air condition INFINITI QX4 2001 Factory Service Manual

8 CHECK HEADLAMP INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect headlamp LH relay.
4. Check harness continuity between ECM terminal 52 and headlamp LH relay terminal 7 under the following conditions.
SEF031Z
5. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 10.
NG©GO TO 9.
9 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1
IHarness connectors M33, F22
IDiode E121
IHarness for open and short between ECM and headlamp LH relay or daytime light control unit
©Repair open circuit or short to ground or short to power in harness or connectors.
10 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
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ELECTRICAL LOAD SIGNAL
Diagnostic Procedure (Cont'd)
EC-647

Fuel Pressure RegulatorNBEC0408
Fuel pressure at idling kPa (kg/cm2, psi)
Vacuum hose is connected. Approximately 235 (2.4, 34)
Vacuum hose is disconnected. Approximately 294 (3.0, 43)
Idle Speed and Ignition TimingNBEC0409
Target idle speed*1 No-load*2 (in ªPº or Nº position) 750±50 rpm
Air conditioner: ON In ªPº or Nº position 825 rpm or more
Ignition timing*1 In ªPº or Nº position 15ɱ5É BTDC
Throttle position sensor idle position0.15 - 0.85V
*1: Throttle position sensor harness connector connected
*2: Under the following conditions:
IAir conditioner switch: OFF
IElectric load: OFF (Lights, heater fan & rear window defogger)
ISteering wheel: Kept in straight-ahead position
Mass Air Flow SensorNBEC0411
Supply voltageBattery voltage (11 - 14)V
Output voltage at idle1.2 - 1.8*V
Mass air flow (Using CONSULT-II or GST)2.0 - 6.0 g´m/sec at idle*
7.0 - 20.0 g´m/sec at 2,500 rpm*
*: Engine is warmed up to normal operating temperature and running under no-load.
Engine Coolant Temperature SensorNBEC0412
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Heated Oxygen Sensor 1 Heater (Front)NBEC0414
Resistance [at 25ÉC (77ÉF)]2.3 - 4.3W
Fuel PumpNBEC0415
Resistance [at 25ÉC (77ÉF)]0.2 - 5.0W
IACV-AAC ValveNBEC0416
Resistance [at 20ÉC (68ÉF)]Approximately 20 - 24W
InjectorNBEC0417
Resistance [at 20ÉC (68ÉF)]13.5 - 17.5W
ResistorNBEC0418
Resistance [at 25ÉC (77ÉF)]Approximately 2.2 kW
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SERVICE DATA AND SPECIFICATIONS (SDS)
Fuel Pressure Regulator
EC-649

Throttle Position SensorNBEC0419
Throttle valve conditionsVoltage
(at normal operating temperature,
engine off, ignition switch ON,
throttle opener disengaged)
Completely closed (a)0.15 - 0.85V
Partially openBetween (a) and (b)
Completely open (b)3.5 - 4.7V
Calculated Load ValueNBEC0420
Calculated load value % (Using CONSULT-II or GST)
At idle14.0 - 33.0
At 2,500 rpm12.0 - 25.0
Intake Air Temperature SensorNBEC0421
Temperature ÉC (ÉF) Resistance kW
20 (68)2.1 - 2.9
80 (176)0.27 - 0.38
Heated Oxygen Sensor 2 Heater (Rear)NBEC0422
Resistance [at 25ÉC (77ÉF)]2.3 - 4.3W
Crankshaft Position Sensor (REF)NBEC0423
Resistance [at 20ÉC (68ÉF)]470 - 570W
Fuel Tank Temperature SensorNBEC0424
Temperature ÉC (ÉF) Resistance kW
20 (68)2.3 - 2.7
50 (122)0.79 - 0.90
Camshaft Position Sensor (PHASE)NBEC0639
Resistance [at 20ÉC (68ÉF)]HITACHI make 1,440 - 1,760W
MITSUBISHI make 2,090 - 2,550W
SERVICE DATA AND SPECIFICATIONS (SDS)
Throttle Position Sensor
EC-650

Schematic ................................................................255
Wiring Diagram - D/LOCK -.....................................256
Trouble Diagnoses...................................................261
MULTI-REMOTE CONTROL SYSTEM.......................270
Component Parts and Harness Connector
Location ...................................................................270
System Description ..................................................270
Schematic ................................................................273
Wiring Diagram - MULTI - .......................................274
Trouble Diagnoses...................................................277
ID Code Entry Procedure ........................................289
Remote Controller Battery Replacement.................293
THEFT WARNING SYSTEM.......................................294
Component Parts and Harness Connector
Location ...................................................................294
System Description ..................................................295
Schematic ................................................................298
Wiring Diagram - THEFT -.......................................300
Trouble Diagnoses...................................................306
SMART ENTRANCE CONTROL UNIT.......................319
Description ...............................................................319
Schematic ................................................................322
Smart Entrance Control Unit Inspection Table ........324
INTEGRATED HOMELINK TRANSMITTER...............325
Wiring Diagram - TRNSMT - ...................................325
Trouble Diagnoses...................................................326
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM -
NATS)...........................................................................328
Component Parts and Harness Connetor
Location ...................................................................328
System Description ..................................................329
System Composition ................................................329
Wiring Diagram - NATS -.........................................330
CONSULT-II .............................................................331
Trouble Diagnoses...................................................334
How to Replace IVIS (NATS) IMMU .......................347
INFINITI COMMUNICATOR (IVCS)............................348
Precaution ................................................................348
Communicator Response Center Telephone
Number for Technicians ...........................................348
Component Parts and Harness Connector
Location ...................................................................349System Description ..................................................350
Schematic ................................................................358
Wiring Diagram - IVCS -..........................................359
CONSULT-II .............................................................363
Trouble Diagnoses...................................................368
Trouble Diagnoses for Intermittent Incident ............377
Demonstration Mode ...............................................379
System Setting (When IVCS Unit is Replaced) ......381
NAVIGATION SYSTEM...............................................385
Component Parts Location ......................................385
System Description ..................................................386
Schematic ................................................................393
Wiring Diagram - NAVI - ..........................................394
Self-diagnosis Mode ................................................397
Confirmation/Adjustment Mode ...............................400
Setting Mode............................................................410
Trouble diagnoses ...................................................417
This Condition is Not Abnormal ...............................423
Program Loading .....................................................432
Initialization ..............................................................433
ELECTRICAL UNITS LOCATION...............................436
Engine Compartment ...............................................436
Passenger Compartment .........................................438
HARNESS LAYOUT....................................................440
How to Read Harness Layout .................................440
Outline......................................................................441
Main Harness...........................................................442
Engine Room Harness ............................................444
Engine Control Harness ..........................................446
Body Harness LH ....................................................448
Body Harness RH ....................................................449
Back Door Harness .................................................450
Engine and Transmission Harness..........................451
Room Lamp Harness...............................................452
Air Bag Harness ......................................................453
Front Door Harness .................................................454
Rear Door Harness..................................................455
BULB SPECIFICATIONS............................................456
Headlamp.................................................................456
Exterior Lamp ..........................................................456
Interior Lamp............................................................456
WIRING DIAGRAM CODES (CELL CODES).............457GI
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CONTENTS(Cont'd)
EL-3

System DescriptionNBEL0153
SEL713U
This unit displays following items:
IEarth magnetism and heading direction of vehicle.
IOutside air temperature.
ICaution for frozen road surfaces.
OUTSIDE TEMPERATURE DISPLAYNBEL0153S01Push the switch when the ignition key is in the ªACCº or ªONº position. The outside temperature will be dis-
played in ªÉFº.
ISelecting the indication range
Push the switch to change from ªÉFº to ªÉCº.
IWhen the outside temperature drops below freezing point, ICE is displayed on the unit.
IWhen the outside temperature is between 55ÉC (130ÉF) and 70ÉC (158ÉF), the display shows 55ÉC
(130ÉF).
IWhen the outside temperature is lower than þ30ÉC (þ20ÉF) or higher than 70ÉC (158ÉF), the display shows
only ª---º though it is operating. This is not a problem.
IThe indicated temperature on the thermometer is not readily affected by engine heat. It changes only when
one of the following conditions is present.
a) The temperature detected by the ambient air temperature sensor is lower than the indicated temperature
on the thermometer.
b) The difference in temperature detected during a period of 40 seconds is less than 1ÉC (1.8ÉF) when vehicle
speed has been greater than 24 km/h (15 MPH) for more than 100 seconds.
(This is to prevent the indicated temperature from being affected by engine heat or cooling fan operation
during low-speed driving.)
c) The ignition key has been turned to the ªOFFº position for more than 4 hours. (The engine is cold.)
DIRECTION DISPLAYNBEL0153S02Push the switch when the ignition key is in the ªACCº or ªONº position. The direction will be displayed.
COMPASS AND THERMOMETER
System Description
EL-110

Trouble DiagnosesNBEL0048PRELIMINARY CHECK FOR THERMOMETERNBEL0048S02
1 COOL DOWN CHECK
1. Turn the ignition key switch to the ªACCº position.
2. Cool down the ambient air temperature sensor with water or ice, so that the indicated temperature falls.
Does the indicated temperature fall?
Ye s©GO TO 2.
No©The system is malfunctioning. Check the system following ªINSPECTION/COMPASS
AND THERMOMETERº.
2 WARM UP CHECK
1. Leave the vehicle for 10 minutes, so that the indicated temperature rises.
2. With the ignition key in the ªACCº position, disconnect and reconnect the ambient air temperature sensor connector.
Does the indicated temperature rise?
Ye s©The system is OK.
No©The system is malfunctioning. Check the system following ªINSPECTION/COMPASS
AND THERMOMETERº.
NOTE:
IWhen the outside temperature is between 55ÉC (130ÉF) and 70ÉC (158ÉF), the display shows 55ÉC
(130ÉF). When the outside temperature is lower than þ30ÉC (þ20ÉF) or higher than 70ÉC (158ÉF), the dis-
play shows only ª---º.
IThe indicated temperature on the thermometer is not readily affected by engine heat. It changes only when
one of the following conditions is present.
a) The temperature detected by the ambient air temperature sensor is lower than the indicated temperature
on the thermometer.
b) The difference in temperature detected during a period of 40 seconds is less than 1ÉC (1.8ÉF) when vehicle
speed has been greater than 24 km/h (15 MPH) for more than 100 seconds.
(This is to prevent the indicated temperature from being affected by engine heat or cooling fan operation
during low-speed driving.)
c) The ignition key has been turned to the ªOFFº position for more than 4 hours. (The engine is cold.)
INSPECTION/COMPASS AND THERMOMETERNBEL0048S01
Symptom Possible causes Repair order
No display at all 1. 10A fuse
2. Ground circuit
3. Compass and thermometer1. Check 10A fuse [No. 9, located in fuse block (J/B)].
Turn the ignition switch ON and verify that battery positive
voltage is at terminal 7 of compass and thermometer.
2. Check ground circuit for compass and thermometer.
3. Replace compass and thermometer.
Forward direction indi-
cation slips off the
mark or incorrect.1. In manual correction mode (Bar
and display vanish.)
2. Zone variation change is not done.1. Drive the vehicle and turn at an angle of 90É.
2. Perform the zone variation change.
Compass reading
remains unchanged.1. Vehicle speed sensor is not
entered.
2. Compass and thermometer1. Check harness for open or short between combination meter
terminal 13 and compass and thermometer terminal 1.
2. Replace compass and thermometer.
Displays wrong tem-
perature when ambient
temperature is between
þ30ÉC (þ20ÉF) and
55ÉC (130ÉF). (See
NOTE above.)1. Check operation
2. Ambient air temperature sensor
circuit
3. Vehicle speed sensor is not
entered.
4. Ambient air temperature sensor
5. Compass and thermometer1. Perform preliminary check shown above.
2. Check harness for open or short between ambient air tem-
perature sensor and compass and thermometer.
3. Check harness for open or short between combination meter
terminal 13 and compass and thermometer terminal 1.
4. Replace ambient air temperature sensor.
5. Replace compass and thermometer.
COMPASS AND THERMOMETER
Trouble Diagnoses
EL-112

5 CHECK SMART ENTRANCE CONTROL UNIT GROUND CIRCUIT
Check continuity between smart entrance control unit terminal 16 and ground.
SEL388X
OK or NG
OK©Replace smart entrance control unit.
NG©Repair harness or connectors.
SEC202B
Electrical Components InspectionNBEL0076REAR WINDOW DEFOGGER RELAYNBEL0076S01Check continuity between terminals 3 and 5, 6 and 7.
Condition Continuity
12V direct current supply between ter-
minals 1 and 2Ye s
No current supply No
SEL430TB
REAR WINDOW DEFOGGER SWITCHNBEL0076S02Check continuity between terminals when rear window defogger
switch is pushed and released.
Terminals Condition Continuity
1-2Rear window defogger
switch is pushedYe s
Rear window defogger
switch is releasedNo
SEL263
Filament CheckNBEL00771. Attach probe circuit tester (in volt range) to middle portion of
each filament.
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REAR WINDOW DEFOGGER
Trouble Diagnoses (Cont'd)
EL-157

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

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

2 CHECK ASCD PUMP CIRCUIT
1. Disconnect ASCD control unit harness connector.
2. Check harness for open or short between ASCD control unit and ASCD pump.
SEL269WB
OK or NG
OK©GO TO 3.
NG©Repair harness.
3 CHECK ASCD PUMP POWER SUPPLY
1. Jack-up the drive wheels.
2. Maintain the conditions below.
IVehicle speed is more than 40 km/h (25 MPH).
IMain switch (CRUISE lamp) is ON.
ISet/coast switch (SET lamp) is ON.
Check voltage between ASCD control unit harness connector terminal 12 and ground.
SEL381WB
OK or NG
OK©ASCD pump power supply is OK.
NG©Replace ASCD control unit.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Trouble Diagnoses (Cont'd)
EL-236