2004 INFINITI QX56 Electric

AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-647
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Revision: August 20072004 QX56
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionUBS00HE7
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without pressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/h
(25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
SET OPERATION
Press ON/OFF(MAIN) switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press COAST/SET switch. (Then SET indicator in combination meter illuminates.)
ACCEL OPERATION
If the ACCEL/RESUME switch is pressed during cruise control driving, increase the vehicle speed until the
switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.

CANCEL switch is pressed

More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)

Brake pedal is depressed

Selector lever is changed to N, P, R position

Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed

VDC/TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.

Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing COAST/SET switch or ACCEL/
RESUME switch.

Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If ON/OFF(MAIN) switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled
and vehicle speed memory will be erased.
COAST OPERATION
When the COAST/SET switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switchGear position
Combination meter* Vehicle speed
TCM* Powertrain revolution

EC-648Revision: August 2007
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
2004 QX56
RESUME OPERATION
When the ACCEL/RESUME switch is pressed after cancel operation other than pressing ON/OFF(MAIN)
switch is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition
must meet following conditions.

Brake pedal is released

A/T selector lever is in other than P and N positions

Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component DescriptionUBS00HE8
ASCD STEERING SWITCH
Refer to EC-517 .
ASCD BRAKE SWITCH
Refer to EC-534 , and EC-621 .
STOP LAMP SWITCH
Refer to EC-534 , EC-551 and EC-621 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-365 , EC-367 , EC-373 and EC-378 .
ASCD INDICATOR
Refer to EC-628 .

SERVICE DATA AND SPECIFICATIONS (SDS)
EC-649
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Revision: August 20072004 QX56
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureUBS00HE9
Idle Speed and Ignition TimingUBS00HEA
*1: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights and heater fan)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueUBS00HEB
Mass Air Flow SensorUBS00HEC
*: Engine is warmed up to normal operating temperature and running under no-load.
Intake Air Temperature SensorUBS00HED
Engine Coolant Temperature SensorUBS00HEE
A/F Sensor 1 HeaterUBS00HEF
Heated Oxygen sensor 2 HeaterUBS00HEG
Crankshaft Position Sensor (POS)UBS00HEH
Refer to EC-260, "Component Inspection" .
Camshaft Position Sensor (PHASE)UBS00HEI
Refer to EC-266, "Component Inspection" .
Throttle Control MotorUBS00HEJ
Fuel pressure at idling kPa (kg/cm2 , psi)Approximately 350 (3.57, 51)
Target idle speed
No-load*1 (in P or N position)650±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15° ± 5° BTDC
Condition Calculated load value % (Using CONSULT-II or GST)
At idle14.0 - 33.0
At 2,500 rpm12.0 - 25.0
Supply voltage Battery voltage (11 - 14V)
Output voltage at idle1.1 - 1.4V*
Mass air flow (Using CONSULT-II or GST)3.0 - 9.0 g·m/sec at idle*
9.0 - 28.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.9 - 2.1
80 (176)0.31 - 0.37
Temperature °C (°F) Resistance kΩ
20 (68)2.1 - 2.9
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Resistance [at 25°C (77°F)] 3.3 - 4.3Ω
Resistance [at 25°C (77°F)] 5.0 - 7.0Ω
Resistance [at 25°C (77°F)] Approximately 1 - 15Ω

PRECAUTIONS
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Revision: August 20072004 QX56
PRECAUTIONSPFP:00001
Service NoticeEIS002X1

When removing or installing various parts, place a cloth or padding on the vehicle body to prevent
scratches.

Handle trim, molding, instruments, grille, etc. carefully during removing or installing. Be careful not to soil
or damage them.

Apply sealing compound where necessary when installing parts.

When applying sealing compound, be careful that the sealing compound does not protrude from parts.

When replacing any metal parts (for example body outer panel, members, etc.), be sure to take rust pre-
vention measures.
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EIS002X2
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.
WA RN ING:

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 per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal 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
harness connectors.

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SQUEAK AND RATTLE TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
DUPLICATE THE NOISE AND TEST DRIVE
If possible, drive the vehicle with the customer until the noise is duplicated. Note any additional information on
the Diagnostic Worksheet regarding the conditions or location of the noise. This information can be used to
duplicate the same conditions when you confirm the repair.
If the noise can be duplicated easily during the test drive, to help identify the source of the noise, try to dupli-
cate the noise with the vehicle stopped by doing one or all of the following:
1. Close a door.
2. Tap or push/pull around the area where the noise appears to be coming from.
3. Rev the engine.
4. Use a floor jack to recreate vehicle “twist”.
5. At idle, apply engine load (electrical load, drive position on A/T model).
6. Raise the vehicle on a hoist and hit a tire with a rubber hammer.

Drive the vehicle and attempt to duplicate the conditions the customer states exist when the noise occurs.

If it is difficult to duplicate the noise, drive the vehicle slowly on an undulating or rough road to stress the
vehicle body.
CHECK RELATED SERVICE BULLETINS
After verifying the customer concern or symptom, check ASIST for Technical Service Bulletins (TSBs) related
to that concern or symptom.
If a TSB relates to the symptom, follow the procedure to repair the noise.
LOCATE THE NOISE AND IDENTIFY THE ROOT CAUSE
1. Narrow down the noise to a general area. To help pinpoint the source of the noise, use a listening tool
(Chassis Ear: J-39570, Engine Ear: J-39565 and mechanics stethoscope).
2. Narrow down the noise to a more specific area and identify the cause of the noise by:

Removing the components in the area that you suspect the noise is coming from.
Do not use too much force when removing clips and fasteners, otherwise clips and fasteners
can be broken or lost during the repair, resulting in the creation of new noise.

Tapping or pushing/pulling the component that you suspect is causing the noise.
Do not tap or push/pull the component with excessive force, otherwise the noise will be elimi-
nated only temporarily.

Feeling for a vibration with your hand by touching the component(s) that you suspect is (are) causing
the noise.

Placing a piece of paper between components that you suspect are causing the noise.

Looking for loose components and contact marks.
Refer to EI-7, "
Generic Squeak and Rattle Troubleshooting" .
REPAIR THE CAUSE

If the cause is a loose component, tighten the component securely.

If the cause is insufficient clearance between components:
–Separate components by repositioning or loosening and retightening the component, if possible.
–Insulate components with a suitable insulator such as urethane pads, foam blocks, felt cloth tape or ure-
thane tape. A NISSAN Squeak and Rattle Kit (J-43980) is available through your authorized NISSAN
Parts Department.
CAUTION:
Do not use excessive force as many components are constructed of plastic and may be damaged.
Always check with the Parts Department for the latest parts information.
The following materials are contained in the NISSAN Squeak and Rattle Kit (J-43980). Each item can be
ordered separately as needed.
URETHANE PADS [1.5 mm (0.059 in) thick]
Insulates connectors, harness, etc.
76268-9E005: 100 x 135 mm (3.94 x 5.31 in)/76884-71L01: 60 x 85 mm (2.36 x 3.35 in)/76884-71L02: 15 x 25
mm (0.59 x 0.98 in)
INSULATOR (Foam blocks)
Insulates components from contact. Can be used to fill space behind a panel.

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LICENSE LAMP FINISHER
Revision: August 20072004 QX56
LICENSE LAMP FINISHERPFP:84810
Removal and InstallationEIS00300
1. Remove back door trim. Refer to EI-41, "BACK DOOR TRIM" .
2. Disconnect electrical harnesses from connectors.
3. Remove harnesses with bulbs from license lamps.
4. Remove nuts and screws from license lamp finisher.
5. Release clips and remove license lamp finisher.
Installation is in the reverse order of removal.
1. Rubber seal 2. Plastic clip 3. Nut
4. License lamp finisher 5. License plate fastener 6. Screw
7. Fastener 8. Rubber seal
WIIA0270E

INTAKE MANIFOLD
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Revision: August 20072004 QX56
INTAKE MANIFOLDPFP:14003
Removal and InstallationEBS00ILF
REMOVAL
1. Partially drain the engine coolant. Refer to MA-12, "DRAINING ENGINE COOLANT" .
WAR NIN G:
To avoid the danger of being scalded, never drain the engine coolant when the engine is hot.
2. Remove the engine room cover using power tool. Refer to EM-11, "
REMOVAL" .
3. Release the fuel pressure. Refer to EC-46, "
FUEL PRESSURE RELEASE" .
4. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
5. Disconnect the fuel tube quick connector on the engine side.
1. Intake manifold 2. PCV hose 3. Gasket
4. Electric throttle control actuator 5. Water hose 6. Water hose
7. PCV hose 8. EVAP hose 9. EVAP canister purge control sole-
noid valve
10. Bracket 11. Gasket
KBIA2461E
LBIA0395E

EM-16Revision: August 2007
INTAKE MANIFOLD
2004 QX56

Perform the following steps to disconnect the quick connector
using Tool.
a. Remove quick connector cap (engine side only).
b. With the sleeve side of Tool facing quick connector, install Tool
onto fuel tube.
c. Insert Tool into quick connector until sleeve contacts and goes
no further. Hold the Tool in that position.
CAUTION:
Inserting the Tool hard will not disconnect quick connector.
Hold Tool where it contacts and goes no further.
d. Draw and pull out quick connector straight from fuel tube.
CAUTION:

Pull quick connector holding A position in illustration.

Do not pull with lateral force applied. O-ring inside quick connector may be damaged.

Prepare container and cloth beforehand as fuel will leak out.

Avoid fire and sparks.

Be sure to cover openings of disconnected pipes with plug or plastic bag to avoid fuel leakage
and entry of foreign materials.
6. Remove or disconnect harnesses, brackets, vacuum hose, vacuum gallery and PCV hose and tube from
intake manifold.
7. Remove electric throttle control actuator by loosening bolts diagonally.
CAUTION:

Handle carefully to avoid any damage to the electric throttle control actuator.

Do not disassemble.
8. Remove the fuel injectors and fuel tube assembly. Refer to EM-29, "
Removal and Installation" .
9. Loosen the bolts in reverse order shown using power tool.
10. Remove the intake manifold.
CAUTION:
Cover engine openings to avoid entry of foreign materials.Tool number : 16441 6N210 (J-45488)
SBIA0354E
WBIA0604E
KBIA2462E