2008 INFINITI QX56 ignition

BRC-88
< ECU DIAGNOSIS >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
SIDE G-SENSOR Transverse G detected by side G sensorVehicle stopped
Approx. 0 m/s
2
Vehicle turning rightNegative value
(m/s2)
Vehicle turning left Positive value
(m/s
2)
STR ANGLE SIG Steering angle detected by steering angle
sensor Straight-ahead
Approx. 0±2.5°
Steering wheel turned –720 to +720°
PRESS SENSOR Brake fluid pressure detected by front pres-
sure sensor With ignition switch turned ON and brake
pedal released
Approx. 0 bar
With ignition switch turned ON and brake
pedal depressed –40 to 300 bar
ENGINE SPEED With engine running With engine stopped
0 rpm
Engine running Almost in accor-
dance with tachome-
ter display
FLUID LEV SW Brake fluid level switch signal status When brake fluid level switch ON
ON
When brake fluid level switch OFF OFF
FR RH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR RH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR LH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR LH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
RR RH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: March 2010 2008 QX56

BRC-90
< ECU DIAGNOSIS >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
TCS FAIL SIG TCS fail-safe signalIn TCS fail-safe ON
TCS is normal
OFF
VDC FAIL SIG VDC fail-safe signal In VDC fail-safe
ON
VDC is normal OFF
CRANKING SIG Crank operation Crank is active
ON
Crank is inactive OFF
CV1 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
CV2 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
SV1 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
SV2 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
DECEL G-SEN Longitudinal acceleration detected by Decel
G-Sensor Vehicle stopped
Approx. 0 G
Vehicle running -1.7 to 1.7 G
EBD WARN LAMP EBD warning lamp
(Note 3) When EBD warning lamp is ON
ON
When EBD warning lamp is OFF OFF
N POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = N position
ON
A/T shift position = other than N position OFF
P POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = P position
ON
A/T shift position = other than P position OFF
R POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = R position
ON
A/T shift position = other than R position OFF
2WD/4WD Drive axle 2WD model
2WD
4WD model 4WD
PRESS SEN2 Brake fluid pressure detected by rear pres-
sure sensor With ignition switch turned ON and brake
pedal released
Approx. 0 bar
With ignition switch turned ON and brake
pedal depressed –40 to 300 bar
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: March 2010 2008 QX56

EXCESSIVE ABS FUNCTION OPERATION FREQUENCYBRC-103
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
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EXCESSIVE ABS FUNCTION OPERATION FREQUENCY
Diagnosis ProcedureINFOID:0000000001686375
1.CHECK START
Check front and rear brake force di stribution using a brake tester.
Is the inspection result normal?
YES >> GO TO 2
NO >> Check brake system.
2.CHECK FRONT AND REAR AXLE
Make sure that there is no excessive play in the front and rear axles. Refer to front: FAX-6, "
On-Vehicle
Inspection and Service", Rear: RAX-6, "On-Vehicle Inspection and Service".
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair or replace malfunctioning components.
3.CHECK WHEEL SENSOR AND SENSOR ROTOR
Check the following.
• Wheel sensor installation for damage.
• Sensor rotor installation for damage.
• Wheel sensor connector connection.
• Wheel sensor harness inspection.
Is the inspection result normal?
YES >> GO TO 4
NO >> • Replace wheel sensor or sensor rotor. Refer to BRC-114, "
Removal and Installation".
• Repair harness.
4.CHECK ABS WARNING LAMP DISPLAY
Make sure that the ABS warning lamp is turned off af ter the ignition switch is turned ON or when driving.
Is the ABS warning lamp illuminated?
YES >> Perform self-diagnosis. Refer to BRC-24, "CONSULT-III Function (ABS)".
NO >> Normal
Revision: March 2010 2008 QX56

THE BRAKING DISTANCE IS LONGBRC-105
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
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THE BRAKING DISTANCE IS LONG
Diagnosis ProcedureINFOID:0000000001686377
CAUTION:
The stopping distance on slippery road surfaces might be longer with the ABS operating than when
the ABS is not operating.
1.CHECK FUNCTION
Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector to deactivate
ABS. In this condition, check stopping di stance. After inspection, connect connector.
Is the inspection result normal?
YES >> Normal
NO >> Check brake system.
Revision: March 2010 2008 QX56

BRC-106
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
ABS FUNCTION DOES NOT OPERATE
ABS FUNCTION DOES NOT OPERATE
Diagnosis ProcedureINFOID:0000000001686378
CAUTION:
ABS does not operate when speed
is 10 km/h (6 MPH) or lower.
1.CHECK ABS WARNING LAMP DISPLAY
Make sure that the ABS warning lamp turns OFF af ter ignition switch is turned ON or when driving.
Is the inspection result normal?
YES >> Normal
NO >> Perform self-diagnosis. Refer to BRC-24, "
CONSULT-III Function (ABS)".
Revision: March 2010 2008 QX56

BRC-108
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VEHICLE JERKS DURING VDC/TCS/ABS CONTROL
VEHICLE JERKS DURING
VDC/TCS/ABS CONTROL
Diagnosis ProcedureINFOID:0000000001686380
1.SYMPTOM CHECK
Check if the vehicle jerks during VDC/TCS/ABS control.
Is the inspection result normal?
YES >> Normal.
NO >> GO TO 2
2.CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis of ABS actuator and electric unit (control unit). Refer to \
BRC-24, "
CONSULT-III Func-
tion (ABS)".
Are self-diagnosis results indicated?
YES >> Check corresponding items, make repairs, and perform ABS actuator and electric unit (control
unit) self-diagnosis.
NO >> GO TO 3
3.CHECK CONNECTOR
• Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector and check
terminal for deformation, disconnection, looseness, etc.
• Securely connect connectors and perform ABS actuator and electric uni t (control unit) self-diagnosis.
Are self-diagnosis results indicated?
YES >> If poor contact, damage, open or short circuit of connector terminal is found, repair or replace.
NO >> GO TO 4
4.CHECK ECM AND TCM SELF-DIAGNOSIS RESULTS
Perform ECM and TCM self-diagnosis.
Are self-diagnosis results indicated?
YES >> Check the corresponding items. • ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
• TCM: Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
NO >> Replace ABS actuator and electric unit (control unit). Refer to BRC-116, "
Removal and Installa-
tion".
Revision: March 2010 2008 QX56

BRC-110
< PRECAUTION >[VDC/TCS/ABS]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004873045
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers , always switch the Ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000004873055
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

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