2007 INFINITI QX56 change time

BL-8
< SERVICE INFORMATION >
SQUEAK AND RATTLE TROUBLE DIAGNOSIS
Most of these incidents can be repaired by adjusting, securing or insulating the item(s) or component(s) caus-
ing the noise.
SUNROOF/HEADLINING
Noises in the sunroof/headlining area can often be traced to one of the following:
1. Sunroof lid, rail, linkage or seals making a rattle or light knocking noise
2. Sun visor shaft shaking in the holder
3. Front or rear windshield touching headliner and squeaking
Again, pressing on the components to stop the noise while duplicating the conditions can isolate most of these
incidents. Repairs usually consist of insulating with felt cloth tape.
OVERHEAD CONSOLE (FRONT AND REAR)
Overhead console noises are often caused by the console panel clips not being engaged correctly. Most of
these incidents are repaired by pushing up on the console at the clip locations until the clips engage.
In addition look for:
1. Loose harness or harness connectors.
2. Front console map/reading lamp lense loose.
3. Loose screws at console attachment points.
SEATS
When isolating seat noise it's important to note the position the seat is in and the load placed on the seat when
the noise is present. These conditions should be duplicated when verifying and isolating the cause of the
noise.
Cause of seat noise include:
1. Headrest rods and holder
2. A squeak between the seat pad cushion and frame
3. The rear seatback lock and bracket
These noises can be isolated by moving or pressing on the suspected components while duplicating the con-
ditions under which the noise occurs. Most of these incidents can be repaired by repositioning the component
or applying urethane tape to the contact area.
UNDERHOOD
Some interior noise may be caused by components under the hood or on the engine wall. The noise is then
transmitted into the passenger compartment.
Causes of transmitted underhood noise include:
1. Any component mounted to the engine wall
2. Components that pass through the engine wall
3. Engine wall mounts and connectors
4. Loose radiator mounting pins
5. Hood bumpers out of adjustment
6. Hood striker out of adjustment
These noises can be difficult to isolate since they cannot be reached from the interior of the vehicle. The best
method is to secure, move or insulate one component at a time and test drive the vehicle. Also, engine RPM
or load can be changed to isolate the noise. Repairs can usually be made by moving, adjusting, securing, or
insulating the component causing the noise.

BL-84
< SERVICE INFORMATION >
AUTOMATIC BACK DOOR SYSTEM
Warning Chime Active Conditions
The warning chime uses two types of audio warnings, a friendly chime and a warning chime. The friendly
chime consists of dings lasting 0.66 seconds each immediately followed by the next ding. The warning chime
consists of beeps lasting 0.33 seconds with a pause of 0.33 seconds between each beep.
Reverse Conditions
Description Operation Control
Back door close switch turned to CANCELWarning chime active
→ Shift to manual mode after full open or
close operation is complete
(Recovery to power mode when main
switch turned OFF or door fully closed)→ Shift to manual mode
A/T selector lever P or N position with igni-
tion switch ONWarning chime active and one-way opera-
tion continuous
(Warning chime inactive and door fully open
or fully closed or operating conditions re-
covered)Full open: power close operation allowed
Full close: operating conditions not met →
no power open function.
Voltage drop 11 - 9VOne-way operation continued (equivalent
to the case of starting voltage ← 11V for
handle operation with warning chime ac-
tive)Not allowed
Voltage drop less than 9V
(Microcomputer reset voltage - clutch hold
voltage)• Motor stopped
• Clutch may slip
• Control not possible because microcom-
puter being resetControl not possible because microcomput-
er being reset
Operation status Operation or conditions Warning chime pattern
When auto operation startsPower liftgate switch operation
Friendly chime
2 seconds, 3 dings Remote keyless entry operation
Back door handle switch operation
Back door close switch operation
When reverse operation startsWhen reverse request is detected from
power liftgate switch, remote keyless
entry or back door close switchFriendly chime
1.3 seconds, 2 dings
When obstacle is detectedWarning chime
2 seconds, 3 beeps
Operating at low voltage While opening or closing Warning chime
2 seconds, 3 beeps
A/T selector lever not in P positionBack door close operationFriendly chime
Continuously dings
Back door open operationWarning chime
Continuously beeps
(until close operation is started)
Type Overload reverse
Operation covered Both directions
Detection methodOperation speed and motor current change direction
Pinch strips during back door close operation
Non-reversed area• For about 0.5 seconds immediately after drive motor operation
starts
• Between full open and approx. 7° from full open
• Closure operation area (half switch - close switch)
Number of times reverse allowedOne reversal is allowed (if a second obstacle is detected during a
power open or close operation, the door reverts to manual mode).

BRAKE BOOSTER
BR-15
< SERVICE INFORMATION >
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BRAKE BOOSTER
On-Vehicle ServiceINFOID:0000000003532734
OPERATING CHECK
With engine stopped, change the vacuum to the atmospheric pres-
sure by depressing brake pedal several times. Then with brake
pedal fully depressed, start engine and when the vacuum pressure
reaches the standard, make sure the clearance between brake pedal
and floor panel decreases.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
AIRTIGHT CHECK
• Run engine at idle for approximately 1 minute, and stop it after
applying vacuum to booster. Depress brake pedal normally to
change the vacuum to the atmospheric pressure. Make sure dis-
tance between brake pedal and floor panel gradually increases.
• Depress brake pedal while engine is running and stop engine with
pedal depressed. The pedal stroke should not change after holding
pedal down for 30 seconds.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
Removal and InstallationINFOID:0000000003532735
REMOVAL
CAUTION:
• Be careful not to deform or bend brake piping while removing and installing brake booster.
• Replace clevis pin if it is damaged.
BRA0037D
SBR365AA
1. Reservoir tank 2. Brake master cylinder 3. Gasket
4. Brake pedal 5. Lock nut 6. Spacer block
7. Brake booster 8. Active booster 9. Delta stroke sensor
WFIA0381E

DI-6
< SERVICE INFORMATION >
COMBINATION METERS
POWER SUPPLY AND GROUND CIRCUIT
Power is supplied at all times
• through 10A fuse [No.19, located in the fuse block (J/B)]
• to combination meter terminal 8.
With the ignition switch in the ON or START position, power is supplied
• through 10A fuse [No.14, located in the fuse block (J/B)]
• to combination meter terminal 24.
Ground is supplied
• to combination meter terminal 17
• through body grounds M57, M61 and M79.
WATER TEMPERATURE GAUGE
The water temperature gauge indicates the engine coolant temperature.
ECM provides an engine coolant temperature signal to combination meter via CAN communication lines.
ENGINE OIL PRESSURE GAUGE
The engine oil pressure gauge indicates whether the engine oil pressure is low or normal.
The oil pressure gauge is controlled by the IPDM E/R (intelligent power distribution module engine room). Low
oil pressure causes oil pressure switch terminal 1 to provide ground to IPDM E/R terminal 42. The IPDM E/R
then signals the combination meter (unified meter control unit) via CAN communication lines and a low oil
pressure indication is displayed by the oil pressure gauge.
A/T OIL TEMPERATURE GAUGE
The A/T oil temperature gauge indicates the A/T fluid temperature.
TCM (transmission control module) provides an A/T flui d temperature signal to combination meter via CAN
communication lines.
VOLTAGE GAUGE
The voltage gauge indicates the battery/charging system voltage.
The voltage gauge is regulated by the unified meter control unit.
TA C H O M E T E R
The tachometer indicates engine speed in revolutions per minute (rpm).
ECM provides an engine speed signal to combination meter via CAN communication lines.
FUEL GAUGE
The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by the unified meter control unit and a variable resistor signal supplied
• to combination meter terminal 15.
• through fuel level sensor unit and fuel pump terminal 2
• through fuel level sensor unit and fuel pump terminal 5
• from combination meter terminal 16
SPEEDOMETER
ABS actuator and electric unit (contro l unit) provides a vehicle speed signal to the combination meter via CAN
communication lines.
ODO/TRIP METER
The vehicle speed signal and the memory signals from the meter memory circuit are processed by the combi-
nation meter and the mileage is displayed.
How to Change the Display
Refer to Owner's Manual for odo/tr ip meter operating instructions.
CAN COMMUNICATION SYSTEM DESCRIPTION
Refer to LAN-4.

DI-20
< SERVICE INFORMATION >
COMBINATION METERS
1. Check continuity between combination meter harness connectorM24 (B) terminal 16 and fuel level sensor unit and fuel pump
harness connector C5 (A) terminal 5.
2. Check continuity between fuel level sensor unit and fuel pump harness connector C5 (A) terminal 5 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-21, "
Electrical Component Inspection".
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 whet her 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-10, "Removal and Installation".
NG >> Install the fuel level sensor unit properly.
Fuel Gauge Fluctuat es, Indicates Wrong Value, or VariesINFOID:0000000003533496
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 leve l change in the fuel tank. Condition is normal.
NO >> Ask the customer about the situation when the symptom occurs in detail, Refer to DI-18, "
Fuel
Level Sensor Unit Inspection".
Fuel Gauge Does Not Move to Full-positionINFOID:0000000003533497
1.CHECK POINTER MOVEME NT 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 s witch 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. Continuity should exist.
Continuity should not exist.
WKIA4618E

DI-24
< SERVICE INFORMATION >
COMPASS AND THERMOMETER
1. Turn the ignition switch to the ON position.
2. Cool down ambient sensor 2 with water or ice.
Does the indicated temperature drop?
YES >> GO TO 2.
NO >> The system is malfunctioning. Check the system following “INSPECTION/COMPASS AND THER-
MOMETER”. Refer to "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 ambient sensor 2 connector.
Does the indicated temperature rise?
YES >> The system is OK.
NO >> The system is malfunctioning. Check the system following “INSPECTION/COMPASS AND THER-
MOMETER”. Refer to "INSPECTION/COMPASS AND THERMOMETER".
INSPECTION/COMPASS AND THERMOMETER
Calibration Procedure for CompassINFOID:0000000003533503
The difference between magnetic North and geographical North can sometimes be great enough to cause
false compass readings. In order for the compass to operate accurately in a particular zone, it must be cali-
brated using the following procedure.
Symptom Possible causes Repair order
No display at all 1. 10A fuse.
2. Ground circuit.
3. auto anti-dazzling inside mirror.1. Check 10A fuse [No. 12, located in fuse block (J/B)].
Turn the ignition switch ON and verify that battery positive
voltage is at terminal 6 of auto anti-dazzling inside mirror.
2. Check ground circuit for auto anti-dazzling inside mirror.
3. Replace auto anti-dazzling inside mirror.
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.
Displays wrong temper-
ature when ambient
temperature is between
−40°C (−40°F) and
55°C (130°F)1. Check operation.
2. Ambient sensor 2 circuit.
3. Ambient sensor 2.
4. Auto anti-dazzling inside mirror.1. Perform preliminary check shown above.
2. Check harness for open or short between ambient sensor 2
and auto anti-dazzling inside mirror.
3. Replace ambient sensor 2.
4. Replace auto anti-dazzling inside mirror.
Displays SC or OC 1. Ambient sensor 2 circuit.
2. Ambient sensor 2.
3. Auto anti-dazzling inside mirror.1. Check harness for open or short between ambient sensor 2
and auto anti-dazzling inside mirror.
2. Replace ambient sensor 2.
3. Replace auto anti-dazzling inside mirror.

ENGINE CONTROL SYSTEM
EC-25
< SERVICE INFORMATION >
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*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.
• During warm-up
• When starting the engine
• During acceleration
• Hot-engine operation
• When selector lever is changed from N to D
• High-load, high-speed operation

• During deceleration
• During high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)
VDC/TCS operation command*
2
Air conditioner switch
Air conditioner operation*2
Wheel sensor
Vehicle speed*2
PBIB3020E

EC-26
< SERVICE INFORMATION >
ENGINE CONTROL SYSTEM
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses air
fuel ratio (A/F) sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about air
fuel ratio (A/F) sensor 1, refer to EC-225
. This maintains the mixture ratio within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of air fuel ratio (A/F) sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
• Deceleration and acceleration
• High-load, high-speed operation
• Malfunction of A/F sensor 1 or its circuit
• Insufficient activation of A/F sensor 1 at low engine coolant temperature
• High engine coolant temperature
• During warm-up
• After shifting from N to D
• When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in
fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all eight cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The eight fuel injectors will then receive the signals two times for each engine cycle.
PBIB0122E