2010 INFINITI QX56 engine control module

MWI
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
MWI-89
< ECU DIAGNOSIS >
C
D E
F
G H
I
J
K L
M B A
O P
If No CAN Communication Is Available With BCM
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 voltage 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 malfunction when the ignition switch is turned OFF.
NOTE:
The tail lamp turns OFF when the ignition switch is turned ON.
FRONT WIPER CONTROL
IPDM E/R detects front wiper stop posit ion by a front wiper auto stop signal.
When a front wiper auto stop signal is in the conditions listed below, IPDM E/R stops power supply to wiper
after repeating a front wiper 10 second activation and 20 second stop five times.
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.
Control part Fail-safe in operation
Cooling fan • Turns ON the cooling fan relay when the ignition switch is turned ON
• Turns OFF the cooling fan relay when the ignition switch is turned OFF
Control part
Fail-safe in 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 LH/RH relays OFF
•Parking lamps
• License plate lamps
• Tail lamps • 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 • 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 control is activated while the front wipe r is set in the INT mode and the front wiper
motor is operating.
Rear window defogger Rear window defogger relay OFF
A/C compressor A/C relay OFF
Front fog lamps Front fog lamp relay OFF
Ignition switch Ignition relayTail lamp relay
ON ON —
OFF OFF —
Ignition switchFront wiper switch Auto stop signal
ON OFF
Front wiper stop position signal cannot be
input 10 seconds.
ON The signal does not change for 10 seconds.
Revision: April 20092010 QX56

MWI-98
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005384300
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 severity 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 inopera tive, 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 unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified 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 Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c 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 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000005276727
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: April 20092010 QX56

PB-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005239316
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 severity 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 inopera tive, 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 unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified 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 Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c 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 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000005239317
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: April 20092010 QX56

PCS
PCS-1
ELECTRICAL & POWER CONTROL
C
DE
F
G H
I
J
K L
B
SECTION PCS
A
O P
N
CONTENTS
POWER CONTROL SYSTEM
IPDM E/R
BASIC INSPECTION ....... .............................
2
DIAGNOSIS AND REPAIR WORKFLOW ..... .....2
Work Flow ........................................................... ......2
FUNCTION DIAGNOSIS ...............................5
RELAY CONTROL SYSTEM ......................... .....5
System Diagram .................................................. ......5
System Description ...................................................6
Component Parts Location ........................................7
POWER CONTROL SYSTEM .............................8
System Diagram .................................................. ......8
System Description ...................................................8
SIGNAL BUFFER SYSTEM ................................9
System Diagram .................................................. ......9
System Description ...................................................9
POWER CONSUMPTION CONTROL SYS-
TEM ....................................................................
10
System Diagram .................................................. ....10
System Description .................................................10
Component Parts Location ......................................11
DIAGNOSIS SYSTEM (IPDM E/R) .....................12
Diagnosis Description ......................................... ....12
CONSULT - III Function (IPDM E/R) .......................14
COMPONENT DIAGNOSIS .........................17
U1000 CAN COMM CIRCUIT ...........................17
Description ........................................................... ....17
DTC Logic ................................................................17
Diagnosis Procedure ...............................................17
POWER SUPPLY AND GROUND CIRCUIT ....18
Diagnosis Procedure ...............................................18
ECU DIAGNOSIS .........................................19
IPDM E/R (INTELLIGENT POWER DISTRI-
BUTION MODULE ENGINE ROOM) ................
19
Reference Value .................................................. ....19
Terminal Layout .......................................................21
Physical Values ................................................... ....22
Wiring Diagram ........................................................27
Fail Safe ..................................................................30
DTC Index ...............................................................32
PRECAUTION ..............................................33
PRECAUTIONS .................................................33
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ....
33
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ...................................
33
REMOVAL AND INSTALLATION ...............35
IPDM E/R (INTELLIGENT POWER DISTRI-
BUTION MODULE ENGINE ROOM) ................
35
Removal and Installation of IPDM E/R ................ ....35
Revision: April 20092010 QX56

PCS
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
PCS-23
< ECU DIAGNOSIS > [IPDM E/R]
C
D
E
F
G H
I
J
K L
B A
O P
N
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
1 B/Y Battery power supply Input OFF —Battery voltage
2 R Battery power supply Input OFF —Battery voltage
3BRECM relay Output— Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
4W/LECM relay Output— Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
6L Throttle control motor
relay Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
7 W/B ECM relay control Input — Ignition switch ON or START
0V
Ignition switch OFF or ACC Battery voltage
8 R/B Fuse 54 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
10 G Fuse 45
(Canada only) Output ONDaytime light system active
0V
Daytime light system inactive Battery voltage
11 Y/B A/C compressor Output ON or
START A/C switch ON or defrost A/C
switch
Battery voltage
A/C switch OFF or defrost A/C
switch 0V
12 L/W Ignition switch sup-
plied power Input —OFF or ACC
0V
ON or START Battery voltage
13 B/Y Fuel pump relay Output — Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
14 Y/R Fuse 49 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
15 LG/B Fuse 50 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
16 G Fuse 51 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
17 W Fuse 55 Output —Ignition switch ON or START
Battery voltage
Ignition switch OFF or ACC 0V
19 W/R Starter motor Output START—Battery voltage
21 BR Ignition switch sup-
plied power
Input —OFF or ACC
0V
START Battery voltage
22 G Battery power supply Output OFF —Battery voltage
23 GR/W Door mirror defogger
output signal Output —When rear defogger switch is
ON
Battery voltage
When raker defogger switch is
OFF 0V
24 L Cooling fan relay Output — Conditions correct for cooling
fan operation
Battery voltage
Conditions not correct for
cooling fan operation 0V
Revision: April 20092010 QX56

PCS
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
PCS-25
< ECU DIAGNOSIS > [IPDM E/R]
C
D
E
F
G H
I
J
K L
B A
O P
N
43 L/Y Wiper auto stop signal Input
ON or
START Wiper switch OFF, LO, INT Battery voltage
44 BR Daytime light relay
control
(Canada only) 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 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) Input
ON or
START Selector lever in "P" or "N"
0V
Selector lever any other posi-
tion Battery voltage
49 R/L Trailer tow relay
(With trailer tow)
Illumination
(Without trailer tow) Output ONLighting
switch must
be in the 1st
position OFF
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 Y
(With
DTRL)
L/W
(Without DTRL) RH high beam head-
lamp
Output —Lighting switch in 2nd position
and placed in HIGH or PASS
position
Battery voltage
57 R/LPa

rking, license, and
tail lamp Output ONLighting
switch 1st po-
sition OFF
0V
ON Battery voltage
59 B Ground Input ——0V
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: April 20092010 QX56

PCS-30
< ECU DIAGNOSIS >[IPDM E/R]
IPDM E/R (INTELLIGENT POWER DI
STRIBUTION MODULE ENGINE ROOM)
Fail Safe
INFOID:0000000005146516
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
ABMIA1043GB
Revision: April 20092010 QX56

PCS
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
PCS-31
< ECU DIAGNOSIS > [IPDM E/R]
C
D
E
F
G H
I
J
K L
B A
O P
N
If No CAN Communication Is Available With BCM
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 voltage 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 malfunction when the ignition switch is turned OFF.
NOTE:
The tail lamp turns OFF when the ignition switch is turned ON.
FRONT WIPER CONTROL
IPDM E/R detects front wiper stop posit ion by a front wiper auto stop signal.
When a front wiper auto stop signal is in the conditions listed below, IPDM E/R stops power supply to wiper
after repeating a front wiper 10 second activation and 20 second stop five times.
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.
Control part Fail-safe in operation
Cooling fan • Turns ON the cooling fan relay when the ignition switch is turned ON
• Turns OFF the cooling fan relay when the ignition switch is turned OFF
Control part
Fail-safe in 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 LH/RH relays OFF
•Parking lamps
• License plate lamps
• Tail lamps • 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 • 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 control is activated while the front wipe r is set in the INT mode and the front wiper
motor is operating.
Rear window defogger Rear window defogger relay OFF
A/C compressor A/C relay OFF
Front fog lamps Front fog lamp relay OFF
Ignition switch Ignition relayTail lamp relay
ON ON —
OFF OFF —
Ignition switchFront wiper switch Auto stop signal
ON OFF
Front wiper stop position signal cannot be
input 10 seconds.
ON The signal does not change for 10 seconds.
Revision: April 20092010 QX56