2007 INFINITI QX56 fuel pressure

ACS-12
< SERVICE INFORMATION >[ICC]
LASER BEAM AIMING ADJUSTMENT
LASER BEAM AIMING ADJUSTMENT
Outline of Laser Beam Aiming Adjustment ProcedureINFOID:0000000003533782
CAUTION:
• The laser beam aiming adjustment cannot be performed without CONSULT-II.
• The laser beam aiming adjustment must be performed every time the ICC sensor is removed,
installed or has been moved as a result of a collision.
1. Prepare the vehicle and the work area.
2. Set up the ICC target board. For details, refer to Technical Service Bulletin.
3. Adjust the sensor following the procedure on CONSULT-II.
4. Check system operation after the adjustment.
PreparationINFOID:0000000003533783
• Place the vehicle on level ground. Shift the transmission into "P" position and release the parking brake.
• Adjust the tire pressure to the specified value.
• See that there is no load in the vehicle. Coolant, engine oil and fuel should be filled to correct level.
• Check that the vehicle suspension has been adjusted to the standard height by the load leveling rear air sus-
pension system. Refer to RSU-10, "
Basic Inspection" .
• Clean the sensor with a soft cloth.
Setting up the ICC Target BoardINFOID:0000000003533784
CAUTION:
Accuracy in setting up the ICC target board is essential for the laser beam aiming adjustment. For
details, refer to Technical Service Bulletin.
ADJUSTING HEIGHT OF THE TARGET
1. Attach a triangle scale as shown.Tool number : KV99110100 (J-45718)
LKIA0632E
WKIA1849E

A/T CONTROL SYSTEM
AT-37
< SERVICE INFORMATION >
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When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
• The current output from the TCM to the torque converter clutch solenoid is varied to gradually increase the
torque converter clutch solenoid pressure.
In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put into
half-clutched status, the torque converter clutch piston operating pressure is increased and the coupling is
completed smoothly.
Slip Lock-up Control
• In the slip region, the torque converter clutch solenoid current is controlled with the TCM to put it into the
half-clutched state. This absorbs the engine torque fluctuation and lock-up operates from low speed.
This raises the fuel efficiency for 4th and 5th gears at both low speed and when the accelerator has a low
degree of opening.
Engine Brake ControlINFOID:0000000003532236
• The forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse
drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.
• The operation of the low coast brake solenoid switches the low coast brake switching valve and controls the
coupling and releasing of the low coast brake.
The low coast brake reducing valve controls the low coast brake coupling force.
Control ValveINFOID:0000000003532237
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valveIn order to prevent the pressure supplied to the torque converter from being excessive,
the line pressure is adjusted to the optimum pressure (torque converter operating pres-
sure).
Pressure regulator valve
Pressure regulator plug
Pressure regulator sleeveAdjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valveWhen the front brake is coupled, adjusts the line pressure to the optimum pressure (front
brake pressure) and supplies it to the front brake. (In 1st, 2nd, 3rd, and 5th gears, adjusts
the clutch pressure.)
Accumulator control valveAdjusts the pressure (accumulator control pressure) acting on the accumulator piston
and low coast reducing valve to the pressure appropriate to the driving state.

BRC-8
< SERVICE INFORMATION >[VDC/TCS/ABS]
SYSTEM DESCRIPTION
ABS Function
INFOID:0000000003532769
• The Anti-Lock Brake System detects wheel revolution while braking and improves handling stability during
sudden braking by electrically preventing wheel lockup. Maneuverability is also improved for avoiding obsta-
cles.
• If the electrical system malfunctions, the Fail-Safe function is activated, the ABS becomes inoperative and
the ABS warning lamp turns on.
• The electrical system can be diagnosed using CONSULT-II.
• During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.
• Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.
• Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel, or
snow-covered (fresh, deep snow) roads.
EBD FunctionINFOID:0000000003532770
• Electronic Brake Distribution is a function that detects subtle slippages between the front and rear wheels
during braking, and it improves handling stability by electronically controlling the brake fluid pressure which
results in reduced rear wheel slippage.
• If the electrical system malfunctions, the Fail-Safe function is activated, the EBD and ABS become inopera-
tive, and the ABS warning lamp and BRAKE warning lamp are turned on.
• The electrical system can be diagnosed using CONSULT-II.
• During EBD operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.
• Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.
TCS FunctionINFOID:0000000003532771
• Spinning of the drive wheels is detected by the ABS actuator and electric unit (control unit) using inputs from
the wheel speed sensors. If wheel spin occurs, the drive wheel right and left brake fluid pressure control and
engine fuel cut are activated while the throttle value is restricted to reduce the engine torque and decrease
the amount of wheel spin. In addition, the throttle opening is controlled to achieve the optimum engine
torque.
• Depending on road condition, the vehicle may have a sluggish feel. This is normal, because optimum trac-
tion has the highest priority during TCS operation.
• TCS may be activated during sudden vehicle acceleration, wide open throttle acceleration, sudden transmis-
sion shifts or when the vehicle is driven on a road with a varying surface friction coefficient.
• The SLIP indicator lamp flashes to inform the driver of TCS operation.
VDC FunctionINFOID:0000000003532772
• In addition to the ABS/TCS function, the driver steering amount and brake operation amount are detected
from the steering angle sensor and front and rear pressure sensors, and the vehicle's driving status (amount
of under steering/over steering) is determined using inputs from the yaw rate sensor/side G sensor, wheel
speed sensors, etc. and this information is used to improve vehicle stability by controlling the braking and
engine torque application to the wheels.
• The SLIP indicator lamp flashes to inform the driver of VDC operation.
• During VDC operation, the vehicle body and brake pedal may vibrate lightly and a mechanical noise may be
heard. This is normal.
• The ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp may turn on when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the
engine is running or on a steep slope. In this case, restart the engine on a normal road and if the ABS warn-
ing lamp, VDC OFF indicator lamp and SLIP indicator lamp turn off, there is no problem.
Fail-Safe FunctionINFOID:0000000003532773
CAUTION:
If the Fail-Safe function is activated, perform the Self Diagnosis for ABS/TCS/VDC system.
ABS/EBD SYSTEM

TROUBLE DIAGNOSIS
BRC-29
< SERVICE INFORMATION >[VDC/TCS/ABS]
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Note 1: If wheel sensor 2 for each wheel is indicated, check ABS actuator and electric unit (control unit) power supply voltage in addition
to wheel sensor circuit check.
Note 2: If multiple malfunctions are detected including CAN communication line [U1000], perform diagnosis for CAN communication line
first.
DATA MONITOR
Display Item List
CONTROLLER FAILURE
[ C 111 0 ]Internal malfunction of ABS actuator and electric unit (control
unit).BRC-35, "ABS/TCS/VDC
Control Unit Inspection"
CAN COMM CIRCUIT
[U1000]• CAN communication line is open or shorted.
• ABS actuator and electric unit (control unit) internal malfunction
• Battery voltage for ECM is suddenly interrupted for approxi-
mately 0.5 second or more.LAN-7 (Note 2)
SIDE G-SEN CIRCUIT
[C1146]Lateral G-sensor is malfunctioning, or signal line of lateral G-sen-
sor is open or shorted.BRC-37, "
Yaw Rate/
Side/Decel G Sensor
System Inspection"
BR FLUID LEVEL LOW
[C1155]Brake fluid level drops or circuit between ABS actuator and elec-
tric unit (control unit) and brake fluid level switch is open or
shorted.BRC-42, "Brake Fluid
Level Switch System In-
spection"
ENGINE SIGNAL 1
[C1130]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
BRC-35, "
Engine System
Inspection"
ENGINE SIGNAL 2
[C1131]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ENGINE SIGNAL 3
[C1132]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ENGINE SIGNAL 4
[C1133]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ENGINE SIGNAL 6
[C1136]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ACTUATOR RLY
[C1140]ABS actuator relay or circuit malfunction.BRC-39, "
Actuator Mo-
tor, Motor Relay, and Cir-
cuit Inspection"
PRESS SEN CIRCUIT
[C1142]ABS pressure sensor circuit malfunction.BRC-45, "Pressure Sen-
sor System Inspection"
VARIANT CODING
[C1170]V coding is not malfunctioning.BRC-35, "ABS/TCS/VDC
Control Unit Inspection"
ABS ACTIVE BOOSTER SV NG
[C1178]Active booster solenoid is malfunctioning, or signal line of active
booster servo is open or shorted.BRC-43, "Active Booster
System Inspection"
ABS DELTA S SEN NG
[C1179]Delta stroke sensor malfunctioning, or signal line of delta stroke
sensor is open or shorted.BRC-44, "Delta Stroke
Sensor System Inspec-
tion"
ABS ACTIVE BOOSTER RE-
SPONSE NG
[C1181]Active booster response is malfunctioning, or signal line of active
booster response is open or shorted.BRC-43, "Active Booster
System Inspection"
ABS BRAKE RELEASE SW NG
[C1184]Brake release switch is malfunctioning, or signal line of brake re-
lease switch is open or shorted.BRC-43, "Active Booster
System Inspection"
ABS ACC CU INTERNAL NG
[C1185]ICC control unit internal malfunction.BRC-48, "ICC System In-
spection"
ABS BRAKE BOOSTER DEFECT
[C1189]Brake booster is defective or malfunctioning.BRC-43, "Active Booster
System Inspection"
Self-diagnostic item Malfunction detecting condition Check system

DI-1
ELECTRICAL
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CONTENTS
DRIVER INFORMATION SYSTEM
SERVICE INFORMATION .. ..........................3
PRECAUTION ................................................ .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
PREPARATION ...................................................4
Commercial Service Tool .................................... ......4
COMBINATION METERS ...................................5
Component Parts and Harness Connector Loca-
tion ...................................................................... ......
5
System Description ...................................................5
Arrangement of Combination Meter ..........................7
Internal Circuit ...........................................................8
Wiring Diagram - METER - .......................................9
Combination Meter Harness Connector Terminal
Layout .....................................................................
11
Terminal and Reference Value for Combination
Meter .......................................................................
11
Self-Diagnosis Mode of Combination Meter ........ ....12
How to Proceed with Trouble Diagnosis ............. ....15
Preliminary Check ...................................................15
Symptom Chart .......................................................16
Power Supply and Ground Circuit Inspection .........16
Vehicle Speed Signal Inspection .............................17
Engine Oil Pressure Signal Inspection ....................17
Water Temperature Signal Inspection .....................18
Engine Speed Signal Inspection ......................... ....18
Fuel Level Sensor Unit Inspection ...................... ....18
Fuel Gauge Fluctuates, Indicates Wrong Value, or
Varies .................................................................. ....
20
Fuel Gauge Does Not Move to Full-position ...........20
Electrical Component Inspection ......................... ....21
Removal and Installation of Combination Meter .....21
COMPASS AND THERMOMETER ................ ....22
System Description ............................................. ....22
Wiring Diagram - COMPAS - ..................................23
Trouble Diagnosis ............................................... ....23
Calibration Procedure for Compass .................... ....24
WARNING LAMPS ............................................26
Schematic ............................................................ ....26
Wiring Diagram - WARN - .......................................27
Oil Pressure Warning Lamp Stays Off (Ignition
Switch ON) .......................................................... ....
32
Oil Pressure Warning Lamp Does Not Turn Off
(Oil Pressure Is Normal) ...................................... ....
33
A/T INDICATOR ................................................34
Wiring Diagram - AT/IND - .......................................34
A/T Indicator Does Not Illuminate ............................34
WARNING CHIME .............................................36
Component Parts and Harness Connector Loca-
tion ....................................................................... ....
36
System Description ..................................................36
CAN Communication System Description ...............37
Wiring Diagram - CHIME - .......................................38
Terminal and Reference Value for BCM ..................39
Terminal and Reference Value for Combination
Meter ................................................................... ....
39
How to Proceed with Trouble Diagnosis ..................40
Preliminary Check ............................................... ....40
CONSULT-II Function (BCM) ..................................40
All Warning Chimes Do Not Operate .......................41
Key Warning Chime and Light Warning Chime Do
Not Operate (Seat Belt Warning Chime Does Op-
erate) .......................................................................
41
Key Warning Chime Does Not Operate ...................42
Light Warning Chime Does Not Operate .................44
Seat Belt Warning Chime Does Not Operate ..........44
REAR SONAR SYSTEM ...................................46
Component Parts and Harness Connector Loca-
tion ....................................................................... ....
46
System Description ..................................................46
Wiring Diagram - SONAR - ......................................48
Sonar Control Unit Harness Connector Terminal
Layout ......................................................................
50

COMBINATION METERSDI-5
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COMBINATION METERS
Component Parts and Har ness Connector LocationINFOID:0000000003533479
System DescriptionINFOID:0000000003533480
UNIFIED METER CONTROL UNIT
• Speedometer, odometer, tachometer, fuel gauge, oil pressure gauge, voltage gauge, A/T oil temperature
gauge, and water temperature gauge are controlled by the unified meter control unit, which is built into the
combination meter.
• Warning indicators are controlled by signals drawn fr om the CAN communication system, BCM (body control
module), and components connected directly to the combination meter.
• Digital meter is adopted for odometer/trip meters*, as well as the A/T position indicator display. *The record of the odometer is kept ev en if the battery cable is disconnected.
• Odometer/trip meters and A/T indicator segments can be checked in diagnosis mode.
• Meters/gauges can be checked in diagnosis mode.
Illumination control
The unified meter control unit outputs the speedometer, odometer/trip meters, tachometer, oil pressure gauge,
voltage meter, A/T indicator, A/T temperature gauge, fuel and temperature gauge lighting when the ignition
switch is turned on. When the lighting switch is turned on, the illumination control switch can be used to adjust
the brightness of the combination meter illuminati on and the odometer/trip meters and meter illumination.
When the ignition switch is turned from the OFF to the ON position, the combination meter dial lighting will
remain off for 0.7 seconds. For additional combination meter illumination control information, refer to LT-120,
"System Description".
1. IPDM E/R E122 2. Combination meter M24 3. Fuel level sensor unit and fuel pump
C5 (view with inspection hole cover
removed)
4. ECM E16 (view with battery re- moved) 5. ABS actuator and electric unit (con-
trol unit) E125 6. Oil pressure switch F4
A. Oil pan (upper)
7. A/T assembly F9
WKIA5718E

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.

COMBINATION METERSDI-11
< SERVICE INFORMATION >
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Combination Meter Harness Connector Terminal LayoutINFOID:0000000003533484
Terminal and Reference Va lue for Combination MeterINFOID:0000000003533485
LKIA0698E
Te r m i n a l
No. Wire
color Item Condition
Reference value (V)
(Approx.)
Ignition
switch Operation or condition
1 O Ignition switch ACC or ON ON — Battery voltage
8 Y/R Battery power supply OFF — Battery voltage
9 R/G Stop lamp switch ON Brake pedal depressed Battery voltage
Brake pedal released 0
10 P/B Brake fluid level switch ON Brake fluid level low 0
Brake fluid level normal Battery voltage
11 L C A N - H — — —
12 P CAN-L — — —
14 P/L Seat belt buckle switch
RH ONUnfastened (ON) 0
Fastened (OFF) Battery voltage
15 Y/L Fuel level sensor signal — — Refer to
DI-18, "
Fuel Level Sensor
Unit Inspection".
16 B/P Fuel level sensor and oil
pressure sensor ground ON — 0V
17 B Ground — — 0V
18 BR Illumination control switch — Lighting switch ON Refer to
LT- 1 2 0 , "
System Descrip-
tion".
23 G Parking Brake switch ON Parking brake applied 0
Parking brake released Battery voltage
24 O/L Ignition switch ON or
START ON — Battery voltage
27 O/B Seat belt buckle pre-ten-
sioner assembly LH (seat
belt buckle switch) ON
Unfastened (ON) 0
Fastened (OFF) Battery voltage
28 G/O Security indicator input OFF Security indicator ON 0
Security indicator
OFF Battery voltage
29 W/R Vehicle speed signal
(8-pulse) ONSpeedometer operated
[When vehicle speed is ap-
prox. 40 km/h (25 MPH)]
PKIA1935E