air condition INFINITI QX56 2004 Factory Service Manual

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-53
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
4. REAR PRESSURE SENSOR INSPECTION
1. Reconnect the rear pressure sensor and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "PRESS SEN 2" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace rear pressure sensor.
Steering Angle Sensor Safe Mode InspectionEFS0062X
INSPECTION PROCEDURE
1. INDICATOR LAMP CHECK
Check that VDC OFF indicator lamp is on.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION
Adjust steering angle sensor neutral position. Refer to BRC-62, "
Adjustment of Steering Angle Sensor Neutral
Position" .
OK or NG
OK >> GO TO 3.
NG >> Check steering angle sensor. Refer to BRC-40, "
Steering Angle Sensor System" .
3. INDICATOR LAMP CHECK
Check that VDC OFF indicator lamp is off.
OK or NG
OK >> GO TO 4.
NG >> Perform basic inspection. Refer to BRC-23, "
Basic Inspection" .
4. CHECK SELF-DIAGNOSTIC RESULTS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
NOTE:
When self-diagnostic results show items other than those above, perform repair or replacement for the item
indicated and repeat self-diagnosis.
Is the above displayed on self-diagnosis display?
YES >> Erase error memory.
NO >> Inspection End.ConditionData monitor display (Approx.)
PRESS SEN 2
When brake pedal is depressed Positive value
When brake pedal is released 0 bar
Self-diagnosis results
ST ANGL SEN SAFE

BRC-58
[VDC/TCS/ABS]
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
Unexpected Pedal ActionEFS0044U
1. CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to BRC-29, "
SELF-DIAGNOSIS" .
2. CHECK BRAKE PEDAL STROKE
Check brake pedal stroke.
Is pedal stroke excessive?
YES >> Perform Basic Inspection. Refer to BRC-23, "Basic
Inspection" .
NO >> GO TO 3.
3. CHECK CONNECTOR AND BRAKING PERFORMANCE
1. Disable ABS by disconnecting ABS actuator and electric unit (control unit) connector.
2. Drive vehicle and check brake operation.
NOTE:
Stopping distance may be longer than vehicles without ABS when road condition is slippery.
NOTE:
Driving the vehicle with the ABS actuator and electric unit (control unit) disconnected may induce DTCs in
electrical control units using CAN communication. After the inspection, clear all DTCs. Refer to BRC-10,
"CAN COMMUNICATION" .
OK or NG
OK >> GO TO 4.
NG >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .
4. CHECK WHEEL SENSORS
Check the following.

Wheel sensor mounting for looseness

Wheel sensors for physical damage

Wheel sensor connectors for terminal damage or loose connections
OK or NG
OK >> Check ABS actuator and electric unit (control unit) connector terminals for deformation, discon-
nection, looseness or damage. Reconnect ABS actuator and electric unit (control unit) harness
connector. Then retest.
NG >> Repair or replace as necessary.
SBR5 40 A

CO-12Revision: August 2007
RADIATOR
2004 QX56
10. Lift up and remove the radiator.
CAUTION:
Do not damage or scratch air conditioner condenser and
radiator core when removing.
INSTALLATION
Installation is in the reverse order of removal.
INSPECTION AFTER INSTALLATION

Check for leaks of engine coolant. Refer to CO-8, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually make sure that there are no leaks of the engine coolant.
Checking RadiatorEBS00NKC
Check radiator for mud or clogging. If necessary, clean radiator as follows.
CAUTION:

Be careful not to bend or damage the radiator fins.

When radiator is cleaned without removal, remove all surrounding parts such as cooling fan, radi-
ator shroud and horns. Then tape the harness and electrical connectors to prevent water from
entering.
1. Apply water by hose to the back side of the radiator core vertically downward.
2. Apply water again to all radiator core surfaces.
3. Stop washing when dirt and debris no longer flow out from the radiator.
4. Blow air into the back side of radiator core vertically downward.

Use compressed air lower than 490 kPa (5 kg/cm2 , 71 psi) and keep distance more than 30 cm (11.8
in).
5. Blow air again into all the radiator core surfaces until no water sprays out.
PBIC1536E

ENGINE COOLING FAN
CO-13
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Revision: August 20072004 QX56
ENGINE COOLING FANPFP:21140
Removal and Installation (Crankshaft Driven Type)EBS00I51
REMOVAL
1. Remove air duct. Refer to EM-14, "REMOVAL" .
2. Remove the engine front undercover using power tool.
3. Remove the lower radiator shroud. Refer to CO-10, "
RADIATOR" .
4. Remove cooling fan.
INSPECTION AFTER REMOVAL
Fan Coupling
Inspect fan coupling for oil leakage and bimetal conditions.
Fan Bracket

Visually check that there is no significant looseness in the fan
bracket shaft, and that it turns smoothly by hand.

If there are any unusual concerns, replace the cooling fan pulley.
INSTALLATION
Installation is in the reverse order of removal.

Install cooling fan with its front mark “F” facing front of engine. Refer to CO-13, "Removal and Installation
(Crankshaft Driven Type)" .
INSPECTION AFTER INSTALLATION

Check for leaks of the engine coolant. Refer to CO-8, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually make sure that there are no leaks of the engine coolant.
1. Cooling fan 2. Fan coupling 3. Fan bracket
4. Cooling fan pulley
WBIA0632E
SL C0 72
WBIA0418E

COMBINATION METERS
DI-23
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Revision: August 20072004 QX56
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.
WKIA2070E
Continuity should exist.
Continuity should not exist.
WKIA2071E

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.
WKIA1817E

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
WKIA1833E
Continuity should exist.
WKIA1837E
Voltage : Approx. 5V
WKIA1834E

WARNING CHIME
DI-49
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Revision: August 20072004 QX56
Terminals and Reference Value for Combination MeterEKS007EJ
How to Proceed With Trouble DiagnosisEKS007EK
1. Confirm the symptom or customer complaint.
2. Understand operation description and function description. Refer to DI-44, "
System Description" .
3. Perform the preliminary check. Refer to DI-49, "
Preliminary Check" .
4. Check symptom and repair or replace the cause of malfunction.
5. Does the warning chime operate properly? If so, go to 6. If not, go to 3.
6. Inspection End.
Preliminary CheckEKS007EL
INSPECTION FOR POWER SUPPLY AND GROUND CIRCUIT
1. CHECK FUSE AND FUSIBLE LINK
Check for blown BCM fuse or fusible link.
Refer to DI-46, "Wiring Diagram — CHIME —" .
OK or NG
OK >> GO TO 2.
NG >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse. Refer to PG-
4, "POWER SUPPLY ROUTING CIRCUIT" .
35 O/B Combination switch output 2
ON

Light switch and wiper switch
OFF

Wiper dial position 4 36 R/W Combination switch output 1
37 B/R Key switch signal OFFKey is removed 0
Key is inserted Battery voltage
38 W/L Ignition switch ON or START ON — Battery voltage
39 W CAN-H — — —
40 R CAN-L — — —
47 SB Front door switch LH signal OFFON (open) 0
OFF (closed) 5
67 B Ground OFF — 0
70 W/B Battery power supply OFF — Battery voltage Te r m i n a l
No.Wire
colorItem Condition
Reference value (V)
(Approx.) Ignition
switchMeasurement method
SKIA5292E
Te r m i n a l
No.Wire
colorItem Condition
Reference value (V)
(Approx.) Ignition
switchMeasurement method
11 W C A N - H — — —
12 R CAN-L — — —
27 O/B Seat belt buckle switch LH ONUnfastened (ON) 0
Fastened (OFF) Battery voltage
Unit Power source Fuse or fusible link No.
BCMBatteryf
Ignition switch ON or START 59

DI-64
REAR SONAR SYSTEM
Revision: August 20072004 QX56
Terminals And Reference Value For Sonar Control UnitEKS007EV
How to Proceed With Trouble DiagnosisEKS007EW
1. Confirm the symptom or customer complaint.
2. Understand operation description and function description. Refer to DI-60, "
System Description" .
3. Perform pre-diagnosis inspection. Refer to DI-65, "
Pre-diagnosis Inspection" .
4. Perform self-diagnosis. Refer to DI-65, "
Self-diagnosis Function" .
5. Perform the preliminary check. Refer to DI-67, "
Preliminary Check" .
6. Check symptom and repair or replace the cause of malfunction. Refer to DI-68, "
Symptom Chart" .
7. Does the rear sonar system operate properly? If so, go to 8. If not, go to 3.
8. Clear fault codes. Refer to DI-66, "
IDLING OR CLEARING FAULT CODES MODE" .
9. Inspection End.
TERMINAL
(COLOR)ITEMCONDITION
Reference value (V)
(Approx.) IGNITION
SWITCHOPERATION
3 (R) Sonar buzzer return ON — 0 - 12 (variable)
4 (BR/Y)Rear sonar system
OFF indicator outputONRear sonar system OFF
switch ON 0
OFF 12
5 (G/W) Reverse signal ONTransmission gear
selector leverR position 12
Transmission gear
selector leverNot R position 0
6 (B)Sonar control unit
ground —— 0
7 (L) Sonar buzzer drive
signalON — 12
8 (G/R)Sonar control unit
powerON — 12
9 (GR)Rear sonar sensor
signal - RH outerON

Rear sonar system OFF switch ON

Transmission gear selector lever in R
position

No obstacles12
10 (P)Rear sonar sensor
signal - LH outerON

Rear sonar system OFF switch ON

Transmission gear selector lever in R
position

No obstacles12
11 ( O )Rear sonar sensor
signal - LH innerON

Rear sonar system OFF switch ON

Transmission gear selector lever in R
position

Distance obstacles12
12 (LG)Rear sonar sensor
signal - RH innerON

Rear sonar system OFF switch ON

Transmission gear selector lever in R
position

Distance obstacles12
13 (LG)Rear sonar system
OFF switch signalONRear sonar system OFF
switchON 0
OFF 12
15 (Y)Rear sonar sensor
groundON — 0
16 (LG/B)Rear sonar sensor
powerON Ignition switch ON 12