02 sensor INFINITI QX4 2001 Factory Service Manual

POWER SUPPLY AND GROUND CIRCUITNBEL0042S08Power is supplied at all times
Ithrough 7.5A fuse [No. 24, located in the fuse block (J/B)]
Ito combination meter terminal 62.
With the ignition switch in the ON or START position, power is supplied
Ithrough 10A fuse [No. 8, located in the fuse block (J/B)]
Ito combination meter terminal 66.
Ground is supplied
Ito combination meter terminal 59
Ithrough body grounds M4, M66 and M147.
WATER TEMPERATURE GAUGENBEL0042S01The water temperature gauge indicates the engine coolant temperature. The reading on the gauge is based
on the resistance of the thermal transmitter.
As the temperature of the coolant increases, the resistance of the thermal transmitter decreases. A variable
ground is supplied to terminal 18 of the combination meter for the water temperature gauge. The needle on
the gauge moves from ªCº to ªHº.
TACHOMETERNBEL0042S02The tachometer indicates engine speed in revolutions per minute (rpm).
The tachometer is regulated by a signal
Ifrom terminal 25 of the ECM
Ito combination meter terminal 16 for the tachometer.
FUEL GAUGENBEL0042S03The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by a variable ground signal supplied
Ito combination meter terminal 17 for the fuel gauge
Ifrom terminal 3 of the fuel level sensor unit
Ithrough terminal 2 of the fuel level sensor unit and
Ithrough body grounds B11, B22 and D210.
SPEEDOMETERNBEL0042S04The vehicle speed sensor provides a voltage signal to the combination meter for the speedometer.
The voltage is supplied
Ifrom combination meter terminal 15 for the speedometer
Ito terminal 2 of the vehicle speed sensor.
The speedometer converts the voltage into the vehicle speed displayed.
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
IDX
METERS AND GAUGES
System Description (Cont'd)
EL-95

SYMPTOM CHARTNBEL0201S02Symptom Chart 1 (Malfunction is Indicated in
Diagnosis Mode)
NBEL0201S0201
Symptom Possible causes Repair order
Odo/trip meter indicate(s)
malfunction in Diagnosis
mode.Unified meter control unit Replace unified meter control unit.
Multiple meter/gauge indi-
cate malfunction in Diagno-
sis mode.
One of speedometer/
tachometer/fuel gauge/
water temp. gauge indi-
cates malfunction in Diag-
nosis mode.1. Meter/Gauge
2. Unified meter control unit1. Check resistance of meter/gauge indicating malfunc-
tion. If the resistance is NG, replace the meter/
gauge. Refer to ªMETER/GAUGE RESISTANCE
CHECKº, EL-108.
2. If the resistance of meter/gauge is OK, replace uni-
fied meter control unit.
Symptom Chart 2 (No Malfunction is Indicated in
Diagnosis Mode)
NBEL0201S0202
Symptom Possible causes Repair order
One of speedometer/
tachometer/fuel gauge/
water temp. gauge is mal-
functioning.1. Sensor signal
- Vehicle speed signal
- Engine revolution signal
- Fuel gauge
- Water temp. gauge
2. Unified meter control unit1. Check the sensor for malfunctioning meter/gauge.
INSPECTION/VEHICLE SPEED SENSOR (Refer to
EL-104.)
INSPECTION/ENGINE REVOLUTION SIGNAL
(Refer to EL-105.)
INSPECTION/FUEL LEVEL SENSOR UNIT (Refer to
EL-106.)
INSPECTION/THERMAL TRANSMITTER (Refer to
EL-107.)
2. Replace unified meter control unit. Multiple meter/gauge are
malfunctioning. (except
odo/trip meter)
Before starting trouble diagnoses below, perform PRELIMINARY
CHECK, EL-101.
METERS AND GAUGES
Trouble Diagnoses (Cont'd)
EL-102

INSPECTION/VEHICLE SPEED SENSOR=NBEL0201S04
1 CHECK VEHICLE SPEED SENSOR OUTPUT
1. Remove vehicle speed sensor from transmission.
2. Check voltage between combination meter terminals 15 and 63 while quickly turning speed sensor pinion.
SEL297X
OK or NG
OK©Vehicle speed sensor is OK.
NG©GO TO 2.
2 CHECK VEHICLE SPEED SENSOR
Check resistance between vehicle speed sensor terminals 1 and 2.
SEL298X
OK or NG
OK©Check harness or connector between speedometer and vehicle speed sensor.
NG©Replace vehicle speed sensor.
METERS AND GAUGES
Trouble Diagnoses (Cont'd)
EL-104

INSPECTION/FUEL LEVEL SENSOR UNIT=NBEL0201S06
1 CHECK GROUND CIRCUIT FOR FUEL LEVEL SENSOR UNIT
Check harness continuity between fuel level sensor unit terminal 2 and ground.
SEL299X
OK or NG
OK©GO TO 2.
NG©Repair harness or connector.
2 CHECK FUEL LEVEL SENSOR UNIT
Refer to ªFUEL LEVEL SENSOR UNIT CHECKº (EL-108).
OK or NG
OK©GO TO 3.
NG©Replace fuel level sensor unit.
3 CHECK HARNESS FOR OPEN OR SHORT
1. Disconnect combination meter connector and fuel level sensor unit connector.
2. Check continuity between combination meter terminal 17 and fuel level sensor unit terminal 3.
3. Check continuity between combination meter terminal 17 and ground.
SEL300X
OK or NG
OK©Fuel level sensor unit is OK.
NG©Repair harness or connector.
METERS AND GAUGES
Trouble Diagnoses (Cont'd)
EL-106

Electrical Components Inspection=NBEL0202METER/GAUGE RESISTANCE CHECKNBEL0202S01Check resistance between installation screws of meter/gauge.
Screws
Resistance
W
Tacho/Speedometer Fuel/Temp. gauge
A - C A - C Approx. 190 - Approx. 260
B - D B - C Approx. 230 - Approx. 310
SEL352X
YEL066K
FUEL LEVEL SENSOR UNIT CHECKNBEL0202S02IFor removal, refer to FE-4, ªFUEL SYSTEMº.
Check the resistance between terminals 3 and 2.
Ohmmeter
Float position mm (in)Resistance
valueW
(+) (þ)
32*1 Full 95 (3.74) Approx.4-6
*2 1/2 184 (7.24) 31 - 34
*3 Empty 265 (10.43) 80 - 83
*1 and *3: When float rod is in contact with stopper.
MEL424F
THERMAL TRANSMITTER CHECKNBEL0202S03Check the resistance between the terminals of thermal transmitter
and body ground.
Water temperature Resistance
60ÉC (140ÉF) Approx. 170 - 210W
100ÉC (212ÉF) Approx. 47 - 53W
METERS AND GAUGES
Electrical Components Inspection
EL-108

MEL005H
VEHICLE SPEED SENSOR SIGNAL CHECKNBEL0202S041. Remove vehicle speed sensor from transmission.
2. Turn vehicle speed sensor pinion quickly and measure voltage
across a and b.
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
IDX
METERS AND GAUGES
Electrical Components Inspection (Cont'd)
EL-109

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

SEL062WA
Fuel Warning Lamp Sensor CheckNBEL01661. Turn ignition switch ªOFFº.
2. Disconnect fuel level sensor unit harness connector B12.
3. Connect a resistor (80W) between fuel tank gauge unit harness
connector terminals 2 and 3.
4. Turn ignition switch ªONº.
The fuel warning lamp should come on.
NOTE:
ECM might store the 1st trip DTC P0180 during this inspection.
If the DTC is stored in ECM memory, erase the DTC after recon-
necting fuel tank gauge unit harness connector.
Refer to EC-60, ªHOW TO ERASE EMISSION-RELATED DIAG-
NOSTIC INFORMATIONº.
MEL425F
Electrical Components InspectionNBEL0051OIL PRESSURE SWITCH CHECKNBEL0051S02
Oil pressure
kPa (kg/cm2, psi)Continuity
Engine startMore than 10 - 20
(0.1-0.2,1-3)NO
Engine stopLess than 10 - 20
(0.1-0.2,1-3)YES
Check the continuity between the terminals of oil pressure switch
and body ground.
SEL901F
DIODE CHECKNBEL0051S03ICheck continuity using an ohmmeter.
IDiode is functioning properly if test results are as shown in the
figure at left.
ICheck diodes at the combination meter harness connector
instead of checking them on the combination meter assembly.
Refer to EL-115, ªWARNING LAMPº wiring diagrams.
NOTE:
Specification may vary depending on the type of tester. Before
performing this inspection, be sure to refer to the instruction
manual for the tester to be used.
WARNING LAMPS
Fuel Warning Lamp Sensor Check
EL-122

On Board DiagnosisNBEL0213
SEL354X
HOW TO PERFORM SELF-DIAGNOSISNBEL0213S01
SEL596W
*1: If no malfunction is indicated, self-diagnosis will end after the vehicle speed sensor diagnosis is performed.
*2: Diagnosis ends after self-diagnostic results have been indicated for 10 minutes if left unattended.
AUTOMATIC DRIVE POSITIONER
On Board Diagnosis
EL-196