PRECAUTIONSBRC-5
< PRECAUTION > [VDC/TCS/ABS]
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Precaution for Brake ControlINFOID:0000000009463736
• 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.
• Sudden turns (such as spin turns, acceleration turns), drifting, etc. with VDC turned off may cause the yaw rate/side/decel G sensor to indicate a problem. This is not a problem if normal operation can be resumed
after restarting the engine.
Precaution for CAN SystemINFOID:0000000009463737
• Do not apply voltage of 7.0V or higher to terminal to be measured.
• Maximum open terminal voltage of tester in use must be less than 7.0V.
• Before checking harnesses, turn ignition switch OFF and disconnect battery negative cable.
• Area to be repaired must be soldered and wrapped with tape. Make sure that fraying of twisted wire is within 110 mm (4.33 in).
PKIA0306E
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
COMPONENT PARTSBRC-9
< SYSTEM DESCRIPTION > [VDC/TCS/ABS]
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Component DescriptionINFOID:0000000009463742
ABS Actuator and Electric Unit (Control Unit)INFOID:0000000009463743
Electric unit (control unit) is integrated with actuator and comprehensively controls VDC function, TCS func-
tion, ABS function and EBD function.
ELECTRIC UNIT (CONTROL UNIT)
• Brake fluid pressure is controlled according to signals from each sensor.
• If malfunction is detected, t he system enters fail-safe mode.
ACTUATOR
The following components are integrated with ABS actuator.
Pump
Returns the brake fluid reserved in reservoir to master cylinder by reducing pressure.
Motor
Activates the pump according to signals from ABS actuator and electric unit (control unit).
Motor Relay
Operates the motor ON/OFF according to signals fr om ABS actuator and electric unit (control unit).
Actuator Relay (Main Relay)
Operates each valve ON/OFF according to signals fr om ABS actuator and electric unit (control unit).
ABS IN Valve
Switches the fluid pressure line to increase or hold according to signals from control unit.
ABS OUT Valve
Switches the fluid pressure line to increase, hold or decrease according to signals from control unit.
Cut Valve 1, Cut Valve 2
Shuts off the ordinary brake line from master cylinder, when VDC function and TCS function are activated.
7. Rear wheel sensor LH (RH similar) 8. VDC OFF switch 9. Steering angle sensor
(view with steering wheel removed)
10. Parking brake switch 11. Stop lamp switch 12. Combination meter
Component Reference/Function
ABS actuator and electric unit (control unit) BRC-9, "ABS Actuator and Electric Unit (Control Unit)"
Wheel sensorBRC-10, "Wheel Sensor and Sensor Rotor"
Stop lamp switchBRC-10, "Stop Lamp Switch"
Steering angle sensorBRC-10, "Steering Angle Sensor"
Vacuum sensorBRC-10, "Vacuum Sensor"
VDC OFF switchBRC-11, "VDC OFF Switch"
Brake fluid level switchBRC-10, "Brake Fluid Level Switch"
Parking brake switchBRC-11, "Parking Brake Switch"
ABS warning lamp
BRC-12, "VDC/TCS/ABS : System Description"
Brake warning lamp
VDC OFF indicator lamp
SLIP indicator lamp
ECM Transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
• Accelerator pedal position signal
• Engine speed signal
• Target throttle position signal
TCM Transmits the current gear position signal
to ABS actuator and electric unit (control
unit) via CAN communication.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-10
< SYSTEM DESCRIPTION >[VDC/TCS/ABS]
COMPONENT PARTS
Suction Valve 1, Suction Valve 2
Supplies the brake fluid from master cylinder to t
he pump, when VDC function and TCS function are activated.
Return Check Valve
Returns the brake fluid from brake caliper and wheel cy linder to master cylinder by bypassing orifice of each
valve when brake is released.
Reservoir
Temporarily reserves the brake fluid drained from brake caliper, so that pressure efficiently decreases when
decreasing pressure of brake caliper and wheel cylinder.
Yaw rate/side/decel G sensor
Calculates the following information that affects the vehicle, and transmits a signal to ABS actuator and elec-
tric unit (control unit) via communication lines.
• Vehicle rotation angular velocity (yaw rate signal)
• Vehicle lateral acceleration (side G signal) and longitudinal acceleration (decel G signal)
Pressure Sensor
Detects the brake fluid pressure and transmits signal to ABS actuator and electric unit (control unit).
Wheel Sensor and Sensor RotorINFOID:0000000009463744
NOTE:
• Wheel sensor of front wheel is installed on steering knuckle.
• Sensor rotor of front wheel is integrated in wheel hub assembly.
• Wheel sensor of rear wheel is installed on back plate of rear brake.
• Sensor rotor of rear wheel is installed on rear brake drum.
• Never measure resistance and voltage value using a tester because sensor is active sensor.
• Downsize and weight reduction is aimed. IC for detection portion and magnet for sensor rotor are adopted.
• Power supply is supplied to detection portion so that magnetic field line is read. Magnetic field that is detected is converted to current
signal.
• When sensor rotor rotates, magnetic field changes. Magnetic field change is converted to current signals (rectangular wave) and is
transmitted to ABS actuator and el ectric unit (control unit). Change
of magnetic field is proportional to wheel speed.
Stop Lamp SwitchINFOID:0000000009463745
Detects the operation status of brake pedal and transmits converted electric signal to ABS actuator and elec-
tric unit (control unit).
Steering Angle SensorINFOID:0000000009463746
Detects the following information and transmits steering angl e signal to ABS actuator and electric unit (control
unit) via CAN communication.
• Steering wheel rotation amount
• Steering wheel rotation angular velocity
• Steering wheel rotation direction
Brake Fluid Level SwitchINFOID:0000000009463747
Detects the brake fluid level in reservoir tank and transmi ts converted electric signal from combination meter to
ABS actuator and electric unit (control unit) via CAN communication.
Vacuum SensorINFOID:0000000009463748
Detects the vacuum in brake booster and transmits conver ted electric signal to ABS actuator and electric unit
(control unit).
JPFIC0131GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMBRC-23
< SYSTEM DESCRIPTION > [VDC/TCS/ABS]
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VDC/TCS/ABS : VDC FunctionINFOID:0000000009463753
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
• Side slip or tail slip may occur while driving on a slippery road or intending an urgent evasive driving maneu- ver. VDC function detects side slip status using each s ensor when side slip or tail slip is about to occur and
improves vehicle stability by brake c ontrol and engine output control during driving.
• In addition to ABS function, EBD function and TCS functi on, target side slip amount is calculated according
to steering operation amount from steering angle sensor. By comparing this information with vehicle side slip
amount that is calculated from information from yaw rate/side G sensor and wheel sensor, vehicle driving
conditions (conditions of understeer or oversteer) are judged and vehicle stability is improved by brake force
control on all 4 wheels and engine output control.
• VDC function can be switched to non-operational status (OFF) by operating VDC OFF switch. In this case,
VDC OFF indicator lamp turns ON.
• Control unit portion automatically improves driving st ability by performing brake force control as well as
engine output control, by transmitting drive signal to actuator portion according to difference between target
side slip amount and vehicle side slip amount
Brake limited slip differential (BLSD) function
is malfunctioning OFF OFF
VDC function is operating OFF OFF
TCS function is operating OFF OFF Condition (status) ABS warnin
g lamp Brake warning lamp
ALFIA0298GB
JSFIA0672GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-24
< SYSTEM DESCRIPTION >[VDC/TCS/ABS]
SYSTEM
• Brake force control function
at braking hard detects driver′s brake operations with the pressure sensor,
judges a brake booster ′s maximum brake power function by using information from the vacuum sensor, and
enhances more powerful braking force by controlling brakes of four wheels.
• VDC warning lamp blinks while VDC function is in operati on and indicates to the driver that the function is in
operation.
• CONSULT can be used to diagnose the system.
• Fail-safe function is adopted. When a malfunction occurs in VDC function, the control is suspended for VDC
function and TCS function. However, ABS functi on and EBD function operate normally. Refer to BRC-41,
"Fail-safe".
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
OPERATION CHARACTERISTICS
VDC Function That Prevents Oversteer Tendency
• During cornering, brake force (brake fluid pressu re) is applied on front wheel and rear wheel on the outer
side of turn. Momentum is generated directing the vehicle toward the outer side of the turn. Oversteer is pre-
vented.
• Changing driving lane on a slippery road, when there may be a tendency to oversteer, engine output is con- trolled as well as brake force (brake fluid pr essure) of 4 wheels. Oversteer tendency decreases.
Component Signal description
ECM Transmits the following signals to ABS actuator and electric unit (control unit) via CAN commu-
nication.
• Acceleration pedal position signal
• Engine speed signal
• Target throttle position signal
TCM Transmits the current gear positi
on signal to ABS actuator and el ectric unit (control unit) via
CAN communication.
Steering angle sensor Transmits the steering angle sensor signal to ABS actuator and electric unit (control unit) via
CAN communication.
Combination meter Transmits the following signals to ABS actuator and electric unit (control unit) via CAN commu-
nication.
• Brake fluid level switch signal
• parking brake switch signal
Receives the following signals from ABS actuator and electric unit (control unit) via CAN com-
munication.
• VDC OFF indicator lamp signal
• SLIP indicator lamp signal
ALFIA0339GB
ALFIA0340GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-26
< SYSTEM DESCRIPTION >[VDC/TCS/ABS]
SYSTEM
• Wheel spin status of drive wheel is detected by wheel sensor of 4
wheels. Engine output and transmission shift status is controlled
so that slip rate of drive wheels is in appropriate level. When wheel
spin occurs on drive wheel, ABS actuator and electric unit (control
unit) perform brake force control of LH and RH drive wheels (apply
brake force by increasing brake fluid pressure of drive wheel) and
decrease engine torque by engine torque control. Wheel spin
amount decreases. Engine torque is controlled to appropriate
level.
• TCS function can be switched to non-operational status (OFF) by operating VDC OFF switch. In this case, VDC OFF indicator lamp
turns ON.
• SLIP indicator lamp blinks while TCS function is in operation and
indicates to the driver that the function is in operation.
• CONSULT can be used to diagnose the system.
• Fail-safe function is adopted. When a malfunction occurs in TCS
function, the control is sus pended for VDC function and TCS func-
tion. However, ABS function and EBD function operate normally.
Refer to BRC-41, "Fail-safe"
.
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
JPFIC0139GB
Component Signal description
ECM Transmits the following signals to ABS actuator and electric unit (control unit) via CAN commu-
nication.
• Accelerator pedal position signal
• Engine speed signal
• Target throttle position signal
TCM Transmits the current gear positi
on signal to ABS actuator and el ectric unit (control unit) via
CAN communication.
Steering angle sensor Transmits the steering angle sensor signal to ABS actuator and electric unit (control unit) via
CAN communication.
Combination meter Transmits the following signals to ABS actuator and electric unit (control unit) via CAN commu-
nication.
• Brake fluid level switch signal
• Parking brake switch signal
Receives the following signals from ABS actuator and electric unit (control unit) via CAN com-
munication.
• VDC OFF indicator lamp signal
• SLIP indicator lamp signal
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMBRC-27
< SYSTEM DESCRIPTION > [VDC/TCS/ABS]
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VDC/TCS/ABS : ABS FunctionINFOID:0000000009463755
SYSTEM DIAGRAM
• By preventing wheel lock through brake force (brake flui d pressure) control that is electronically controlled by
detecting wheel speed during braking, stability during em ergency braking is improved so that obstacles can
be avoided by steering operation.
• During braking, control units calculate wheel speeds , and transmit pressure increase, hold or decrease sig-
nals to actuator portion according to wheel slip status.
• The following effects are obtained by preventing wheel lock during braking.
- Vehicle tail slip is prevented during braking when driving straight.
- Understeer and oversteer tendencie s are moderated during brak-
ing while cornering.
- Obstacles may be easily bypassed by steering operation during
braking.
• CONSULT can be used to diagnose the system.
• Fail-safe function is adopted. When a malfunction occurs in ABS
function, the control is suspended for VDC function, TCS function
and ABS function. However, EBD function operates normally.
Refer to BRC-29, "VDC/TCS/ABS : Fail-safe"
.
INPUT SIGNAL AND OUTPUT SIGNAL
ALFIA0297GB
JPFIC0140GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
BRC-40
< ECU DIAGNOSIS INFORMATION >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
R POSI SIGTransmission range switch signal ON/OFF
condition CVT shift position = R position On
CVT shift position = other than R position Off
N POSI SIG Transmission range switch signal ON/OFF
condition CVT shift position = N position On
CVT shift position = other than N position Off
P POSI SIG Transmission range switch signal ON/OFF
condition CVT shift position = P position On
CVT shift position = other than P position Off
ACCEL POS SIG Throttle actuator opening/closing is dis-
played (linked with accelerator pedal) Accelerator pedal not depressed (ignition
switch is ON) 0 %
Depress accelerator pedal (ignition
switch is ON) 0 - 100 %
SIDE G-SENSOR Transverse G detected by side G sensor Vehicle 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
°
Steering wheel turned –720 to 720 °
PRESS SENSOR Brake fluid pressure detected by pressure
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
EBD SIGNAL EBD operation EBD is active On
EBD is inactive Off
ABS SIGNAL ABS operation ABS is active On
ABS is inactive Off
TCS SIGNAL TCS operation TCS is active On
TCS is inactive Off
VDC SIGNAL VDC operation VDC is active On
VDC is inactive Off
EBD FAIL SIG EBD fail-safe signal In EBD fail-safe On
EBD is normal Off
ABS FAIL SIG ABS fail-safe signal In ABS fail-safe On
ABS is normal Off
TCS FAIL SIG TCS fail-safe signal In 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
FLUID LEV SW Brake fluid level switch When brake fluid level switch ON On
When brake fluid level switch OFF Off
PARK BRAKE SW Parking brake switch Parking brake switch is active On
Parking brake switch is inactive Off
Monitor item Display content
Data monitor
Condition Reference value in
normal operation
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM