2010 INFINITI QX56 engine control module

P1574 ASCD VEHICLE SPEED SENSOREC-351
< COMPONENT DIAGNOSIS > [VK56DE]
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P1574 ASCD VEHICLE SPEED SENSOR
Component DescriptionINFOID:0000000005149413
The ECM receives two vehicle speed sensor signals via
CAN communication line. One is sent from combina-
tion meter and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD
control. Refer to EC-33, "
System Description" for ASCD functions.
On Board Diagnosis LogicINFOID:0000000005149414
• This self-diagnosis has the one trip detection logic.
• The MIL will not light up for this self-diagnosis.
NOTE:
• If DTC P1574 is displayed with DTC UXXXX, first perform the tr ouble diagnosis for DTC UXXXX.
• If DTC P1574 is displayed with DT C P0500, first perform the trouble diagnosis for DTC P0500. Refer
to EC-275, "
On Board Diagnosis Logic".
• If DTC P1574 is displayed with DT C P0605, first perform the trouble diagnosis for DTC P0605. Refer
to EC-286, "
On Board Diagnosis Logic".
• If DTC P1574 is displayed with DT C P0607, first perform the trouble diagnosis for DTC P0607. Refer
to EC-288, "
On Board Diagnosis Logic".
DTC Confirmation ProcedureINFOID:0000000005149415
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Step 3 may be conducted with the dr ive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
1. Start engine (VDC switch OFF).
2. Drive the vehicle at more than 40 km/h (25 MPH).
3. Check DTC.
4. If DTC is detected, go to EC-351, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149416
1.CHECK DTC WITH TCM
Check DTC with TCM. Refer to TM-30, "
OBD-II Diagnostic Trouble Code (DTC)".
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2.CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-23, "
CONSULT-III Function (ABS)".
DTC No. Trouble Diagnosis
Name DTC Detecting Condit
ion Possible Cause
P1574
1574 ASCD vehicle speed
sensor ECM detects a difference between two vehicle
speed signals is out of the specified range. • Harness or connectors
(The CAN communication line is open or
shorted.)
• Combination meter
• ABS actuator and electric unit (control unit)
• Wheel sensor
•TCM
•ECM
Revision: April 20092010 QX56

EC-482
< PRECAUTION >[VK56DE]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005149502
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 SRS 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 SRS 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.
On Board Diagnosis (OBD) S ystem of Engine and A/TINFOID:0000000005149503
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
• Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any repair
or inspection work. The open/short circuit of re lated switches, sensors, solenoid valves, etc. will
cause the MIL to light up.
• Be sure to connect and lock the connectors secure ly after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
• Certain systems and components, especially those related to OBD, may use a new style slide-lock-
ing type harness connector. For descrip tion and how to disconnect, refer to PG-64
.
• Be sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MIL to li ght up due to the short circuit.
• Be sure to connect rubber tubes properly afte r work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.
• Be sure to erase the unnecessary malfunction info rmation (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionINFOID:0000000005149504
•Always use a 12 volt battery as power source.
• Do not attempt to disconnect battery cables while engine is
running.
• Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.
• Before removing parts, turn ig nition switch OFF and then dis-
connect negative battery cable.
SEF289H
Revision: April 20092010 QX56

PRECAUTIONSEM-3
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005259661
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 Necessary for Steering Wheel Rotation After Battery Disconnect
INFOID:0000000005260133
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 disconnecti ng 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 power 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

EX-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005260138
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:0000000005260139
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

EXL-1
DRIVER CONTROLS
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CONTENTS
EXTERIOR LIGHTING SYSTEM
BASIC INSPECTION ....... .............................4
DIAGNOSIS AND REPAIR WORKFLOW ..... .....4
Work Flow ........................................................... ......4
FUNCTION DIAGNOSIS ...............................7
HEADLAMP .................................................... .....7
System Diagram .................................................. ......7
System Description ...................................................7
Component Parts Location ........................................7
Component Description .............................................7
DAYTIME LIGHT SYSTEM .................................9
System Diagram .................................................. ......9
System Description ...................................................9
Component Parts Location ........................................9
Component Description ...........................................10
AUTO LIGHT SYSTEM ......................................11
System Diagram ......................................................11
System Description .................................................11
Component Parts Location ......................................12
Component Description ...........................................12
HEADLAMP AIMING SYSTEM (MANUAL) .......13
System Diagram .................................................. ....13
System Description .................................................13
Component Parts Location ......................................13
Component Description ...........................................13
FRONT FOG LAMP ............................................14
System Diagram .................................................. ....14
System Description .................................................14
Component Parts Location ......................................14
Component Description ...........................................14
TURN SIGNAL AND HAZARD WARNING
LAMPS ...............................................................
15
System Diagram .................................................. ....15
System Description .................................................15
Component Parts Location ......................................15
Component Description ....................................... ....16
PARKING, LICENSE PLATE AND TAIL
LAMPS ..............................................................
17
System Diagram ......................................................17
System Description ..................................................17
Component Parts Location ......................................17
Component Description ...........................................18
DIAGNOSIS SYSTEM (BCM) ...........................19
HEADLAMP ........................................................... ....19
HEADLAMP : CONSULT-III Function (BCM -
HEAD LAMP) ...........................................................
19
FLASHER ............................................................... ....20
FLASHER : CONSULT-III Function (BCM -
FLASHER) ...............................................................
20
COMB SW .............................................................. ....20
COMB SW : CONSULT-III Function (BCM -
COMB SW) ..............................................................
20
DIAGNOSIS SYSTEM (IPDM E/R) ...................22
Diagnosis Description ..............................................22
CONSULT - III Function (IPDM E/R) .......................24
COMPONENT DIAGNOSIS .........................27
POWER SUPPLY AND GROUND CIRCUIT ....27
BCM (BODY CONTROL MODULE) ...................... ....27
BCM (BODY CONTROL MODULE) : Diagnosis
Procedure ............................................................ ....
27
IPDM E/R (INTELLIGENT POWER DISTRIBU-
TION MODULE ENGINE ROOM) .......................... ....
28
IPDM E/R (INTELLIGENT POWER DISTRIBU-
TION MODULE ENGINE ROOM) : Diagnosis Pro-
cedure .................................................................. ....
28
HEADLAMP (HI) CIRCUIT ................................30
Description ...............................................................30
Revision: April 20092010 QX56

EXL-2
Component Function Check ...................................30
Diagnosis Procedure - Without Daytime Light Sys-
tem ..........................................................................
30
Diagnosis Procedure - With Daytime Light System
...
31
HEADLAMP (LO) CIRCUIT ...............................33
Description ........................................................... ...33
Component Function Check ...................................33
Diagnosis Procedure - Without Daytime Light Sys-
tem ..........................................................................
33
Diagnosis Procedure - With Daytime Light System
...
34
FRONT FOG LAMP CIRCUIT ...........................36
Description ........................................................... ...36
Component Function Check ...................................36
Diagnosis Procedure ..............................................36
PARKING LAMP CIRCUIT ................................38
Description ........................................................... ...38
Component Function Check ...................................38
Diagnosis Procedure - Without Daytime Light Sys-
tem ..........................................................................
38
Diagnosis Procedure - With Daytime Light System
...
41
TURN SIGNAL LAMP CIRCUIT ........................44
Description ........................................................... ...44
Component Function Check ...................................44
Diagnosis Procedure ..............................................44
OPTICAL SENSOR ...........................................47
Description ..............................................................47
Component Function Check ...................................47
Diagnosis Procedure ..............................................47
HEADLAMP AIMING SWITCH ..........................49
Description ........................................................... ...49
Diagnosis Procedure - Without Daytime Light Sys-
tem ..........................................................................
49
Diagnosis Procedure - With Daytime Light System
...
50
HEADLAMP .......................................................52
Wiring Diagram .................................................... ...52
DAYTIME LIGHT SYSTEM ................................56
Wiring Diagram .................................................... ...56
AUTO LIGHT SYSTEM ......................................62
Wiring Diagram .................................................... ...62
HEADLAMP AIMING SYSTEM (MANUAL) ......69
Wiring Diagram .................................................... ...69
FRONT FOG LAMP SYSTEM ...........................73
Wiring Diagram .................................................... ...73
TURN SIGNAL AND HAZARD WARNING
LAMP SYSTEM .............................................. ...
77
Wiring Diagram .................................................... ...77
PARKING, LICENSE PLATE AND TAIL
LAMPS SYSTEM ...............................................
84
Wiring Diagram .................................................... ...84
STOP LAMP ......................................................91
Wiring Diagram .................................................... ...91
BACK-UP LAMP ............................................ ...95
Wiring Diagram .................................................... ...95
TRAILER TOW .................................................100
Wiring Diagram .....................................................100
ECU DIAGNOSIS ......................................106
BCM (BODY CONTROL MODULE) ............... ..106
Reference Value .................................................. .106
Terminal Layout ....................................................109
Physical Values .....................................................109
Wiring Diagram .....................................................115
Fail Safe ...............................................................119
DTC Inspection Priority Chart .............................120
DTC Index ............................................................120
IPDM E/R (INTELLIGENT POWER DISTRI-
BUTION MODULE ENGINE ROOM) ................
122
Reference Value .................................................. .122
Terminal Layout ....................................................124
Physical Values .....................................................125
Wiring Diagram .....................................................130
Fail Safe ...............................................................133
DTC Index ............................................................135
SYMPTOM DIAGNOSIS ...........................136
EXTERIOR LIGHTING SYSTEM SYMPTOMS ..136
Symptom Table .................................................... .136
NORMAL OPERATING CONDITION ...............138
Description ........................................................... .138
BOTH SIDE HEADLAMPS DO NOT SWITCH
TO HIGH BEAM ................................................
139
Description ........................................................... .139
Diagnosis Procedure .............................................139
BOTH SIDE HEADLAMPS (LO) ARE NOT
TURNED ON .....................................................
140
Description ............................................................140
Diagnosis Procedure .............................................140
PARKING, LICENSE PLATE AND TAIL
LAMPS ARE NOT TURNED ON ......................
141
Description ........................................................... .141
Diagnosis Procedure .............................................141
BOTH SIDE FRONT FOG LAMPS ARE NOT
TURNED ON .....................................................
142
Description ............................................................142
Diagnosis Procedure .............................................142
Revision: April 20092010 QX56

HEADLAMPEXL-7
< FUNCTION DIAGNOSIS >
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FUNCTION DIAGNOSIS
HEADLAMP
System DiagramINFOID:0000000005146604
System DescriptionINFOID:0000000005369868
Control of the headlamp system operation is dependent upon t he position of the combination switch (lighting
and turn signal switch). When the combination switch (lighting and turn signal switch) is placed in the 2nd posi-
tion, the BCM (body control module) receives input requesting the headlamps and park lamps to illuminate.
This input is communicated to the IPDM E/R (intelligent power distribution module engine room) via the CAN
communication lines. The CPU (central processing unit) of the IPDM E/R controls the headlamp LH high,
headlamp RH high and headlamp low relay coils. When energiz ed, these relays direct power to the respective
headlamps, which then illuminate.
Component Parts LocationINFOID:0000000005146606
Component DescriptionINFOID:0000000005146607
XENON HEADLAMP
AWLIA1755GB
1. BCM M18, M20 (view with instrument
panel removed) 2. IPDM E/R E122, E123, E124 3. Combination switch (lighting and turn
signal switch) M28
4. Combination meter M23, M24
AWLIA1625ZZ
Revision: April 20092010 QX56

AUTO LIGHT SYSTEMEXL-11
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AUTO LIGHT SYSTEM
System DiagramINFOID:0000000005146612
System DescriptionINFOID:0000000005146613
• BCM (Body Control Module) controls auto light operati on according to signals from optical sensor, combina-
tion switch (lighting and turn signal switch) and ignition switch.
• IPDM E/R (Intelligent Power Distribution Module Engine Room) operates parking, license plate, tail and
headlamps according to CAN communication signals from BCM.
• Optical sensor detects ambient br ightness and converts light (lux) to voltage, then sends the optical sensor
signal to BCM.
OUTLINE
The auto light control system has an optical sensor that detects outside brightness.
When the combination switch (lighting and turn signal switch) is in AUTO position, it automatically turns ON/
OFF the parking, license plate, tail and headlamps in accordance with the ambient light. Sensitivity can be
adjusted in four steps. For the details of the setting, Refer to BCS-22, "
HEADLAMP : CONSULT-III Function
(BCM - HEAD LAMP)".
AWLIA1752GB
Revision: April 20092010 QX56