operation.
NOTE:
1. Diagnosis sensor unit ⇐Vehicle front
AWHIA0159ZZ
Revision: December 20092009 QX56

PRECAUTIONSSRC-93
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005867464
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.
Precaution for SRS "AIR BAG" and "SEAT BELT PRE-TENSIONER" Service
INFOID:0000000003775253
• Do not use electrical test equipment to check SRS ci rcuits unless instructed to in this Service Manual.
• Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 min- utes.
For approximately 3 minutes after the cables are remov ed, it is still possible for the air bag and seat belt pre-
tensioner to deploy. Therefore, do not work on any SR S connectors or wires until at least 3 minutes have
passed.
• The air bag diagnosis sensor unit must always be installed with the arrow mark “ ⇐” pointing toward the front
of the vehicle for proper operation. Also check air bag diagnosis sensor unit for cracks, deformities or rust
before installation and replace as required.
• The spiral cable must be aligned with the neutral position since its rotations are limited. Do not attempt to
turn steering wheel or column after removal of steering gear.
• Handle air bag module carefully. Always place driver and front passenger air bag modules with the pad side facing upward and seat mounted front side air bag module standing with the stud bolt side facing down.
• Conduct self-diagnosis to check entire SRS for proper function after replacing any components.
• After air bag inflates, the front instrument panel assembly should be replaced if damaged.
Occupant Classification System PrecautionINFOID:0000000003775254
Replace occupant classification system control uni t and passenger front seat cushion as an assembly.
Revision: December 20092009 QX56