2011 INFINITI QX56 power steering

PRECAUTIONSMIR-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006257245
The Supplemental Restraint System such as “A IR 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g 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 “SRS AIR BAG”.
 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 Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric 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 Necessary for Steering Wh eel Rotation after Battery Disconnect
INFOID:0000000006257246
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the batte ry disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wil l remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56

PCS-2
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect ..................................
33
SYSTEM DESCRIPTION ............................35
COMPONENT PARTS .................................... ...35
Component Parts Location .................................. ...35
Component Description .........................................35
BCM ........................................................................35
Ignition Relay ..........................................................35
Accessory Relay .....................................................36
Blower Relay ..........................................................36
Push-Button Ignition Switch ....................................36
SYSTEM .......................................................... ...37
POWER DISTRIBUTION SYST EM ........................ ...37
POWER DISTRIBUTION SYSTEM : System Dia-
gram .................................................................... ...
37
POWER DISTRIBUTION SYSTEM : System De-
scription ..................................................................
37
DIAGNOSIS SYSTEM (BCM) ............................39
COMMON ITEM ..................................................... ...39
COMMON ITEM : CONSULT-III Function (BCM -
COMMON ITEM) ................................................. ...
39
INTELLIGENT KEY ................................................ ...40
INTELLIGENT KEY : CONSULT-III Function
(BCM - INTELLIGENT KEY) ...................................
40
ECU DIAGNOSIS INFO RMATION ..............45
BCM ................................................................ ...45
List of ECU Reference ......................................... ...45
WIRING DIAGRAM .....................................46
POWER DISTRIBUTION SYSTEM ................ ...46
Wiring Diagram .................................................... ...46
BASIC INSPECTION ...................................53
DIAGNOSIS AND REPAIR WORK FLOW ..... ...53
Work Flow ............................................................ ...53
DTC/CIRCUIT DIAGNOSIS ...................... ...56
B2614 ACC RELAY CIRCUIT ........................ ...56
DTC Logic ............................................................ ...56
Diagnosis Procedure ..............................................56
Component Inspection ............................................57
B2615 BLOWER RELAY CIRCUIT ...................59
DTC Logic ............................................................ ...59
Diagnosis Procedure ..............................................59
Component Inspection ......................................... ...60
B2616 IGNITION RELAY CIRCUIT ...................61
DTC Logic ............................................................ ...61
Diagnosis Procedure ...............................................61
Component Inspection ............................................62
B2618 BCM .......................................................63
DTC Logic ............................................................ ...63
Diagnosis Procedure ...............................................63
B261A PUSH-BUTTON IGNITION SWITCH .....64
DTC Logic ............................................................ ...64
Diagnosis Procedure ...............................................64
B26F1 IGNITION RELAY ..................................66
DTC Logic ............................................................ ...66
Diagnosis Procedure ...............................................66
B26F2 IGNITION RELAY ..................................68
DTC Logic ............................................................ ...68
Diagnosis Procedure ...............................................68
B26F6 BCM .......................................................70
DTC Logic ............................................................ ...70
Diagnosis Procedure ...............................................70
PUSH-BUTTON IGNITION SWITCH .................71
Component Function Check ............................... ...71
Diagnosis Procedure ...............................................71
Component Inspection ............................................72
PUSH-BUTTON IGNITION SWITCH POSI-
TION INDICATOR ..............................................
74
Description ........................................................... ...74
Component Function Check ..................................74
Diagnosis Procedure ...............................................74
SYMPTOM DIAGNOSIS ............................76
PUSH-BUTTON IGNITION SWITCH DOES
NOT OPERATE .............................................. ...
76
Description ........................................................... ...76
Diagnosis Procedure ...............................................76
PUSH-BUTTON IGNITION SWITCH POSI-
TION INDICATOR DOES NOT ILLUMINATE ...
77
Description ..............................................................77
Diagnosis Procedure ...............................................77
REMOVAL AND INSTALLATION ..............78
PUSH-BUTTON IGNITION SWITCH .............. ...78
Exploded View ..................................................... ...78
Removal and Installation .........................................78
Revision: 2010 May2011 QX56

PCS-6
< SYSTEM DESCRIPTION >[IPDM E/R]
SYSTEM
NOTE:
BCM controls the starter relay.
RELAY CONTROL SYSTEM : Fail-SafeINFOID:0000000006220163
CAN COMMUNICATION CONTROL
When CAN communication with ECM and BCM is impossible,
IPDM E/R performs fail-safe control. After CAN
communication recovers normally, it also returns to normal control.
If No CAN Communication Is Available With ECM
If No CAN Communication Is Available With BCM
Control relay Input/output Transmi t unit Control part Reference page
 Headlamp low relay
 Headlamp high relay  Low beam request signal
 High beam request signal
BCM (CAN)
 Headlamp (LO)
 Headlamp (HI) EXL-10
Front fog lamp relay Front fog light request signal BCM (CAN) Front fog lamp
EXL-20
Tail lamp relay Position light request signal BCM (CAN) Parking lamp
 License plate
lamp
Tail lamp
 Side marker lamp EXL-18
Illuminations
INL-6
 Front wiper relay
 Front wiper high relayFront wiper request signal BCM (CAN)
Front wiper motorWW-7Front wiper stop position sig-
nal Front wiper motor
Rear window defogger
relay Rear window defogger control
signal
BCM (CAN)
Rear window defog-
ger
DEF-6
Horn relay
 Theft warning horn
relay  Theft warning horn request
signal
 Horn reminder signal BCM (CAN)
Horn (high)
Horn (low) SEC-17
 Starter relayNOTE
 Starter control relayStarter control rela
y signal BCM (CAN)
Starter motorSEC-10
,
SEC-10Steering lock unit condition
signal Steering lock unit
Starter relay control signal TCM
Steering lock relay Steering lock relay signal BCM (CAN)
Steering lock unitSEC-10
Steering lock unit condition
signal Steering lock unit
A/T shift selector (detention
switch) signal A/T shift selector
(detention switch)
A/C relay A/C compressor request sig-
nal ECM (CAN)
A/C compressor
(Magnet clutch) HAC-17
Headlamp washer relay
Headlamp washer request
signal BCM (CAN)Headlamp washer
pump WW-13
 Ignition relay
 Ignition relay-2
 Ignition relay-3Ignition switch ON signal BCM (CAN)
Each control unit,
sensor, actuator and
relay (ignition power
supply)PCS-29Vehicle speed signal
Combination meter
(CAN)
Push-button ignition switch
signal Push-button ignition
switch
Control part Fail-safe operation
Cooling fan  Transmits the pulse duty signal (PWM signal) 100% when the ignition switch is turned ON.
 Transmits the pulse duty signal (PWM signal) 0% when the ignition switch is turned OFF.
A/C compressor A/C relay OFF
Alternator Transmits the power generation command signal (PWM signal) 0%
Revision: 2010 May2011 QX56

PCS
SYSTEMPCS-7
< SYSTEM DESCRIPTION > [IPDM E/R]
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IGNITION RELAY MALFUNCTION DETECTION FUNCTION
 IPDM E/R monitors the voltage at the contact circuit and
excitation coil circuit of the ignition relay inside it.
 IPDM E/R judges the ignition relay error if the volt age differs between the contact circuit and the excitation
coil circuit.
 If the ignition relay cannot turn OFF due to contact seizure, it activates the tail lamp relay for 10 minutes to alert the user to the ignition relay malfunc tion when the ignition switch is turned OFF.
FRONT WIPER PROTECTION FUNCTION
IPDM E/R detects front wiper stop position by a front wiper stop position signal.
When a front wiper stop position signal is in the conditi ons listed below, IPDM E/R stops power supply to wiper
after repeating a front wiper 10 seconds activation and 20 seconds stop.
NOTE:
This operation status can be confirmed on the IPDM E/ R “Data Monitor” that displays “BLOCK” for the item
“WIP PROT” while the wiper is stopped.
STARTER MOTOR PROTECTION FUNCTION
IPDM E/R turns OFF the starter control relay to protect the starter motor when the starter control relay remains
active for 90 seconds.
POWER CONTROL SYSTEM
Control part Fail-safe operation
Headlamp  Turns ON the headlamp low relay when the ignition switch is turned ON
 Turns OFF the headlamp low relay when the ignition switch is turned OFF
 Headlamp high relay OFF
Parking lamp
 License plate lamp
 Illumination
 Tail lamp  Turns ON the tail lamp relay when the ignition switch is turned ON
 Turns OFF the tail lamp relay when the ignition switch is turned OFF
Front wiper motor  The status just before activation of fail-safe control is maintained until the ignition switch is
turned OFF while the front wiper is operating at LO or HI speed.
 The wiper is operated at LO speed until the ignition switch is turned OFF if the fail-safe con- trol is activated while the front wiper is set in the INT mode and the front wiper motor is op-
erating.
 Return automatically wiper to stop position when ignition switch is turned ON if fail-safe con- trol is activated while front wiper motor is operated and wiper stops in the other position than
stop position.
Front fog lamp Front fog lamp relay OFF
Horn Horn OFF
Ignition relay The status just before activation of fail-safe is maintained.
Starter motor Starter control relay OFF
Steering lock unit Steering lock relay OFF
Voltage judgment IPDM E/R judgment Operation
Ignition relay contact side Ignition relay excitation coil
side
ON ON Ignition relay ON normal —
OFF OFF Ignition relay OFF normal —
ON OFF Ignition relay ON stuck  Detects DTC “B2098: IGN RELAY ON”
 Turns ON the tail lamp relay for 10 min-
utes
OFF ON Ignition relay OFF stuck Detects DTC “B2099: IGN RELAY OFF”
Ignition switch Front wiper switch Front wiper stop position signal
ON OFF
The front wiper stop position signal (stop position) cannot be input for
10 seconds.
ON The front wiper stop position signal does not change for 10 seconds.
Revision: 2010 May2011 QX56

PCS
IPDM E/RPCS-19
< ECU DIAGNOSIS INFORMATION > [IPDM E/R]
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35
(W) Ground ECM relay power sup-
ply OutputIgnition switch OFF
(More than a few seconds after turning ig-
nition switch OFF)
0 V
 Ignition switch ON
 Ignition switch OFF (For a few seconds after turning ignition
switch OFF) Battery voltage
36
(V) Ground ECM relay power sup-
ply
OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
37
(L) Ground Parking lamp (RH) Output Ignition switch
ONLighting switch OFF 0 V
Lighting switch 1ST Battery voltage
38
(Y) Ground Tail lamp (RH) Output Ignition switch
ONLighting switch OFF 0 V
Lighting switch 1ST Battery voltage
39
(L/B) Ground Front wiper HI Output Ignition switch
ONFront wiper switch OFF 0 V
Front wiper switch LO 9 V
Front wiper switch HI Battery voltage
41
(L/G) Ground ECM relay control Output Ignition switch OFF
(More than a few seconds after turning ig-
nition switch OFF)
Battery voltage
 Ignition switch ON
 Ignition switch OFF (For a few seconds after turning ignition
switch OFF) 0 - 1.5 V
42
(L) Ground Battery power supply Output Ignition switch OFF
(More than a few seconds after turning ig-
nition switch OFF)
0 V
 Ignition switch ON
 Ignition switch OFF (For a few seconds after turning ignition
switch OFF) Battery voltage
43
(LG) Ground Parking lamp (LH) Output
Ignition switch
ONLighting switch OFF 0 V
Lighting switch 1ST Battery voltage
44
(L/W) Ground Tail lamp (LH), license
plate lamp
OutputIgnition switch
ON Lighting switch OFF 0 V
Lighting switch 1ST Battery voltage
45
(Y/R) Ground Front wiper LO Output Ignition switch
ONFront wiper switch OFF 0 V
Front wiper switch LO Battery voltage
46
(L/W) Ground
Steering lock unit pow-
er supply OutputIgnition switch ACC or ON 0 V
Ignition switch
OFF
A few seconds after
opening the driver door
Battery voltage
Ignition switch
LOCK Press the push-button ig-
nition switch
Battery voltage
48
(BR) Ground P/N position Input Select lever in any position other than P or
N (Ignition switch ON)
0 V
Select lever P or N (Ignition switch ON) 12 V
49
(R) Ground Headlamp HI (RH) Output Lighting
switch 2ND or
AUTO (Light
is illuminated)Lighting switch other than
HI and PASS
0 V
 Lighting switch HI
 Lighting switch PASS Battery voltage
Te r m i n a l N O .
(Wire color) Description
Condition Va l u e
(Approx.)
Signal name Input/
Output
+–
Revision: 2010 May2011 QX56

PCS-20
< ECU DIAGNOSIS INFORMATION >[IPDM E/R]
IPDM E/R
50
(LG/B) Ground Headlamp HI (LH) Output Lighting
switch 2ND or
AUTO (Light
is illuminated)Lighting switch other than
H and PASS
0 V
 Lighting switch HI
 Lighting switch PASS Battery voltage
51
(BR/Y) Ground Headlamp LO (LH) Output Lighting switch OFF 0 V
Lighting switch 2ND or AUTO (light is illu-
minated)
Battery voltage
52
(W) Ground Headlamp LO (RH) Output Lighting switch OFF 0 V
Lighting switch 2ND or AUTO (light is illu-
minated)
Battery voltage
54
(SB) Ground ECM power supply Output Approximately 1 second or more than after
turning the ignition switch ON
0 V
 Approximately 1 second after turning the ignition switch ON
 Engine running Battery voltage
55
(O) Ground Throttle control motor
relay power supply
OutputIgnition switch OFF
(More than a few seconds after turning ig-
nition switch OFF)
0 V
 Ignition switch ON
 Ignition switch OFF (For a few seconds after turning ignition
switch OFF) Battery voltage
56
(L) Ground A/C compressor power
supply OutputEngine run-
ning A/C switch OFF 0 V
A/C switch ON
(A/C compressor is oper-
ating)
Battery voltage
57
(V) Ground Ignition relay power
supply
OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
58
(BR/R) Ground Ignition relay power
supply
OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
59
(W/B) Ground Ignition relay power
supply
OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
60
(V/R) Ground
Throttle control motor
relay control OutputIgnition switch ON
→ OFF 0 - 1.0 V
↓
Battery voltage
↓
0 V
Ignition switch ON 0 - 1.0 V
61
(W) Ground Ignition relay power
supply
OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
62
(SB) Ground Ignition relay power
supply
OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
63
(P) Ground Steering lock unit con-
dition-2
InputSteering lock is unlocked 0 V
Steering lock is locked 12 V
64
(G/Y) Ground A/T shift selector
(detention switch) InputIgnition switch
ON Select lever P 0 V
Select lever in any posi-
tion other than P
12 V
65
(L) Ground
Steering lock unit con-
dition-1 InputSteering lock is unlocked 12 V
Steering lock is locked 0 V
Te r m i n a l N O .
(Wire color) Description
Condition Va l u e
(Approx.)
Signal name Input/
Output
+–
Revision: 2010 May2011 QX56

PCS-22
< ECU DIAGNOSIS INFORMATION >[IPDM E/R]
IPDM E/R
IGNITION RELAY MALFUNCTION DETECTION FUNCTION
 IPDM E/R monitors the voltage at the contact circuit and
excitation coil circuit of the ignition relay inside it.
 IPDM E/R judges the ignition relay error if the volt age differs between the contact circuit and the excitation
coil circuit.
 If the ignition relay cannot turn OFF due to contact seiz ure, it activates the tail lamp relay for 10 minutes to
alert the user to the ignition relay malfunction when the ignition switch is turned OFF.
FRONT WIPER PROTECTION FUNCTION
IPDM E/R detects front wiper stop positi on by a front wiper stop position signal.
When a front wiper stop position signal is in the conditi ons listed below, IPDM E/R stops power supply to wiper
after repeating a front wiper 10 seconds activation and 20 seconds stop.
NOTE:
This operation status can be confirmed on the IPDM E/ R “Data Monitor” that displays “BLOCK” for the item
“WIP PROT” while the wiper is stopped.
STARTER MOTOR PROTECTION FUNCTION
IPDM E/R turns OFF the starter control relay to protect the starter motor when the starter control relay remains
active for 90 seconds.
DTC IndexINFOID:0000000006220174
NOTE:
 The details of time display are as follows.
- CRNT: A malfunction is detected now.
- PAST: A malfunction was detected in the past.
 IGN counter is displayed on FFD (Freeze Frame data).
- The number is 0 when is detected now.
- The number increases like 1 → 2 ··· 38 → 39 after returning to the normal condition whenever IGN OFF →
ON.
- The number is fixed to 39 until the self-diagnosis results are erased if it is over 39.
× : Applicable
Ignition relay The status just before activation of fail-safe is maintained.
Starter motor Starter control relay OFF
Steering lock unit Steering lock relay OFF Control part Fail-safe operation
Voltage judgment
IPDM E/R judgment Operation
Ignition relay contact side Ignition relay excitation coil
side
ON ON Ignition re lay ON normal —
OFF OFF Ignition relay OFF normal —
ON OFF Ignition relay ON stuck  Detects DTC “B2098: IGN RELAY ON”
 Turns ON the tail lamp relay for 10 min-
utes
OFF ON Ignition relay OFF stuck Detects DTC “B2099: IGN RELAY OFF”
Ignition switch Front wiper switch Front wiper stop position signal
ON OFF
The front wiper stop position signal (stop position) cannot be input for
10 seconds.
ON The front wiper stop position signal does not change for 10 seconds.
CONSULT display Fail-safe Refer to
No DTC is detected.
further testing
may be required. ——
U1000: CAN COMM CIRCUIT ×PCS-28
B2098: IGN RELAY ON ×PCS-29
Revision: 2010 May2011 QX56

PCS
PRECAUTIONSPCS-33
< PRECAUTION > [POWER DISTRIBUTION SYSTEM]
C
D
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G H
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K L
B A
O P
N
PRECAUTION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006220187
The Supplemental Restraint System such as “A IR 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
 To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g 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 “SRS AIR BAG”.
 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 Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric 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 Necessary for Steering Wh eel Rotation after Battery Disconnect
INFOID:0000000006220188
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the batte ry disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wil l remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56