2011 INFINITI QX56 engine

PCS-16
< ECU DIAGNOSIS INFORMATION >[IPDM E/R]
IPDM E/R
ST/INHI RLYIgnition switch ON Off
At engine cranking INHI ON
→ ST ON
The status of starter relay or starter control relay cannot be recognized by
the battery voltage malfunction, etc. when the starter relay is ON and the
starter control relay is OFF. UNKWN
DETENT SW Ignition switch ON  Pull the selector lever with selec-
tor lever in P position.
 Selector lever in any position oth-
er than P. Off
Release the selector lever with selector lever in P position. On
S/L RLY -REQ None of the conditions below are present. Off
 Open the driver door after the ignition switch is turned OFF (for a few
seconds).
 Press the push-button ignition switch when the steering lock is activat-
ed. On
S/L STATE Steering lock is locked. LOCK
Steering lock is unlocked. UNLK
[DTC: B210A] is detected. UNKWN
OIL P SW Ignition switch OFF or ACC
Open
Ignition switch ON (engine running)
Ignition switch ON (engine stopped) Close
HOOD SW Close the hood Off
Open the hood On
HL WASHER REQ Not operating Off
Headlamp washer operating On
THFT HRN REQ Not operation Off
 Panic alarm is activated
 Theft warning alarm is activated
On
HORN CHIRP Not operation Off
Door locking with Intelligent Key (horn chirp mode) On
Monitor Item Condition Value/Status
Revision: 2010 May2011 QX56

PCS
IPDM E/RPCS-17
< ECU DIAGNOSIS INFORMATION > [IPDM E/R]
C
D
E
F
G H
I
J
K L
B A
O P
N
TERMINAL LAYOUT
PHYSICAL VALUES
JPMIA1423ZZ
Te r m i n a l N O .
(Wire color) Description
Condition Va l u e
(Approx.)
Signal name Input/
Output
+–
1
(W) Ground Battery power supply Input Ignition switch OFF Battery voltage
2
(G) Ground Battery power supply Input Ignition switch OFF Battery voltage
3
(R) Ground Starter motor Output Ignition switch ON 0 V
At engine cranking Battery voltage
4
(L) Ground Battery power supply Input Ignition switch OFF Battery voltage
5
(P/L) Ground
Ignition relay power
supply OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
7
(W/G) Ground
Ignition relay power
supply OutputIgnition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
8
(W) Ground Battery power supply Input Ignition switch OFF Battery voltage
9
(B) Ground Ground — Ignition switch ON 0 V
14
(L) Ground Rear window defogger Output
Ignition switch
ONRear window defogger
switch OFF
0 V
Rear window defogger
switch ON Battery voltage
Revision: 2010 May2011 QX56

PCS-18
< ECU DIAGNOSIS INFORMATION >[IPDM E/R]
IPDM E/R
17
(B) Ground Cooling fan motor
ground
Output Ignition switch ON 0 V
18
(B) Ground Ground — Ignition switch ON 0 V
19
(V) Ground Front fog lamp (RH) Output Lighting
switch 2ND or
AUTO (Light
is illuminated)Front fog lamp switch
OFF
0 V
Front fog lamp switch ON Battery voltage
20
(W) Ground Front fog lamp (LH) Output Lighting
switch 2ND or
AUTO (Light
is illuminated)Front fog lamp switch
OFF
0 V
Front fog lamp switch ON Battery voltage
21
(L) Ground
Headlamp washer re-
lay control Output
Ignition switch
ON Headlamp washer acti-
vated
0 V
Headlamp washer deacti-
vated 12 V
23
(GR/R) Ground Cranking request Output Select lever P or N (Ignition switch ON) 0 V
Select lever in any position other than P or
N (Ignition switch ON)
12 V
Engine running 12 V
24
(W/G) Ground Oil pressure switch Input Ignition switch
ONEngine stopped 0 V
Engine running 12 V
25
(L/Y) Ground Front wiper stop posi-
tion InputIgnition switch
ON Front wiper stop position 0 V
Any position other than
front wiper stop position
12 V
26
(P) Ground CAN-L Input/
Output ——
27
(L) Ground CAN-H
Input/
Output ——
30
(R/W) Ground Starter relay control Output  Ignition switch OFF or ACC
 At engine cranking
0 V
 Ignition switch ON
 Engine running 12 V
31
(B) Ground Injector relay control Output  Approximately 1 second after turning
the ignition switch ON
 Engine running 0 - 1.5 V
Approximately 1 second or more after turn-
ing the ignition switch ON Battery voltage
32
(LG) Ground Hood switch Input Close the hood 12 V
Open the hood 0 V
33
(R) Ground Alternator control Output Ignition switch OFF or ACC 0 V
Ignition switch ON 6 V
34
(P/B) Ground Horn relay control Output The horn is deactivated Battery voltage
The horn is activated 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-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
IPDM E/RPCS-21
< ECU DIAGNOSIS INFORMATION > [IPDM E/R]
C
D
E
F
G H
I
J
K L
B A
O P
N
Fail-SafeINFOID:0000000006220173
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
66
(SB) Ground
Push-button ignition
switch InputPress the push-button ignition switch 0 V
Release the push-button ignition switch 12 V
68
(O) Ground Ignition relay monitor Input Ignition switch OFF or ACC 12 V
Ignition switch ON 0 V
69
(W/B) Ground Ignition power supply Output Ignition switch OFF or ACC 0 V
Ignition switch ON Battery voltage
72
(Y/R) Ground Cooling fan control Output Ignition switch
OFF 5 V
ACC 0 V
ON
2. 5 V
Engine running
Te r m i n a l N O .
(Wire color) Description
Condition Va l u e
(Approx.)
Signal name Input/
Output
+–
JMMIA0404GB
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%
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
 Side marker 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
Revision: 2010 May2011 QX56

PCS
PRECAUTIONSPCS-33
< PRECAUTION > [POWER DISTRIBUTION SYSTEM]
C
D
E
F
G H
I
J
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

PCS
SYSTEMPCS-37
< SYSTEM DESCRIPTION > [POWER DISTRIBUTION SYSTEM]
C
D
E
F
G H
I
J
K L
B A
O P
N
SYSTEM
POWER DISTRIBUTION SYSTEM
POWER DISTRIBUTION SYSTEM : System DiagramINFOID:0000000006220196
POWER DISTRIBUTION SYST
EM : System DescriptionINFOID:0000000006220197
SYSTEM DESCRIPTION
 PDS (POWER DISTRIBUTION SYSTEM) is the system that BCM controls with the operation of the push-
button ignition switch and performs the power distributi on to each power circuit. This system is used instead
of the mechanical power supply changing mechanism wit h the operation of the conventional key cylinder.
 The push-button ignition switch can be operated when Intelligent Key is in the following condition. Refer to Engine Start Function for details.
- Intelligent Key is in the detection area of the inside key antenna.
- Intelligent Key backside is contact ed to push-button ignition switch.
 The push-button ignition switch operation is input to BCM as a signal. BCM changes the power supply posi-
tion according to the status and operates the follo wing relays to supply power to each power circuit.
- Ignition relay (inside IPDM E/R)
- Ignition relay-1
- ACC relay
- Blower relay
NOTE:
The engine switch operation changes due to the conditions of brake pedal, selector lever and vehicle speed.
 The power supply position can be confirmed with the light ing of the indicators near the push-button ignition
switch.
BATTERY SAVER SYSTEM
When all the following conditions are met for 60 minutes, the battery saver system will cut off the power supply
to prevent battery discharge.
 The ignition switch is in the ACC position
 All doors are closed
 Selector lever is in the P position
Reset Condition of Battery Saver System
In order to prevent the battery from discharging, the battery saver system will cut off the power supply when all
doors are closed, the selector lever is on P position and t he ignition switch is left on ACC position for 1 hour. If
any of the following conditions are met the battery saver system is released and the steering will change auto-
matically to lock position from OFF position.
 Opening any door
 Operating with door request switch on door lock
 Operating with Intelligent Key on door lock
Press push-button ignition switch and ignition swit ch will change to ACC position from OFF position.
JMMIA0444GB
Revision: 2010 May2011 QX56

PCS-38
< SYSTEM DESCRIPTION >[POWER DISTRIBUTION SYSTEM]
SYSTEM
STEERING LOCK OPERATION
Steering is locked by steering lock unit when ignition switch
is in the OFF position, selector lever is in the P
position and any of the following conditions are met.
 Opening door
 Closing door
 Door is locked with door request switch
 Door is locked with Intelligent Key
POWER SUPPLY POSITION CHANGE TABLE BY PUSH-BUTTON IGNITION SWITCH OPERA-
TION
The power supply position changing operation can be performed with the following operations.
NOTE:
 When an Intelligent Key is within the detection area of inside key antenna and when Intelligent Key backside
is contacted to push-button ignition switch, it is equivalent to the operations below.
 When starting the engine, the BCM monitors under the engine start conditions,
- Brake pedal operating condition
- Selector lever position
- Vehicle speed
Vehicle speed: less than 4 km/h (2.5 MPH)
Vehicle speed: 4 km/h (2.5 MPH) or more
Emergency stop operation
 Press and hold the push-button ignition switch for 2 seconds or more.
 Press the push-button ignition switch 3 times or more within 1.5 seconds. Power supply position
Engine start/stop condition
Push-button ignition switch
operation frequency
Selector lever position Brake pedal operation condition
LOCK → ACC — Not depressed 1
LOCK → ACC → ON — Not depressed 2
LOCK → ACC → ON →
OFF — Not depressed 3
LOCK → START
ACC → START
ON → START P or N position Depressed 1
Engine is running → OFF — — 1
Power supply position Engine start/stop condition
Push-button ignition switch
operation frequency
Selector lever position Brake pedal operation condition
Engine is running → ACC — — Emergency stop operation
Engine stall return operation
while driving N position Not depressed 1
Revision: 2010 May2011 QX56