2008 INFINITI QX56 engine

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-100
< ECU DIAGNOSIS >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
In case of an electrical malfunction with the ABS, t
he ABS warning lamp, VDC OFF indicator lamp and SLIP
indicator lamp will turn on. In case of an electrical malfunction with the EBD system, the BRAKE warning lamp,
ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp will turn on.
The system will revert to one of the follo wing conditions of the Fail-Safe function.
1. For ABS malfunction, only the EBD is operative and the condition of the vehicle is the same condition of vehicles without ABS/TCS/VDC system.
2. For EBD malfunction, the EBD and ABS become inoperat ive, and the condition of the vehicle is the same
as the condition of vehicles without ABS/TCS/VDC or EBD system.
VDC/TCS SYSTEM
In case of TCS/VDC system malfunction, the VDC OFF indicator lamp and SLIP indicator lamp are turned on
and the condition of the vehicle is the same as the c ondition of vehicles without TCS/VDC system. In case of
an electrical malfunction with the TCS/VDC system, the ABS control continues to operate normally without
TCS/VDC control.
DTC No. IndexINFOID:0000000001686373
DTC Items (CONSULT screen terms) Reference
C1101 RR RH SENSOR-1
BRC-29, "
Description"C1102RR LH SENSOR-1
C1103 FR RH SENSOR-1
C1104 FR LH SENSOR-1
C1105 RR RH SENSOR-2
BRC-32, "
Description"C1106RR LH SENSOR-2
C1107 FR RH SENSOR-2
C1108 FR LH SENSOR-2
C1109 BATTERY VOLTAGE [ABNORMAL] BRC-35, "
Description"
C1110CONTROLLER FAILURE BRC-37, "DTC Logic"
C 1111P U M P M O T O R BRC-38, "Description"
C1113G-SENSOR BRC-40, "Description"
C1115ABS SENSOR [ABNORMAL SIGNAL] BRC-43, "Description"
C1116STOP LAMP SW BRC-46, "Description"
C1120FR LH IN ABS SOL BRC-48, "Description"
C1121FR LH OUT ABS SOL BRC-51, "Description"
C1122FR RH IN ABS SOL BRC-48, "Description"
C1123FR RH OUT ABS SOL BRC-51, "Description"
C1124RR LH IN ABS SOL BRC-48, "Description"
C1125RR LH OUT ABS SOL BRC-51, "Description"
C1126RR RH IN ABS SOL BRC-48, "Description"
C1127RR RH OUT ABS SOL BRC-51, "Description"
C1130ENGINE SIGNAL 1
BRC-54, "
Description"
C1131ENGINE SIGNAL 2
C1132 ENGINE SIGNAL 3
C1133 ENGINE SIGNAL 4
C1136 ENGINE SIGNAL 6
C1140 ACTUATOR RLY BRC-56, "
Description"
C1142PRESS SEN CIRCUIT BRC-58, "Description"
C1143ST ANG SEN CIRCUIT
BRC-61, "Description"C1144ST ANG SEN SIGNAL
Revision: March 2010 2008 QX56

BRC-102
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VDC/TCS/ABS
SYMPTOM DIAGNOSIS
VDC/TCS/ABS
Symptom TableINFOID:0000000001686374
If ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn ON, perform self-diagnosis.
NOTE:
• 1: The ABS does not operate when the speed is 10 km/h (6 MPH) or less.
• 2: Under the following conditions, ABS is activated and vibration is felt when brake pedal is lightly depressed. However, this
is normal.
- When shifting gears
- When driving on slippery road
- During cornering at high speed
- When passing over bumps or grooves [at approximately 50 mm (1.97 in) or more]
- When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher] Symptom
Check itemReference
Excessive ABS function operation fre-
quency Brake force distribution
BRC-103, "
Diag-
nosis Procedure"Looseness of front and rear axle
Wheel sensor and rotor system
Unexpected pedal reaction Brake pedal stroke
BRC-104, "
Diag-
nosis Procedure"Make sure the braking force is sufficient when the ABS is not operating.
The braking distance is long Check stopping distance when the ABS is not operating. BRC-105, "
Diag-
nosis Procedure"
ABS function does not operate (Note 1) ABS actuator and electric
unit (control unit)BRC-106, "Diag-
nosis Procedure"
Pedal vibration or ABS operation sound
occurs (Note 2)Brake pedal
BRC-107, "Diag-
nosis Procedure"ABS actuator and electric unit (control unit)
Vehicle jerks during VDC/TCS/ABS con-
trol ABS actuator and electric unit (control unit)
BRC-108, "
Diag-
nosis Procedure"TCM
ECM
Revision: March 2010 2008 QX56

PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
BRC-107
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
Diagnosis ProcedureINFOID:0000000001686379
CAUTION:
Under the following conditions, ABS is activated an d vibration is felt when brake pedal is lightly
depressed. However, this is normal.
• When shifting gears
• When driving on slippery road
• During cornering at high speed
• When passing over bumps or grooves [at approximately 50 mm (1.97 in) or more]
• When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher]
1.SYMPTOM CHECK 1
Check that there are pedal vibrat ions when the engine is started.
Do vibrations occur?
YES >> GO TO 2
NO >> Inspect the brake pedal.
2.SYMPTOM CHECK 2
Check that there are ABS operation noises when the engine is started.
Do the operation noises occur?
YES >> GO TO 3
NO >> Perform self -diagnosis. Refer to BRC-24, "
CONSULT-III Function (ABS)".
3.SYMPTOM CHECK 3
Check symptoms when electrical component (headlamps, etc.) switches are operated.
Do symptoms occur?
YES >> Check if there is a radio, antenna, antenna lead wire, or wiring close to the control unit. If there is,
move it farther away.
NO >> Normal
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

NORMAL OPERATING CONDITIONBRC-109
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001686381
Symptom Result
Slight vibrations are felt on the brake pedal and the operation noises occur, when VDC, TCS or ABS is acti-
vated. This is a normal condi-
tion due to the VDC,
TCS or ABS activation.
Stopping distance is longer than that of vehicles without ABS when the vehicle drives on rough, gravel, or
snow-covered (fresh, deep snow) roads.
The brake pedal moves and generates noises, when TCS or VDC is activated due to rapid acceleration or
sharp turn.
The brake pedal vibrates and motor operation noises occur from the engine room, after the engine starts and
just after the vehicle starts. This is normal, and it is
caused by the ABS op-
eration check.
Depending on the road conditions, the driver may experience a sluggish feel. This is normal, because
TCS places the highest
priority on the optimum
traction (stability).
TCS may activate momentarily if wheel speed changes when driving over location where friction coefficient
varies, when downshifting, or when fully depressing accelerator pedal.
The ABS warning lamp, VDC OFF indicato
r 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 rotating on a turntable or located on
a ship while the engine is running. In this case, restart the
engine on a normal
road. If the normal con-
dition is restored, there
is no malfunction. At
that time, erase the self-
diagnosis memory.
VDC may not operate normally or the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp
may illuminate, when running on a special road that is extremely slanted (e.g. bank in a circuit course).
A malfunction may occur in the yaw rate/side/decel G sensor system, when the vehicle turns sharply, such
as during a spin turn, axle turn, or drift driving, while the VDC function is off (VDC OFF indicator lamp illumi-
nated).
The vehicle speed will not increase even though the accelerator pedal is depressed, when inspecting the
speedometer on a 2-wheel chassis dynamometer.
Normal (Deactivate the
VDC/TCS function be-
fore performing an in-
spection on a chassis
dynamometer.)
VDC OFF indicator lamp and SLIP indicator lamp may simultaneously turn on when low tire pressure warn-
ing lamp turns on. This is not a VDC sys-
tem error but results
from characteristic
change of tire.
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]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
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