2007 INFINITI QX56 service

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ELECTRICAL
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CONTENTS
AUTO CRUISE CONTROL SYSTEM
ASCD
SERVICE INFORMATION ............................
3
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ................................................................
3
Description ................................................................3
ICC
SERVICE INFORMATION ............................
4
PRECAUTIONS ...................................................4
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
4
Precaution for ICC System Service ...........................4
PREPARATION ...................................................5
Special Service Tool .................................................5
DESCRIPTION ....................................................6
Outline .......................................................................6
Schematic .................................................................6
Component Description .............................................7
CAN Communication .................................................7
Switch Operation .......................................................7
ICC System Display ..................................................8
ACTION TEST .....................................................9
ICC System Running Test .........................................9
LASER BEAM AIMING ADJUSTMENT .............12
Outline of Laser Beam Aiming Adjustment Proce-
dure .........................................................................
12
Preparation ..............................................................12
Setting up the ICC Target Board .............................12
Sensor Adjustment ..................................................14
ELECTRICAL UNITS LOCATION ......................18
Component Parts and Harness Connector Loca-
tion ..........................................................................
18
WIRING DIAGRAM ...........................................19
Schematic ................................................................19
Wiring Diagram - ICC - ............................................20
TERMINALS AND REFERENCE VALUE .........24
Terminal and Reference Value for ICC Unit ............24
Terminal and Reference Value for ICC Sensor .......24
TROUBLE DIAGNOSIS — GENERAL DE-
SCRIPTION .......................................................
25
Work Flow ................................................................25
CONSULT-II Function (ICC) ....................................25
Self-Diagnostic Function ..........................................30
TROUBLE DIAGNOSIS FOR SELF-DIAG-
NOSTIC ITEMS .................................................
34
Diagnostic Trouble Code (DTC) Chart ....................34
DTC 11 CONTROL UNIT ........................................36
DTC 12 VDC CONTROL UNIT ................................36
DTC 20 CAN COMM CIRCUIT ................................37
DTC 31 POWER SUPPLY CIR1, DTC 34 POWER
SUPPLY CIR2 .........................................................
37
DTC 41 VHCL SPEED SE CIRC .............................38
DTC 43 VDC/TCS/ABS CIRC .................................38
DTC 45 BRAKE SW/STOP L SW ............................38
DTC 46 OPERATION SW CIRC .............................40
DTC 74 LASER BEAM OFF CNTR .........................41
DTC 90 STOP LAMP RLY FIX ................................41
DTC 92 ECM CIRCUIT ............................................45
DTC 96 NP RANGE ................................................45
DTC 97 AT CIRCUIT ...............................................46
DTC 98 GEAR POSITION .......................................46
DTC 102 LASER STAIN ..........................................47
DTC 103 LASER SENSOR FAIL .............................47
DTC 104 LASER AIMING INCMP ...........................48
DTC 107 LASER COMM FAIL ................................48
DTC 109 LASER HIGH TEMP ................................48
TROUBLE DIAGNOSIS FOR SYMPTOMS ......49
Symptom Chart ........................................................49

AUTOMATIC SPEED CONTROL DEVICE (ASCD)
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< SERVICE INFORMATION >[ASCD]
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SERVICE INFORMATION
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
DescriptionINFOID:0000000003533771
Regarding the information for ASCD system, refer to EC-30.

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< SERVICE INFORMATION >[ICC]
PRECAUTIONS
SERVICE INFORMATION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003533772
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 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 whether 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 inoperative, 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 incorrect removal and installation of the SRS, can lead to personal
injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.
Precaution for ICC System ServiceINFOID:0000000003533773
• Do not look straight into the laser beam discharger when adjusting laser beam aiming.
• Turn the ON/OFF switch OFF during chassis dynamometer testing.
• Do not remove, disassemble, or reposition the ICC sensor unless told to do so.
• Erase DTC when replacing parts of ICC system, then check the operation of ICC system after adjusting laser
beam aiming if necessary.

PREPARATION
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< SERVICE INFORMATION >[ICC]
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PREPARATION
Special Service ToolINFOID:0000000003533774
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
KV99110100
(J-45718)
ICC target boardPerforming laser beam aiming ad-
justment
PKIA0358J

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< SERVICE INFORMATION >[ICC]
DESCRIPTION
DESCRIPTION
OutlineINFOID:0000000003533775
The Intelligent Cruise Control (ICC) system automatically maintains a selected distance from the vehicle
ahead according to that vehicle's speed, or at the set speed, if the road ahead is clear.
The ICC function has two cruise control modes and brake assist (with preview function). The ICC system may
AUTO-CANCEL for various reasons, for example, when the windshield wipers are operating.
VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE
Vehicle-to-vehicle distance control mode, the same speed as other vehicles, can be maintained without the
constant need to adjust the operating speed as with a conventional cruise control system.
The system is intended to enhance the operation of the vehicle when following another vehicle in the same
lane and direction.
If the distance sensor detects a slower moving vehicle ahead, the system will reduce speed so that the vehicle
ahead can be followed at the selected distance.
The system automatically controls the throttle and applies the brakes (up to 25% of vehicle braking power) if
necessary.
The detection range of the sensor is approximately 120 m (390 ft) ahead.
Refer to Owner's Manual for Intelligent Cruise Control System operating instructions.
CONVENTIONAL (FIXED SPEED) CRUISE CONTROL MODE
Conventional (fixed speed) cruise control mode is cruising at preset speeds.
Refer to Owner's Manual for Intelligent Cruise Control System operation instructions.
BRAKE ASSIST (WITH PREVIEW FUNCTION)
When the force applied to brake pedal exceeds a certain level, the brake assist is activated and generates a
greater braking force than that of a conventional brake booster, even with light pedal force.
When the preview function identifies the need to apply the sudden brake by sensing the vehicle ahead in the
same lane and the distance and relative speed from it, it applies the brake pre-pressure before driver
depresses the brake pedal and improves brake response by reducing its free play.
Refer to Owner's Manual for Intelligent Cruise Control System operating instructions.
SchematicINFOID:0000000003533776
WKIA1976E

DESCRIPTION
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Component DescriptionINFOID:0000000003533777
CAN CommunicationINFOID:0000000003533778
SYSTEM DESCRIPTION
Refer to LAN-4 .
Switch OperationINFOID:0000000003533779
The system is operated by a master ON/OFF switch and four control switches, all mounted on the steering
wheel.
ComponentVehicle-to-vehicle
distance control
modeConventional
(fixed speed)
cruise control
modeBrake assist
(with preview
brake)Description
ICC unit×××Controls vehicle speed through ECM via CAN
communication.
ICC sensor××Irradiate laser beam, and receives reflected la-
ser beam to measure distance from preceding
vehicle.
ECM×××Transmits throttle position signal and ICC steer-
ing switch signal to ICC unit.
ABS actuator and electric
unit (control unit)×××Transmits wheel speed signal to ICC unit. Oper-
ates brake booster based on CAN communica-
tion.
Brake pressure sensor××Detects fluid pressure in master cylinder.
Brake booster××Adjusts brake fluid pressure based on command
from ABS actuator and electric unit (control unit).
BCM×Transmit front wiper request signal to ICC unit.
TCM××Transmits gear position signal and output shaft
revolution signal to ICC unit.
No. Switch nameDescription
1 ACCEL/RES switch Resumes set speed or increases speed incrementally.
2 COAST/SET switch Sets desired cruise speed, reduces speed incrementally.
3 ON/OFF switch Master switch to activate the system.
SKIA5973E

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< SERVICE INFORMATION >[ICC]
DESCRIPTION
ICC System Display
INFOID:0000000003533780
4 CANCEL switch Deactivates system without erasing set speed.
5 DISTANCE switch Changes the following distance from: Long, Middle, Short. No. Switch name Description
WKIA1977E
No. Component Description
1 Set vehicle speed indicator Indicates the set vehicle speed.
2 Vehicle ahead detection indicator Indicates whether it detects a vehicle ahead.
3 Set distance indicatorDisplay the selected distance between vehicles set with the DISTANCE
switch.
4 Own vehicle indicator Indicates the base vehicle.
5 ON/OFF switch indicator lamp (Green) Indicates that the system is ON.
6Intelligent cruise control system warning
lamp (Orange)The light comes on if there is a malfunction in the ICC system.
7 Cruise set switch indicator lamp Indicates that the conventional cruise control mode is on.

ACTION TEST
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< SERVICE INFORMATION >[ICC]
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ACTION TEST
ICC System Running TestINFOID:0000000003533781
VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE
SET CHECKING
1. Press the ON/OFF switch for less than 1.5 seconds.
2. Drive the vehicle between 40 km/h (25 MPH) and 144 km/h (89 MPH).
3. Push the COAST/SET switch.
4. Confirm that the desired speed is set as the COAST/SET switch is released.
NOTE:
• When there is no vehicle ahead, drive at the set speed steadily.
• When there is a vehicle ahead, control to maintain distance from the vehicle ahead, watching its speed.
• The set vehicle speed is displayed on the ICC system indicator in the combination meter.
CHECK FOR INCREASE OF THE CRUISING SPEED
1. Set vehicle-to-vehicle distance control mode at desired speed.
2. Check if the set speed increases by 1.6 km/h (1 MPH) as ACCEL/RES switch is pushed.
NOTE:
The maximum set speed of the vehicle-to-vehicle distance control mode is 144 km/h (89 MPH).
CHECK FOR DECREASE OF THE CRUISING SPEED
1. Set vehicle-to-vehicle distance control mode at desired speed.
2. Check if the set speed decreases by 1.6 km/h (1 MPH) as COAST/SET switch is pushed.
NOTE:
• Vehicle-to-vehicle distance control mode is automatically turned off when the driving speed lowers to 32 km/
h (20 MPH) due to the deceleration of the vehicle ahead.
• The minimum set speed of the vehicle-to-vehicle distance control mode is 40 km/h (25 MPH).
CHECK FOR THE CANCELLATION OF VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE (NORMAL DRIV-
ING CONDITION) IN THE FOLLOWING CASES:
1. When the brake pedal is depressed after the system is turned on.
2. When the selector lever is shifted to the "N" (Neutral) position.
3. When the system is turned off.
4. When CANCEL switch is operated.
CHECK FOR RESTORING THE SPEED THAT IS SET BY VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE
BEFORE CANCELLATION
1. Cancel the system by depressing the brake. Then, check that the speed before cancellation is restored
when pressing ACCEL/RES switch with vehicle speed at 40 km/h (25 MPH) or above.
2. Cancel the system by shifting the selector lever to “N”. Then, check if the speed set before the cancella-
tion is restored when ACCEL/RES switch is pressed.
3. Check if the speed previously set is restored when ACCEL/RES switch is operated when driving 40 km/h
(25 MPH) or above, after canceling vehicle-to-vehicle distance control mode by operating the CANCEL
switch.
CHECK ON/OFF SWITCH OPERATION