2008 INFINITI QX56 brake fluid

PRECAUTIONSBRC-111
< PRECAUTION > [VDC/TCS/ABS]
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5. When the repair work is completed, return the ignition switch to the ″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
Precaution for Brake SystemINFOID:0000000001604543
CAUTION:
• Always use recommended brake fluid. Refer to MA-12, "
Fluids and Lubricants".
• Never reuse drained brake fluid.
• Be careful not to splash brake fluid on painted areas; it may cause paint damage. If brake fluid is
splashed on painted areas, wash it away with water immediately.
• To clean or wash all parts of master cylin der and disc brake caliper, use clean brake fluid.
• Never use mineral oils such as gasoline or kerosen e. They will ruin rubber parts of the hydraulic sys-
tem.
• Use flare nut wrench when removing and installing brake
tube.
• If a brake fluid leak is found, the part must be disassembled
without fail. Then it has to be replaced with a new one if a
defect exists.
• Turn the ignition switch OFF and remove the connector of the ABS actuator and electric unit (con trol unit) or the battery ter-
minal before performing the work.
• Always torque brake lines when installing.
• Burnish the brake contact surf aces after refinishing or replac-
ing rotors, after replacing pads, or if a soft pedal occurs at
very low mileage.
Refer to BR-30, "
Brake Burnishing Procedure" (front disc brake) or BR-35, "Brake Burnishing Proce-
dure" (rear disc brake).
WARNING:
• Clean brake pads and shoes with a waste cl oth, then wipe with a dust collector.
Precaution for Brake ControlINFOID:0000000001604544
• During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.
• Just after starting 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.
• When an error is indicated by ABS or another warning lamp, collect all necessary information from customer (what symptoms are present under what conditions) and check for simple causes before starting diagnosis.
Besides electrical system inspection, check boos ter operation, brake fluid level, and fluid leaks.
• If incorrect tire sizes or types are installed on the vehicle or brake pads are not Genuine NISSAN parts, stop-
ping distance or steering stability may deteriorate.
• If there is a radio, antenna or related wiring near control module, ABS function may have a malfunction or
error.
• If aftermarket parts (car stereo, CD player, etc.) have been installed, check for incidents such as harness pinches, open circuits or improper wiring.
• If the following components are replaced with non-genuine components or modified, the VDC OFF indicator lamp and SLIP indicator lamp may turn on or the VDC system may not operate properly. Components
related to suspension (shock absorbers, struts, springs , bushings, etc.), tires, wheels (exclude specified
size), components related to brake system (pads, roto rs, calipers, etc.), components related to engine (muf-
fler, ECM, etc.), components related to body reinforcement (roll bar, tower bar, etc.).
• Driving with broken or excessively worn suspensi on components, tires or brake system components may
cause the VDC OFF indicator lamp and the SLIP indicator lamp to turn on, and the VDC system may not
operate properly.
• When the TCS or VDC is activated by sudden acceleration or sudden turn, some noise may occur. The noise is a result of the normal operation of the TCS and VDC.
• When driving on roads which have extreme slopes (such as mountainous roads) or high banks (such as sharp curves on a freeway), the VDC may not operate no rmally, or the VDC warning lamp and the SLIP indi-
cator lamp may turn on. This is not a problem if normal operation can be resumed after restarting the engine.
SBR686C
Revision: March 2010 2008 QX56

BRC-114
< REMOVAL AND INSTALLATION >[VDC/TCS/ABS]
WHEEL SENSORS
REMOVAL AND INSTALLATION
WHEEL SENSORS
Removal and InstallationINFOID:0000000001604548
REMOVAL
1. Remove wheel sensor bolt.
• When removing the front wheel sensor, first remove t he disc rotor to gain access to the front wheel sen-
sor bolt. Refer to BR-31, "
Removal and Installation of Brake Caliper and Rotor" .
• When removing the rear wheel sensor, first remove the rear hub and bearing assembly to gain access to
the rear wheel sensor bolt. Refer to RAX-8, "
Removal and Installation".
2. Pull out the sensor, being careful to turn it as little as possible. CAUTION:
• Do not pull on the sensor harness.
3. Disconnect wheel sensor harness electrical connec tor, then remove harness from attaching points.
INSTALLATION
Installation is in the reverse order of removal. Tighten wheel sensor bolt to specification.
CAUTION:
• Inspect wheel sensor O-ring, replace sensor assembly if damaged.
• Before installing wheel sensor, make sure no foreign materials (such as iron fragments) are adhered
to the pick-up part of the sensor, to the inside of the sensor hole or on the rotor mating surface.
• Apply a coat of suitable grease to the wheel sensor O-ring and hole. Refer to MA-12, "
Fluids and
Lubricants" .
WFIA0376E
Revision: March 2010 2008 QX56

BRC-116
< REMOVAL AND INSTALLATION >[VDC/TCS/ABS]
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
Removal and InstallationINFOID:0000000001604550
REMOVAL
1. Disconnect the negative battery terminal.
2. Remove the air duct and resonator assembly and air cleaner case. Refer to
EM-25, "
Removal and Instal-
lation".
3. Drain the brake fluid. Refer to BR-17, "
Drain and Refill" .
4. Disconnect the actuator harness from the ABS actuator and electric unit (control unit).
5. Disconnect the brake tubes. CAUTION:
• To remove the brake tubes, use a flare nut wrench to prevent the flare nuts and brake tubes from
being damaged.
• Be careful not to splash brake fluid on painted areas.
6. Remove the three bolts and remove the ABS actuator and electric unit (control unit).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
To install, use a flare nut wr ench (commercial service tool).
1. To rear left caliper
13 N·m (1.3 kg-m, 10 ft-lb) 2. To rear right caliper
13 N·m (1.3 kg-m, 10 ft-lb) 3. To front left caliper
13 N·m (1.3 kg-m, 10 ft-lb)
4. To front right caliper 13 N·m (1.3 kg-m, 10 ft-lb) 5. From the master cylinder secondary side
18.2 N·m (1.9 kg-m, 13 ft-lb) 6. From the master cylinder primary side
18.2 N·m (1.9 kg-m, 13 ft-lb)
7. ABS actuator and electric unit (control unit) 8. Actuator harness connector
WFIA0375E
Revision: March 2010
2008 QX56

ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)BRC-117
< REMOVAL AND INSTALLATION > [VDC/TCS/ABS]
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• Always tighten brake tubes to specifi cation when installing. Refer to BR-21, "Hydraulic Circuit" .
• Never reuse drained brake fluid.
• After installation of the ABS actuator and elect ric unit (control unit), perform the following.
- Refill brake system with new br ake fluid. Then bleed the air from the system. Refer to BR-17, "
Bleed-
ing Brake System" .
- Adjust the steering angle sensor. Refer to BRC-8, "
ADJUSTMENT OF STEERING ANGLE SENSOR
NEUTRAL POSITION : Speci al Repair Requirement" .
- Calibrate the decel G sensor. Refer to BRC-9, "
CALIBRATION OF DECEL G SENSOR : Special Repair
Requirement" .
Revision: March 2010 2008 QX56

CCS-16
< FUNCTION DIAGNOSIS >
INTELLIGENT CRUISE CONTROL SYSTEM
Component Description
INFOID:0000000001731812
× : Applicable
4. ICC brake hold relay E134 5. ICC sensor E426. ICC brake switch E37
7. Stop lamp switch E38 8. ICC unit B13, B17
(view with luggage side finisher low-
er LH removed)
Component Veh ic le-t o-
vehicle
distance
control mode Conventional
(Fixed speed)
cruise
control mode Brake assist
(With preview function) Description
ICC unit ××× Controls vehicle speed through ECM via CAN commu-
nication.
ICC sensor ××× Measures distance to objects in front of the vehicle and
transmits that information to the ICC unit.
ECM ××× Refer to EC-21, "
System Diagram".
ABS actuator and electric
unit (control unit) ×××
Refer to BRC-18, "
System Description".
Brake pressure sensor ×× Detects brake fluid pressure.
Brake booster ×× Adjusts brake fluid pressure based on command from
ABS actuator and electric unit (control unit).
BCM × Transmits front wiper request signal to ICC sensor inte-
grated unit through CAN communication.
TCM ×× Refer to TM-20, "
TCM Function".
Revision: March 2010 2008 QX56

DLN-80
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
ECU DIAGNOSIS
TRANSFER CONTROL UNIT
Reference ValueINFOID:0000000001737179
VALUE ON THE DIAGNOSIS TOOL
CONSULT-III data monitor item
Monitored item [Unit]
Content ConditionDisplay value
VHCL/S SEN·FR [km/h]
or [mph] Wheel speed (Front
wheel) Vehicle stopped
0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition. Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
VHCL/S SEN·RR [km/h]
or [mph] Wheel speed (Rear
wheel) Vehicle stopped
0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition. Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
ENGINE SPEED [rpm] Engine speed Engine stopped
(Engine speed: Less than 400 rpm)
0 rpm
Engine running
(Engine speed: 400 rpm or more) Approximately
equal to the indica-
tion on tachometer
THRTL POS SEN [V] Accelerator
pedal posi-
tion (APP) sensor signal
voltage Accelerator pedal: Released
Approx. 0.5V
Accelerator pedal: Fully depressed Approx. 4.0V
FLUID TEMP SE [V] Transfer fluid tempera-
ture signal voltage Transfer fluid temperature approx. 20 - 80
°C (68 - 176 °F) Approx. 1.1 - 0.3V
BATTERY VOLT [V] Power supply voltage for
transfer control unit Ignition switch: ON
Battery voltage
2WD SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 2WD
ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: AUTO
ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: 4H
ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 4LO
ON
4WD shift switch: 2WD, AUTO or 4H OFF
N POSI SW TF [ON/
OFF] Condition of neutral-4LO
switch • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.) OFF
→ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→OFF
4WD shift switch: 4LO ON
Revision: March 2010 2008 QX56

DLN-86
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
25 V Neutral-4LO switch• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)
Battery voltage
→
0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
27 W/L Actuator position switch 2
(High) • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed 4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO
Battery voltage
28 B/G Sensor ground Always0V
29 L/W Ignition switch monitor Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relay Ignition switch: ON
0V
Ignition switch: OFF Battery voltage
31 G Transfer fluid temperature
sensor
Ignition switch: ONTransfer fluid temperature approx. 20
°C
(68 °F) 1.1V
Transfer fluid temperature approx. 80 °C
(176 °F) 0.3V
33 R/L Transfer shift high relay
monitor • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
34 BR Clutch pressure switch • Vehicle stopped
• Engine running
• A/T selector lever
“D” position 4WD shift switch: AUTO or 4H (“Wait” func-
tion is not operating.)
0V
• Vehicle stopped
• Engine running 4WD shift switch: 2WD (“Wait” function is
not operating.)
Battery voltage
35 BR/
W Line pressure switch • Ignition switch: ON
• A/T selector lever “D” position
• 4WD shift switch: AUTO
0V
• After the vehicle has been left at
room temperature
for 5 minutes and
more with ignition
switch in “OFF” po-
sition. • Ignition switch: ON
• A/T selector lever: “P” or "N" position
• 4WD shift switch: other than AUTO
Battery voltage
40 L ATP switch • Vehicle stopped
• Engine running
• A/T selector lever
“N”
• Brak e

pedal de-
pressed 4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
0V
Except the above Battery voltage
Te r m i n a l
Wire
color Item
ConditionData (Approx.)
Revision: March 2010 2008 QX56

DLN-240
< SYMPTOM DIAGNOSIS >[REAR FINAL DRIVE: R230]
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING
SYMPTOM DIAGNOSIS
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting ChartINFOID:0000000001604455
Use the chart below to help you find the cause of the sy mptom. If necessary, repair or replace these parts.
×: ApplicableReference page
DLN-251, "
Disassembly and Assembly
"
DLN-251, "
Disassembly and Assembly
"
DLN-251, "
Disassembly and Assembly
"
DLN-268, "
Inspection and Adjustment
"
DLN-268, "
Inspection and Adjustment
"
MA-12, "
Fluids and Lubricants
"
DLN-192, "
NVH Troubleshooting Chart
"
DLN-240, "
NVH Troubleshooting Chart
"
RSU-5, "
NVH Troubleshooting Chart
"
WT-41, "
NVH Troubleshooting Chart
"
WT-41, "
NVH Troubleshooting Chart
"
RAX-5, "
NVH Troubleshooting Chart
"
BR-6, "
NVH Troubleshooting Chart
"
ST-12, "
NVH Troubleshooting Chart
"
Possible cause and SUSPECTED PARTS
Gear tooth rough
Gear contact improper
Tooth surfaces worn
Backlash incorrect
Companion flange excessive runout
Gear oil improper
PROPELLER SHAFT
REAR AXLE
REAR SUSPENSION
TIRES
ROAD WHEEL
DRIVE SHAFT
BRAKES
STEERING
Symptom
Noise××××××× ××××××
Revision: March 2010 2008 QX56