cruise control INFINITI QX56 2004 Factory Service Manual

-1QUICK REFERENCE INDEX AGENERAL INFORMATIONGIGeneral InformationBENGINEEMEngine MechanicalLUEngine Lubrication SystemCOEngine Cooling SystemECEngine Control SystemFLFuel SystemEXExhaust SystemACCAccelerator Control SystemCTRANSMISSION/
TRANSAXLEATAutomatic TransmissionDDRIVELINE/AXLETFTransferPRPropeller ShaftFFDFront Final DriveRFDRear Final DriveFAXFront AxleRAXRear AxleESUSPENSIONFSUFront SuspensionRSURear SuspensionWTRoad Wheels & TiresFBRAKESBRBrake SystemPBParking Brake SystemBRCBrake Control SystemGSTEERINGPSPower Steering SystemHRESTRAINTSSBSeat BeltsSRSSupplemental Restraint System (SRS)IBODYBLBody, Lock & Security SystemGWGlasses, Window System & MirrorsRFRoofEIExterior & InteriorIPInstrument PanelSESeatAPAdjustable PedalsJAIR CONDITIONERATCAutomatic Air ConditionerKELECTRICALSCStarting & Charging SystemLTLighting SystemDIDriver Information SystemWWWiper, Washer & HornBCSBody Control SystemLANLAN SystemAVAudio Visual, Navigation & Telephone SystemACSAuto Cruise Control SystemPGPower Supply, Ground & Circuit ElementsLMAINTENANCEMAMaintenanceMINDEXIDXAlphabetical IndexEdition: February 2004
Revision: August 2007BDACEFGHIJKLM

ACS-1
AUTO CRUISE CONTROL SYSTEM
K ELECTRICAL
CONTENTS
C
D
E
F
G
H
I
J
L
M
SECTION ACS
A
B
ACS
Revision: August 20072004 QX56
ASCD
AUTOMATIC SPEED CONTROL DEVICE (ASCD) ..... 3
Description ............................................................... 3
ICC
PRECAUTIONS .......................................................... 4
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 4
Precautions for ICC System Service ........................ 4
Wiring Diagrams and Trouble Diagnosis .................. 4
PREPARATION ........................................................... 5
Special Service Tool ................................................. 5
DESCRIPTION ............................................................ 6
Outline ...................................................................... 6
VEHICLE-TO-VEHICLE DISTANCE CONTROL
MODE ................................................................... 6
CONVENTIONAL (FIXED SPEED) CRUISE
CONTROL MODE ................................................. 6
BRAKE ASSIST (WITH PREVIEW FUNCTION) ..... 6
System Diagram ....................................................... 7
Components Description .......................................... 7
CAN Communication ................................................ 7
SYSTEM DESCRIPTION ...................................... 7
Switch Operation ...................................................... 8
ICC System Display ................................................. 8
ACTION TEST ............................................................ 9
ICC System Running Test ........................................ 9
VEHICLE-TO-VEHICLE DISTANCE CONTROL
MODE ................................................................... 9
CONVENTIONAL (FIXED SPEED) CRUISE
CONTROL MODE ............................................... 10
LASER BEAM AIMING ADJUSTMENT ................... 12
Outline of Laser Beam Aiming Adjustment Proce-
dure ........................................................................ 12
Preparation ............................................................. 12
Setting up the ICC Target Board ............................ 12
ADJUSTING HEIGHT OF THE ICC TARGET
BOARD ............................................................... 12ADJUSTING THE POSITION OF THE ICC TAR-
GET BOARD STRING ......................................... 13
POSITIONING THE ICC TARGET BOARD ........ 13
Sensor Adjustment ................................................. 14
CHECK AFTER THE ADJUSTMENT .................. 17
ELECTRICAL UNITS LOCATION ............................ 18
Component Parts and Harness Connector Location ... 18
WIRING DIAGRAM ................................................... 19
Schematic ............................................................... 19
Wiring Diagram — ICC — ...................................... 20
TERMINALS AND REFERENCE VALUE ................. 25
Terminals and Reference Values for ICC Unit ........ 25
Terminals and Reference Values for ICC Sensor ... 25
TROUBLE DIAGNOSIS — GENERAL DESCRIP-
TION .......................................................................... 26
Work Flow ............................................................... 26
CONSULT-II Function (ICC) ................................... 27
CONSULT-II OPERATION ................................... 27
WORK SUPPORT ............................................... 28
SELF-DIAGNOSTIC RESULTS ........................... 28
DATA MONITOR ................................................. 29
ACTIVE TEST ..................................................... 30
Self-Diagnostic Function ......................................... 32
WITH CONSULT-II .............................................. 32
WITHOUT CONSULT-II ....................................... 32
SELF-DIAGNOSIS BY ICC SYSTEM DISPLAY
WILL NOT RUN ................................................... 34
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ........................................................................ 36
Diagnostic Trouble Code (DTC) Chart ................... 36
DTC 11 CONTROL UNIT ....................................... 37
DTC 12 VDC CONTROL UNIT ............................... 37
DTC 20 CAN COMM CIRCUIT ............................... 38
DTC 31 POWER SUPPLY CIR 1, DTC 34 POWER
SUPPLY CIR 2 ....................................................... 38
DTC 41 VHCL SPEED SE CIRC ............................ 39
DTC 43 VDC/TCS/ABS CIRC ................................ 39
DTC 45 BRAKE SW/STOP L SW ........................... 40
DTC 46 OPERATION SW CIRC ............................. 41
DTC 74 LASER BEAM OFF CENTER ................... 42

ACS-6
[ICC]
DESCRIPTION
Revision: August 20072004 QX56
DESCRIPTIONPFP:00000
OutlineEKS007RI
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 operated at the low speed
(LO) or high speed (HI) position.
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 390 ft (120 m) 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.

DESCRIPTION
ACS-7
[ICC]
C
D
E
F
G
H
I
J
L
MA
B
ACS
Revision: August 20072004 QX56
System DiagramEKS007RJ
Components DescriptionEKS007RK
CAN CommunicationEKS007RO
SYSTEM DESCRIPTION
Refer to LAN-5, "CAN COMMUNICATION" .
WKIA1976E
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
laser 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.
Operates brake booster based on CAN commu-
nication.
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.

ACS-8
[ICC]
DESCRIPTION
Revision: August 20072004 QX56
Switch OperationEKS007RM
The system is operated by a master ON/OFF switch and four control switches, all mounted on the steering
wheel.
ICC System DisplayEKS007RN
No. Switch name Description
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.
4 CANCEL switch Deactivates system without erasing set speed.
5 DISTANCE switch Changes the following distance from: Long, Middle, Short.
SKIA5973E
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
ACS-9
[ICC]
C
D
E
F
G
H
I
J
L
MA
B
ACS
Revision: August 20072004 QX56
ACTION TESTPFP:00000
ICC System Running TestEKS007YE
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 25 MPH (40 km/h) and 89 MPH (144 km/h).
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 MPH (1 km/h) as ACCEL/RES switch is pushed.
NOTE:
The maximum set speed of the vehicle-to-vehicle distance control mode is 89 MPH (144 km/h).
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 MPH (1 km/h) as COAST/SET switch is pushed.
NOTE:

Vehicle-to-vehicle distance control mode is automatically turned off when the driving speed lowers to 20
MPH (32 km/h) due to the deceleration of the vehicle ahead.

The minimum set speed of the vehicle-to-vehicle distance control mode is 25 MPH (40 km/h).
CHECK FOR THE CANCELLATION OF VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE
(NORMAL DRIVING CONDITION) IN THE FOLLOWING CASES:
1. When the brake pedal is depressed after the system is turned on.
2. When the A/T select lever is shifted into gears other than “D”, including manual shifts.
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 25 MPH (40 km/h) or above.
2. Cancel the system by shifting the select lever into other than “D”. Then, check if the speed set before the
cancellation 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 25 MPH
(40 km/h) or above, after canceling vehicle-to-vehicle distance control mode by operating the CANCEL
switch.
CHECK ON/OFF SWITCH OPERATION
1. Start the engine. Then, check that the following operations are
performed correctly.
2. Vehicle-to-vehicle distance control mode is displayed when ON/
OFF switch is pressed ON. Vehicle-to-vehicle distance control
mode goes off when ON/OFF switch is turned to OFF.
3. Turn off the ignition switch while ON/OFF switch is ON. Turn the
ignition switch back to ON and confirm that CRUISE lamp and
ICC system display are OFF.
WKIA1978E

ACS-10
[ICC]
ACTION TEST
Revision: August 20072004 QX56
CHECK FOR ACCEL/RES, COAST/SET, CANCEL SWITCHES
1. Check if ACCEL/RES, COAST/SET, CANCEL switches operate smoothly.
2. Check if switch buttons rebound as the buttons are released.
CHECK FOR DISTANCE SWITCH
1. Start the engine.
2. Press the ON/OFF switch for less than 1.5 seconds.
3. Press the DISTANCE switch.
4. Check if the set distance indicator changes display in order of:
(long)→(middle)→(short).
NOTE:
The set distance indicator shows long immediately after the engine starts.
CONVENTIONAL (FIXED SPEED) CRUISE CONTROL MODE
SET CHECKING
1. Press the ON/OFF switch for more than 1.5 seconds.
2. Drive the vehicle between 25 MPH (40 km/h) and 89 MPH (144 km/h).
3. Push the COAST/SET switch.
4. Confirm that the desired speed is set when the COAST/SET switch is released.
NOTE:

ICC system display in the combination meter shows nothing.
SKIA6178E

ACTION TEST
ACS-11
[ICC]
C
D
E
F
G
H
I
J
L
MA
B
ACS
Revision: August 20072004 QX56
CHECK FOR INCREASE OF THE CRUISING SPEED
1. Set the conventional (fixed speed) cruise control mode at desired speed.
2. Check if the set speed increases by 1 MPH (1.6 km/h) as ACCEL/RES switch is pushed.
NOTE:

If the ACCEL/RES switch is held, the vehicle speed increases until the switch is released.

The maximum set speed is 89 MPH (144 km/h).
CHECK FOR DECREASE OF THE CRUISING SPEED
1. Set the conventional (fixed speed) cruise control mode at desired speed.
2. Check if the set speed decreases by 1 MPH (1.6 km/h) as COAST/SET switch is pushed.
NOTE:

Conventional (fixed speed) cruise control mode is automatically turned off when the driving speed lowers
to 20 MPH (32 km/h).

The lowest set speed is 25 MPH (40 km/h).
CHECK FOR THE CANCELLATION OF CONVENTIONAL (FIXED SPEED) CRUISE CONTROL
MODE (NORMAL DRIVING CONDITION) IN THE FOLLOWING CASES:
Refer to ACS-9, "CHECK FOR THE CANCELLATION OF VEHICLE-TO-VEHICLE DISTANCE CONTROL
MODE (NORMAL DRIVING CONDITION) IN THE FOLLOWING CASES:"
CHECK FOR RESTORING THE SPEED THAT IS SET BY CONVENTIONAL (FIXED SPEED)
CRUISE CONTROL MODE BEFORE ICC CANCELLATION
Refer to ACS-9, "CHECK FOR RESTORING THE SPEED THAT IS SET BY VEHICLE-TO-VEHICLE DIS-
TANCE CONTROL MODE BEFORE CANCELLATION"
CHECK ON/OFF SWITCH OPERATION
1. Start the engine. Then, check that the following operations are
performed correctly.
2. CRUISE lamp (green) illuminates and ICC system indicator
goes off when ON/OFF switch is pressed ON for more than 1.5
seconds. The CRUISE lamp goes off when ON/OFF switch is
turned to OFF.
3. Turn off the ignition switch while ON/OFF switch is ON. Turn the
ignition switch back to ON and confirm that CRUISE lamp is
OFF.
CHECK FOR ACCEL/RES, COAST/SET, CANCEL SWITCHES
1. Check if ACCEL/RES, COAST/SET, CANCEL switches operate smoothly.
2. Check if switch buttons rebound as the buttons are released.
WKIA2038E

TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
ACS-29
[ICC]
C
D
E
F
G
H
I
J
L
MA
B
ACS
Revision: August 20072004 QX56
DATA MONITOR
Operation Procedure
1. Touch “DATA MONITOR” on the "SELECT DIAG MODE"
screen.
2. Touch “ECU INPUT SIGNALS”, “MAIN SIGNALS“, or “SELEC-
TION FROM MENU” on "SELECT MONITOR ITEM" screen.
Monitored Item
×: Applicable
WDIA0084E
Monitored Item [unit] MAIN SIGNALSECU
INPUT
SIGNALSSELECTION
FROM MENUDescription
VHCL SPEED SE
[km/h] or [mph]×××Indicates vehicle speed calculated from wheel
speed sensor signal.
SET VHCL SPD
[km/h] or [mph]××Indicates set vehicle speed stored in ICC unit.
THRTL OPENING
[%]×××Indicates throttle angle calculated from signal volt-
age of throttle position sensor.
ENGINE RPM
[rpm]××Indicates engine speed read by ICC unit via CAN
communication (ECM transmits engine speed via
CAN communication).
DISTANCE ADJ
[SHOR/MID/LONG]×××Indicates set distance stored in ICC unit.
WIPER SW
[OFF/LOW/HIGH]××Indicates wiper [OFF/LOW/HIGH] status.
MAIN SW
[ON/OFF]×××Indicates [ON/OFF] status as judged from control
switch signal.
SET/COAST SW
[ON/OFF]×××Indicates [ON/OFF] status as judged from control
switch signal.
CANCEL SW
[ON/OFF]×××Indicates [ON/OFF] status as judged from control
switch signal.
RESUME/ACC SW
[ON/OFF]×××Indicates [ON/OFF] status as judged from control
switch signal.
CRUISE OPE
[ON/OFF]××Indicates whether vehicle speed is being con-
trolled or not (ON means “controlling”).
BRAKE SW
[ON/OFF]×××Indicates [ON/OFF] status as judged from ICC
brake switch signal.
STOP LAMP SW
[ON/OFF]×××Indicates [ON/OFF] status as judged from stop
lamp switch signal.
RELEASE SW NO
[ON/OFF]
××Indicates [ON/OFF] status as judged from release
switch signal.
ON when brake is depressed.
OFF when brake is not depressed.
RELEASE SW NC
[ON/OFF]
××Indicates [ON/OFF] status as judged from release
switch signal.
OFF when brake is depressed.
ON when brake is not depressed.
IDLE SW
[ON/OFF]××Indicates [ON/OFF] status of idle switch read by
ICC unit via CAN communication (ECM transmits
ON/OFF status via CAN communication).

ACS-36
[ICC]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSPFP:00000
Diagnostic Trouble Code (DTC) ChartEKS007X2
×:Applicable
DTC
No.CONSULT-II screen termsICC sys-
tem
warning
lampFail-safe
Malfunctions detected where...Refer-
ence
page Vehicle-
to-vehi-
cle dis-
tance
control
modeConven-
tional
(fixed
speed)
cruise
control
modeBrake
assist
(with pre-
view
function)
11 CONTROL UNIT××××

ICC unit internal malfunctionACS-37
12 VDC CONTROL UNIT××××

VDC malfunction

Brake booster signal harness is
open or shortedACS-37
20 CAN COMM CIRCUIT××××
ICC unit detected CAN communi-
cation malfunctionACS-38
31 POWER SUPPLY CIR1××××
ICC unit power supply voltage is
excessively low (less than 8V)ACS-38
34 POWER SUPPLY CIR2××××
ICC unit power supply voltage is
excessively high.ACS-38
41 VHCL SPEED SE CIRC××××

Wheel sensor malfunction

ABS actuator and electric unit
(control unit) malfunction

AT vehicle speed sensor mal-
function

TCM malfunctionACS-39
43 VDC/TCS/ABS CIRC××××
VDC/TCS/ABS system malfunc-
tionACS-39
45 BRAKE SW/ STOP L SW××××

ICC brake switch or stop lamp
switch harness is open or shorted

ICC brake switch or stop lamp
switch is stuck to OFF

ICC brake switch or stop lamp
switch is stuck to ONACS-40
46 OPERATION SW CIRC×××

ICC steering switch harness or
spiral cable is open or shorted

ICC steering switch malfunctionACS-41
74 LASER BEAM OFF CNTR×× ×
Laser beam of ICC sensor is off
the aiming pointACS-42
90 STOP LAMP RLY FIX×× ×
Normally open terminal of stop
lamp relay is stuckACS-43
92 ECM CIRCUIT××××

ECM malfunction

Accelerator pedal position sensor
malfunction

ICC unit malfunctionACS-47
96 NP RANGE×××

Park/neutral position switch har-
ness is open or shorted

Park/neutral position switch mal-
function

TCM malfunctionACS-48
97 AT CIRCUIT××
TCM malfunctionACS-48