brake INFINITI QX4 2001 Factory Service Manual
Page 1408 of 2395
IA/T shift solenoid valve A
Coast OperationNBEL0216S0204When the SET/COAST switch is depressed during cruise control driving, ASCD actuator returns the throttle
cable to decrease vehicle set speed until the switch is released. And then ASCD will keep the new set speed.
Accel OperationNBEL0216S0205When the RESUME/ACCEL switch is depressed, power is supplied
Ifrom ASCD steering switch terminal 3
Ito ASCD control unit terminal 24.
If the RESUME/ACCEL switch is depressed during cruise control driving, ASCD actuator pulls the throttle cable
to increase the vehicle speed until the switch is released or vehicle speed is reached to maximum controlled
speed by the system. And then ASCD will keep the new set speed.
Cancel OperationNBEL0216S0206When any of following condition exists, cruise operation will be canceled.
ICANCEL switch is depressed. (Power supply to ASCD control unit terminals 11 and 24)
IBrake pedal is depressed. (Power supply to ASCD control unit terminal 23 from stop lamp switch)
IBrake pedal is depressed or A/T selector lever is shifted to P or N position. (Power supply to ASCD con-
trol unit terminal 8 is interrupted.)
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operation will be canceled and vehicle
speed memory will be erased.
Resume OperationNBEL0216S0207When the RESUME/ACCEL switch is depressed after cancel operation other than depressing MAIN switch is
performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must
meet following conditions.
IBrake pedal is released.
IA/T selector lever is in other than P and N position.
IVehicle speed is between 40 km/h (25 MPH) and 144 km/h (89 MPH).
ASCD PUMP OPERATIONNBEL0216S03The ASCD pump consists of a vacuum motor, an air valve and a release valve. When the ASCD activates,
power is supplied
Ifrom terminal 12 of ASCD control unit
Ito ASCD pump terminal 1.
Ground is supplied to vacuum motor, air valve and release valve from ASCD control unit depending on the
operated condition as shown in the below table.
The pump is connected to ASCD actuator by vacuum hose. When the ASCD pump is activated, the ASCD
pump vacuum the diaphragm of ASCD actuator to control throttle cable.
Air valve (*1) Release valve (*1) Vacuum motorActuator inner pres-
sure
ASCD not operating Open Open Stopped Atmosphere
ASCD operatingReleasing throttle
cableOpen Closed Stopped Vacuum
Holding throttle
positionClosed Closed Stopped Vacuum (*2)
Pulling throttle cable Closed Closed Operated Vacuum
*1: When power and ground is supplied, valve is closed.
*2: Set position held.
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
System Description (Cont'd)
EL-223
Page 1414 of 2395
SEL255W
Fail-safe SystemNBEL0217DESCRIPTIONNBEL0217S01When the fail-safe system senses a malfunction, it deactivates
ASCD operation. The SET indicator in the combination meter will
then flash.
MALFUNCTION DETECTION CONDITIONSNBEL0217S02
Detection conditionsASCD operation during malfunc-
tion detection
IASCD steering (RESUME/ACCEL, CANCEL, SET/COAST) switch is stuck.
IVacuum motor ground circuit or power circuit is open or shorted.
IAir valve ground circuit or power circuit is open or shorted.
IRelease valve ground circuit or power circuit is open or shorted.
IVehicle speed sensor is faulty.
IASCD control unit internal circuit is malfunctioning.IASCD is deactivated.
IVehicle speed memory is can-
celed.
IASCD brake switch or stop lamp switch is faulty.IASCD is deactivated.
IVehicle speed memory is not
canceled.
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Fail-safe System
EL-229
Page 1415 of 2395
Trouble DiagnosesNBEL0218SYMPTOM CHARTNBEL0218S01
PROCEDURE Diagnostic procedure
REFERENCE PAGE (EL- ) 231 232 233 234 235 235 237
SYMPTOM
FAIL-SAFE SYSTEM CHECK
POWER SUPPLY AND GROUND CIRCUIT CHECK
ASCD BRAKE/STOP LAMP SWITCH CHECK
ASCD STEERING SWITCH CHECK
VEHICLE SPEED SENSOR CHECK
ASCD PUMP CIRCUIT CHECK
ASCD ACTUATOR/PUMP CHECK
ASCD cannot be set. (ªCRUISEº indica-
tor lamp does not ON.)XXH3
ASCD cannot be set. (ªSETº indicator
lamp does not blink.)XXX
ASCD cannot be set. (ªSETº indicator
lamp blinks.H1)X XXXX
Vehicle speed does not decrease after
SET/COAST switch has been pressed.XX
Vehicle speed does not return to the set
speed after RESUME/ACCEL switch has
been pressed.H2XX
Vehicle speed does not increase after
RESUME/ACCEL switch has been
pressed.XX
System is not released after CANCEL
switch (steering) has been pressed.XX
Large difference between set speed and
actual vehicle speed.XXX
Deceleration is greatest immediately
after ASCD has been set.XXX
H1: It indicates that system is in fail-safe. After completing diagnostic procedures, perform ªFAIL-SAFE SYSTEM CHECKº (EL-231) to
verify repairs.
H2: If vehicle speed is greater than 40 km/h (25 MPH) after system has been released, pressing RESUME/ACCEL switch returns vehicle
speed to the set speed previously achieved. However, doing so when the ASCD main switch is turned to ªOFFº, vehicle speed will not
return to the set speed since the memory is canceled.
H3: Check only main switch built-in steering switch.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Trouble Diagnoses
EL-230
Page 1416 of 2395
SEL417V
FAIL-SAFE SYSTEM CHECK=NBEL0218S021. Turn ignition switch to ON position.
2. Turn ASCD main switch to ON and check if the SET indicator
blinks.
If the indicator lamp blinks, check the following.
IASCD steering switch. Refer to EL-234.
SEL767P
3. Drive the vehicle at more than 40 km/h (25 MPH) and push
SET/COAST switch.
If the indicator lamp blinks, check the following.
IVehicle speed sensor. Refer to EL-235.
IASCD pump circuit. Refer to EL-235.
IReplace control unit.
SAT797A
4. Depress brake pedal slowly (brake pedal should be depressed
more than 5 seconds).
If the indicator lamp blinks, check the following.
IASCD brake/stop lamp switch. Refer to EL-233.
5. END. (System is OK.)
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Trouble Diagnoses (Cont'd)
EL-231
Page 1418 of 2395
ASCD BRAKE/STOP LAMP SWITCH CHECK=NBEL0218S04
1 CHECK ASCD BRAKE SWITCH CIRCUIT
1. Disconnect ASCD control unit harness connector.
2. Turn ignition switch ON.
3. Check voltage between ASCD control unit harness connector terminal 8 and ground.
SEL258WD
OK or NG
OK©GO TO 2.
NG©Check the following.
IASCD brake switch
Refer to ªElectrical Component Inspectionº (EL-239).
IPark/neutral position switch
Refer to ªElectrical Component Inspectionº (EL-239).
IPark/neutral position relay
IHarness for open or short
2 CHECK STOP LAMP SWITCH CIRCUIT
1. Disconnect ASCD control unit harness connector.
2. Check voltage between ASCD control unit harness connector terminal 23 and ground.
SEL259WB
Refer to wiring diagram in EL-226.
OK or NG
OK©ASCD brake/stop lamp switch is OK.
NG©Check the following.
I10A fuse [No. 14, located in the fuse block (J/B)]
IHarness for open or short between ASCD control unit and stop lamp switch
IHarness for open or short between fuse and stop lamp switch
IStop lamp switch
Refer to ªElectrical Component Inspectionº (EL-239).
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Trouble Diagnoses (Cont'd)
EL-233
Page 1424 of 2395
SEL302X
Electrical Component Inspection=NBEL0219ASCD BRAKE SWITCH AND STOP LAMP SWITCHNBEL0219S02
ConditionContinuity
ASCD brake
switchStop lamp switch
When brake pedal is depressed No Yes
When brake pedal is released Yes No
Check each switch after adjusting brake pedal Ð refer to BR-14,
ªBRAKE PEDAL AND BRACKETº.
SEL303X
PARK/NEUTRAL POSITION SWITCHNBEL0219S03
A/T selector lever positionContinuity
Between terminals 1 and 2
ªPº Yes
ªNº Yes
Except ªPº and ªNº No
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Electrical Component Inspection
EL-239
Page 1642 of 2395
NBEL0145
Use the chart below to find out what each wiring
diagram code stands for.
Refer to the wiring diagram code in the alphabetical
index to find the location (page number) of each
wiring diagram.
Code Section Wiring Diagram Name
1STSIG AT A/T 1ST Signal
2NDSIG AT A/T 2ND Signal
3RDSIG AT A/T 3RD Signal
4THSIG AT A/T 4TH Signal
A/C, A HA Auto Air Conditioner
AAC/V EC IACV-AAC Valve
ABS BR Anti-lock Brake System
AP/SEN EC Absolute Pressure Sensor
ASCD EL Automatic Speed Control Device
AT/C EC A/T Control
ATDIAG EC A/T Diagnosis Communication
Line
AT/IND EL A/T Indicator Lamp
AUDIO EL Audio
AUT/DP EL Automatic Drive Positioner
BA/FTS AT A/T Fluid Temperature Sensor
and TCM Power Supply
BACK/L EL Back-up Lamp
BYPS/V EC Vacuum Cut Valve Bypass Valve
CHARGE SC Charging System
CHIME EL Warning Chime
CIGAR EL Cigarette Lighter
CLOCK EL Clock
COMPAS EL Compass and Thermometer
D/LOCK EL Power Door Lock
DEF EL Rear Window Defogger
DTRL EL Headlamp Ð With Daytime Light
System Ð
ECTS EC Engine Coolant Temperature Sen-
sor
ENGSS AT Engine Speed Signal
F/FOG EL Front Fog Lamp
F/LID EL Fuel Lid Opener
F/PUMP EC Fuel Pump Control
FICD EC IACV-FICD Solenoid Valve
FLS1 EC Fuel Gauge
Code Section Wiring Diagram Name
FLS2 EC Fuel Gauge
FLS3 EC Fuel Gauge
FTS AT A/T Fluid Temperature Sensor
FUELLH EC Fuel Injection System Function
(Left Bank)
FUELRH EC Fuel Injection System Function
(Right Bank)
H/AIM EL Headlamp Aiming Control System
H/LAMP EL Headlamp
HORN EL Horn
HSEAT EL Heated Seat
IATS EC Intake Air Temperature Sensor
IGN/SG EC Ignition Signal
ILL EL Illumination
INJECT EC Injector
INT/L EL Interior, Spot, Vanity Mirror, and
Luggage Room Lamps
IVC-L EC Intake Valve Timing Control Sole-
noid Valve LH
IVC-R EC Intake Valve Timing Control Sole-
noid Valve RH
IVCS EL INFINITI Communicator
IVCS-L EC Intake Valve Timing Control Posi-
tion Sensor LH
IVCS-R EC Intake Valve Timing Control Posi-
tion Sensor RH
KS EC Knock Sensor
LAN AT A/T Communication Line
LOAD EC Electrical Load Signal
LPSV AT Line Pressure Solenoid Valve
MAFS EC Mass Air Flow Sensor
MAIN AT Main Power Supply and Ground
Circuit
MAIN EC Main Power Supply and Ground
Circuit
METER EL Speedometer, Tachometer, Temp.,
Oil, and Fuel Gauges
MIL/DL EC MIL and Data Link Connectors
MIRROR EL Door Mirror
MULTI EL Multi-remote Control System
NATS EL IVIS (Infiniti Vehicle Immobiliser
System)
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WIRING DIAGRAM CODES (CELL CODES)
EL-457
Page 1700 of 2395
Removal and InstallationNBEM0042WARNING:
ISituate vehicle on a flat and solid surface.
IPlace chocks at front and back of rear wheels.
IDo not remove engine until exhaust system has com-
pletely cooled off. Otherwise, you may burn yourself
and/or fire may break out in fuel line.
IFor safety during subsequent steps, the tension of wires
should be slackened against the engine.
IBefore disconnecting fuel hose, release fuel pressure
from fuel line.
Refer to EC-39, ªFuel Pressure Releaseº.
IBefore removing front axle from transmission, place
safety stands under designated front supporting points.
Refer to GI section for lifting points and towing.
IBe sure to hoist engine and transmission in a safe man-
ner.
IFor engines not equipped with engine slingers, attach
proper slingers and bolts described in PARTS CATALOG.
CAUTION:
IWhen lifting engine, be careful not to strike adjacent parts,
especially accelerator wire casing, brake lines, and brake
master cylinder.
IIn hoisting the engine, always use engine slingers in a
safe manner.
IBefore separating engine and transmission, remove
crankshaft position sensor (POS) from the assembly.
IAlways take extra care not to damage edge of crankshaft
position sensor (POS), or ring gear teeth.GI
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ENGINE ASSEMBLY
Removal and Installation
EM-57
Page 1735 of 2395
SFE422A
6. Remove parking brake wire from fuel tank protector.
7. Remove fuel tank protector.
SFE469A
8. Remove fuel tank band mounting bolts while supporting fuel
tank.
9. Remove fuel tank.
Installation procedure is the reverse order of removal.
FUEL PUMP AND GAUGENBFE0004S02
SFE541A
1. Release fuel pressure from fuel line.
Refer to MA-16, ªChanging Fuel Filterº.
2. Remove inspection hole cover located behind the rear seat.
3. Disconnect harness connectors and fuel tubes from upper
plate of fuel gauge.
IPut mating marks on tubes for correct installation.
4. Remove fuel gauge retainer and fuel gauge.
FUEL SYSTEM
Removal and Installation (Cont'd)
FE-6
Page 1745 of 2395
QUICK REFERENCE CHART: QX42001
Engine model VQ35DE
Firing order 1-2-3-4-5-6
Idle speed rpmA/T
(in ªNº position)750 50
Ignition timing (degree BTDC at idle speed) 15É 2É
CO% at idleIdle mixture screw is preset and
sealed at factory.
Drive belt deflection (Cold) mm (in) Used belt
Deflection of
new belt
LimitDeflection
after
adjustment
Alternator
Power steering oil pump
Fan7 (0.28)4-5
(0.16 - 0.20)3.5 - 4.5
(0.138 - 0.177)
Air conditioner compressor 12 (0.472)9-10
(0.354 - 0.394)8-9
(0.31 - 0.35)
Applied pressed force
N (kg, lb)98 (10, 22)
Drive belt tension adjustment (Cold)
N (kg, lb)Used belt
New belt
LimitAfter
adjustment
Alternator
Power steering pump
Fan294 (30, 66)730 - 818
(74.4 - 83.5,
164 - 184)838 - 926
(85.4 - 94.5,
188 - 208)
Air conditioner compressor 196 (20, 44)348 - 436
(35.5 - 44.5,
78 - 98)470 - 559
(47.9 - 57.0,
106 - 126)
Radiator cap relief pressure
kPa (kg/cm
2, psi)78 - 98 (0.8 - 1.0, 11 - 14)
Cooling system leakage testing pressure
kPa (kg/cm
2, psi)157 (1.6, 23)
Compression pressure
kPa (kg/cm
2, psi)/rpmStandard 1,275 (13.0, 185)/300
Minimum 981 (10.0, 142)/300
Spark plugStandard PLFR5A-11
Cold PLFR6A-11
Hot PLFR4A-11
Applied model 245/70 R16 tire
Camber
Degree minute
(Decimal degree)Minimum þ0É35¢(þ0.58É)
Nominal 0É10¢(0.17É)
Maximum 0É55¢(0.92É)
Left and right
difference45¢(0.75É) or less
Caster
Degree minute
(Decimal degree)Minimum 2É15¢(2.25É)
Nominal 3É00¢(3.00É)
Maximum 3É45¢(3.75É)
Left and right
difference45¢(0.75É) or less
Total toe-in Minimum 1 (0.04)
Distance (A þ B)
mm (in)Nominal 2 (0.08)
Maximum 3 (0.12)
Angle (left plus right)
Degree minute
(Decimal degree)Minimum 5¢(0.08É)
Nominal 10¢(0.17É)
Maximum 15¢(0.25É)
Wheel turning angle
(Full turn)Minimum 30É00¢(30.00É)
Inside
Degree minute
(Decimal degree)Nominal 33É00¢(33.00É)
Maximum 34É00¢(34.00É)
Outside
Degree minute
(Decimal degree)Minimum 28É00¢(28.00É)
Nominal 31É00¢(31.00É)
Maximum 32É00¢(32.00É)
* Fuel, radiator coolant and engine oil full.
Spare tire, jack, hand tools and mats in designated positions.
Unit: mm (in)Front brake
Pad wear limit 2.0 (0.079)
Rotor repair limit 26.0 (1.024)
Rear brake
Lining wear limit 1.5 (0.059)
Drum repair limit 296.5 (11.67)
Pedal free height 175 - 185 (6.89 - 7.28)
Pedal depressed height*1 70 (2.76)
Parking brake
Number of notches*2 6 - 8
*1 Under force of 490 N (50 kg, 110 lb) with engine running
*2 At pulling force: 196 N (20 kg, 44 lb)
Unit Liter US measure
Coolant with reservoir 9.2 9-3/4 qt
Engine*With oil filter 5.0 5-1/4 qt
Without oil filter 4.8 5-1/8 qt
Dry engine (engine overhaul) 6.8 7-1/4 qt
Transmis-
sionA/T2WD
8.5 9 qt
4WD
All-mode 4WD transfer 3.0 2-5/8 qt
Differential carrierFront 1.85 3-7/8 pt
Rear 2.8 5-7/8 pt
Power steering system 0.9 1 qt
Air conditioning systemRefrigerant 0.60 - 0.70 kg 1.32 - 1.54 lb
Compressor
oil0.20 6.8 fl oz
* For further details, see ªChanging Engine Oilº in MA section.
Preload
(At hub bolt)
N (kg, lb)Wheel bearing lock nut
78-98(8-10,58-72)
Tightening torque
N×m (kg-m, ft-lb)
Retightening torque after loosen-
ing wheel bearing lock nut
N×m (kg-m, in-lb)0.5 - 1.5 (0.05 - 0.15, 4.3 - 13.0)
Axial end play
mm (in)0 (0)
Starting force at wheel hub bolt
N (kg, lb)A
Turning angle
degree15É - 30É
Starting force at wheel hub bolt
N (kg, lb)B
Wheel bearing preload at wheel hub
bolt
B þ A N (kg, lb)7.06 - 20.99 (0.72 - 2.14, 1.59 - 4.72)