sensor INFINITI QX56 2004 Factory Service Manual

DI-22
COMBINATION METERS
Revision: August 20072004 QX56
Fuel Level Sensor Unit InspectionEKS007DZ
FUEL LEVEL SENSOR UNIT
The following symptoms do not indicate a malfunction.

Depending on vehicle position or driving circumstance, the fuel in the tank shifts and the indication may
fluctuate.

If the vehicle is fueled with the ignition switch ON, the indication will update slowly.

If the vehicle is tilted when the ignition switch is turned ON, fuel in the tank may flow to one direction
resulting in a change of reading.
LOW-FUEL WARNING LAMP
Depending on vehicle posture or driving circumstances, the fuel level in the tank varies, and the warning lamp
ON timing may be changed.
1. CHECK SELF-DIAGNOSIS
Perform the combination meter self-diagnosis. Refer to DI-13, "
SELF-DIAGNOSIS FUNCTION" .
OK or NG
OK >> GO TO 2.
NG >> Replace the combination meter. Refer to IP-13, "
Combination Meter" .
2. CHECK HARNESS CONNECTOR
1. Turn the ignition switch OFF.
2. Check combination meter and fuel level sensor unit and fuel pump terminals (meter-side, and harness-
side) for poor connection.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace terminals or connectors.
3. CHECK HARNESS CONNECTOR OUTPUT SIGNAL
1. Disconnect fuel level sensor unit and fuel pump connector.
2. Turn ignition switch ON.
3. Check voltage between combination meter harness connector
M24 terminal 15 (Y/L) and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" . Battery voltageWKIA1816E

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4. CHECK HARNESS FOR OPEN OR SHORT CIRCUIT
1. Turn the ignition switch OFF.
2. Disconnect combination meter connector M24.
3. Check continuity between combination meter harness connector
M24 terminal 15 (Y/L) and fuel level sensor unit and fuel pump
harness connector C5 terminal 2 (Y/L).
4. Check continuity between fuel level sensor unit and fuel pump
harness connector C5 terminal 2 (Y/L) and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5. CHECK FUEL LEVEL SENSOR CIRCUIT
1. Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and fuel level sensor unit and fuel pump
harness connector C5 terminal 5 (B/P).
2. Check continuity between fuel level sensor unit and fuel pump
harness connector C5 terminal 5 (B/P) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK FUEL LEVEL SENSOR UNIT
Check the fuel level sensor unit. Refer to DI-25, "
FUEL LEVEL SENSOR UNIT CHECK" .
OK or NG
OK >> GO TO 7.
NG >> Replace the fuel level sensor unit. Refer to FL-5, "
Removal and Installation" .
7. CHECK INSTALLATION CONDITION
Check fuel level sensor unit installation, and determine whether the float arm interferes or binds with any of the
internal components in the fuel tank.
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combination Meter" .
NG >> Install the fuel level sensor unit properly.Continuity should exist.
Continuity should not exist.
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Continuity should exist.
Continuity should not exist.
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DI-24
COMBINATION METERS
Revision: August 20072004 QX56
Fuel Gauge Fluctuates, Indicates Wrong Value, or VariesEKS007E0
1. CHECK FUEL GAUGE FLUCTUATION
Test drive vehicle to see if gauge fluctuates only during driving or just before or just after stopping.
Does the indication value vary only during driving or just before or just after stopping?
YES >> The fluctuation may be caused by fuel level change in the fuel tank. Condition is normal.
NO >> Ask the customer about the situation when the symptom occurs in detail, Refer to DI-22, "
Fuel
Level Sensor Unit Inspection" .
Fuel Gauge Does Not Move to Full-positionEKS007E1
1. CHECK POINTER MOVEMENT TO FULL-POSITION
Does it take a long time for the pointer to move to full-position?
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. CHECK IGNITION SWITCH POSITION
Was the vehicle fueled with the ignition switch ON?
YES or NO
YES >> Be sure to fuel the vehicle with the ignition switch OFF. Otherwise, it will take a long time for the
pointer to move to full-position because of the characteristic of the fuel gauge.
NO >> GO TO 3.
3. OBSERVE VEHICLE POSITION
Is the vehicle parked on an incline?
YES or NO
YES >> Check the fuel level indication with vehicle on a level surface.
NO >> GO TO 4.
4. CHECK POINTER MOVEMENT TO EMPTY-POSITION
During driving, does the fuel gauge move gradually toward empty-position?
YES or NO
YES >> Check the fuel level sensor unit. Refer to DI-25, "FUEL LEVEL SENSOR UNIT CHECK" .
NO >> Check fuel level sensor unit installation, and determine whether the float arm interferes or binds
with any of the internal components in the fuel tank.

COMBINATION METERS
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Electrical Components InspectionEKS007E2
FUEL LEVEL SENSOR UNIT CHECK
For removal, refer to FL-5, "Removal and Installation" .
Check Fuel Level Sensor Unit and Fuel Pump
Check resistance between fuel level sensor unit and fuel pump con-
nector terminals 2 and 5.
*1 and *2: When float rod is in contact with stopper.
Removal and Installation of Combination MeterEKS007E3
Refer to IP-13, "Combination Meter" for removal and installation procedures.
Terminals Float position mm (in)Resistance
value Ω
(Approx.)
25*1 Empty 25.86 (1.02) 81.66
*2 Full 254.6 (10.02) 6.98
LKIA0402E

DI-26
COMPASS AND THERMOMETER
Revision: August 20072004 QX56
COMPASS AND THERMOMETERPFP:24835
System DescriptionEKS007E4
This unit displays the following items:

Earth magnetism and heading direction of vehicle.

Outside air temperature.

Caution for frozen road surfaces.
OUTSIDE TEMPERATURE DISPLAY
Push the mode switch when the ignition switch is in the ON position. The outside temperature will be displayed
in “°F”.

Selecting the indication range
Push the mode switch to change from °F → °C → OFF → °F.

The indicated temperature on the thermometer is not readily affected by engine heat. It changes only
when one of the following conditions is present.
–The temperature detected by the ambient sensor is lower than the indicated temperature on the thermom-
eter.
–The vehicle speed is greater than 20 km/h (13 MPH).
(This is to prevent the indicated temperature from being affected by engine heat during low-speed driv-
ing.)
–The ignition switch has been turned to the OFF position for more than 2 hours. (The engine is cold.)
DIRECTION DISPLAY
Push the mode switch when the ignition switch is in the ON position. The direction will be displayed.
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DI-28
COMPASS AND THERMOMETER
Revision: August 20072004 QX56
Trouble DiagnosesEKS007E6
PRELIMINARY CHECK FOR THERMOMETER
1. COOL DOWN CHECK
1. Turn the ignition switch to the ON position.
2. Cool down the ambient sensor with water or ice.
Does the indicated temperature drop?
Yes >> GO TO 2.
No >> The system is malfunctioning. Refer to DI-28, "
INSPECTION/COMPASS AND THERMOMETER"
.
2. WARM UP CHECK
1. Leave the vehicle for 10 minutes.
2. With the ignition switch in the ON position, disconnect and reconnect the ambient sensor connector.
Does the indicated temperature rise?
Yes >> The system is OK.
No >> The system is malfunctioning. Refer to DI-28, "
INSPECTION/COMPASS AND THERMOMETER"
.
NOTE:

The indicated temperature on the thermometer is not readily affected by engine heat. It changes only
when one of the following conditions is present.
–The temperature detected by the ambient sensor is lower than the indicated temperature on the thermom-
eter.
–The vehicle speed is greater than 20 km/h (13 MPH).
(This is to prevent the indicated temperature from being affected by engine heat during low-speed driv-
ing.)
–The ignition switch has been turned to the OFF position for more than 2 hours. (The engine is cold.)
INSPECTION/COMPASS AND THERMOMETER
Symptom Possible causes Repair order
No display at all 1. 10A fuse
2. Ground circuit
3. Compass and thermometer1. Check 10A fuse [No. 12, located in fuse block (J/B)].
Turn the ignition switch ON and verify that battery positive volt-
age is at terminal 2 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 90°.
2. Perform the zone variation change.
Compass reading
remains unchanged.1. Vehicle speed signal is not entered.
2. Compass and thermometer1. Check harness for open or short between combination meter
terminal 29 and compass and thermometer terminal 8.
2. Replace compass and thermometer.
Displays wrong tem-
perature when ambient
temperature is between
−40°C (−40°F) and
55°C (130°F). (See
NOTE above.)1. Check operation
2. Ambient sensor circuit
3. Vehicle speed signal is not entered.
4. Ambient sensor
5. Compass and thermometer1. Perform preliminary check shown above.
2. Check harness for open or short between ambient sensor and
compass and thermometer.
3. Check harness for open or short between combination meter
terminal 29 and compass and thermometer terminal 8.
4. Replace ambient sensor.
5. Replace compass and thermometer.
Displays SC or OC. 1. Ambient sensor circuit.
2. Ambient sensor.
3. Compass and thermometer.1. Check harness for open or short between ambient sensor and
compass and thermometer.
2. Replace ambient sensor.
3. Replace compass and thermometer.

DI-38
WARNING LAMPS
Revision: August 20072004 QX56
Oil Pressure Warning Lamp Stays Off (Ignition Switch ON)EKS007EA
1. CHECK OIL PRESSURE SENSOR SIGNAL
1. Turn ignition switch ON.
2. Check voltage between combination meter harness connector
M24 terminal 20 (Y) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK OIL PRESSURE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect combination meter connector M24 and oil pressure
sensor connector F4.
3. Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and oil pressure sensor harness connec-
tor F4 terminal 3 (B/P).
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combi-
nation Meter" .
NG >> Repair harness or connector.
3. CHECK OIL PRESSURE SENSOR REFERENCE VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect oil pressure sensor connector F4.
3. Turn ignition switch ON.
4. Check voltage between combination meter harness connector
M24 terminal 22 (GR/L) and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
Terminals
Condition Voltage (V) (+)
(–)
ConnectorTe r m i n a l
(Wire color)
M24 20 (Y) GroundWhen ignition switch is in ON
position. (Engine stopped)Ye s
Engine running. (Idle speed) Yes
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Continuity should exist.
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Voltage : Approx. 5V
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4. CHECK OIL PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect combination meter connector M24.
3. Check continuity between combination meter harness connector M24 terminal 22 (GR/L) and oil pressure
sensor harness connector F4 terminal 1 (GR/L).
4. Check continuity between combination meter harness connector
M24 terminal 22 (GR/L) and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5. CHECK OIL PRESSURE SENSOR SIGNAL CIRCUIT
1. Check continuity between combination meter harness connector M24 terminal 20 (Y) and oil pressure
sensor harness connector F4 terminal 2 (Y).
2. Check continuity between combination meter harness connector
M24 terminal 20 (Y) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK OIL PRESSURE SENSOR GROUND CIRCUIT
Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and ground.
OK or NG
OK >> Replace oil pressure sensor.
NG >> Repair harness or connector.Continuity should exist.
Continuity should not exist.
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Continuity should exist.
Continuity should not exist.
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Continuity should not exist.
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DI-60
REAR SONAR SYSTEM
Revision: August 20072004 QX56
System DescriptionEKS007ET
FUNCTION
With the ignition switch in the ON or START position, power is supplied

through 10A fuse [No. 12 , located in the fuse block (J/B)]

to sonar control unit terminal 8, and

through 10A fuse [No. 51, located in the IPDM E/R]

to back-up lamp relay terminals 1 and 3.
Ground is supplied

to sonar control unit terminal 6

through body grounds B7 and B19.
With the ignition switch in the ON or START position, and the transmission gear selector lever in the R posi-
tion, power is supplied

to sonar control unit terminal 5

from back-up lamp relay terminal 5.
With power and ground supplied, transmission gear selector lever in R position, and the rear sonar system
OFF switch ON, the rear sonar system will detect obstacles within 1.8 m (5.9 ft.) of the rear sonar sensors.
The vehicle operator is notified of obstacles by varied rate of tone from the sonar buzzer depending on dis-
tance of obstacle being sensed.
REAR SONAR SYSTEM OFF SWITCH
With power and ground supplied to the sonar control unit, transmission gear selector lever in R position, the
sonar system can be disabled and the sonar buzzer silenced by momentarily pressing the rear sonar system
OFF switch. The rear sonar system OFF indicator lamp will be illuminated in the rear sonar system OFF
switch.
To disable the rear sonar system, ground is supplied

to sonar control unit terminal 13

through rear sonar system OFF switch terminal 1

through rear sonar system OFF switch terminal 2

from body grounds M57, M61, and M79.
To light the rear sonar system OFF indicator, power is supplied

to the rear sonar system OFF switch terminal 5

from sonar control unit terminal 4.
Ground is supplied

to the rear sonar system OFF switch terminal 6

from body grounds M57, M61, and M79.
The rear sonar system and buzzer will be disabled and the rear sonar system OFF indicator will be illuminated
until the ignition switch is turned OFF. When the ignition switch is turned ON, the rear sonar system will be
enabled. Depressing the rear sonar system OFF switch momentarily will enable the rear sonar system also.
Enabling the rear sonar system will cause the rear sonar system OFF indicator to go out.
SONAR BUZZER
With power supplied to the sonar control unit and the transmission gear selector lever in R position, a station-
ary object that is at least 7.0 cm (2.8 in.) wide and 1.0 m (39.0 in.) tall and that is closer than 1.8 meters (5.9 ft.)
will be detected by the rear sonar sensors, causing the sonar buzzer to sound a tone. As the vehicle moves
closer to the object, the rate of the tone will increase. When the object is less than 25.0 cm (10 in.) from the
rear bumper, the tone will sound continuously.
Power is supplied

to sonar buzzer terminal +

from sonar control unit terminal 7.
Ground is supplied

to sonar buzzer terminal -

from sonar control unit terminal 3.

REAR SONAR SYSTEM
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REAR SONAR SENSOR
With power and ground supplied to the rear sonar sensors, the sonar sensors transmit a 38.4 kHz ultrasonic
signal. This signal is reflected back to the sensor by objects large enough and close enough to be detected.
The rear sonar sensors measure the time from the transmitted signal to the time the signal is reflected back
and sends this information to the sonar control unit.
Power is supplied

to each rear sonar sensor terminal 1

from sonar control unit terminal 16.
Ground is supplied

to each rear sonar sensor terminal 3

from sonar control unit terminal 15.
Signal is supplied

to sonar control unit terminals 9, 10, 11 and 12.

from each rear sonar sensor terminal 2