ABS NISSAN TERRANO 2004 Service Owner's Guide

WITH ABS
YBR257
BRAKE HYDRAULIC LINE
BR-7
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Bleeding Brake System
CAUTION:
ICarefully monitor brake fluid level at master cylinder dur-
ing bleeding operation.
I If master cylinder is suspected to have air inside, bleed air
from master cylinder first. Refer to ªInstallationº, ªMAS-
TER CYLINDERº, BR-17.
I Fill reservoir with recommended brake fluid ªDOT 4º. Make
sure it is full at all the times while bleeding air out of sys-
tem.
I Place a container under master cylinder to avoid spillage
of brake fluid.
I For models with ABS, turn ignition switch to the OFF posi-
tion and disconnect ABS fuse or battery cable.
I Bleed air in the following order:
Load Sensing Valve air bleeder (Models equipped with LSV)
"
Left rear brake
"
Right rear brake
"
Left front brake
"
Right front brake
1. Connect a transparent vinyl tube to air bleeder valve.
2. Fully depress brake pedal several times.
3. With brake pedal depressed, open air bleeder valve to release air.
4. Close air bleeder valve.
5. Release brake pedal slowly.
6. Repeat steps 2 through 5 until clear brake fluid comes out of air bleeder valve.
7. Tighten air bleeder valve
:7-9N ×m (0.7 - 0.9 kg-m, 61 - 78 in-lb)
SBR995
SBR419C
BRAKE HYDRAULIC LINE
BR-8
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Purpose
The Anti-lock Brake System (ABS) with an integrated Electronic Brake force Distribution (EBD) system con-
sists of electronic and hydraulic components. It allows you to control the braking force so that wheel lock can
be avoided during braking.
The advantages of ABS with EBD
1) Better tracking performance through improved steering wheel control.
2) Improved maneuverability and safer vehicle control.
3) Improved vehicle stability by preventing flat spins.
4) Shorter stopping distance and optimal utilisation of the rear brakes under many different circumstances.
Operation
IABS with EBD has self-test capabilities. The ABS warning lamp is illuminated for 1 second each time the
ignition switch is turned ªONº. After the engine is started, the ABS warning lamp turns off. An ABS self-test
is performed the first time the vehicle reaches 6 km/h (4 MPH) to ensure the system is operational. A
mechanical noise may be heard as the ABS performs this self-test and is a normal part of the self-test
feature. If a malfunction is detected during this check, the ABS warning lamp will stay on.
During the self-test, it also performs a EBD check when it detects a failure the ABS warning light will go
on simultaneously with the brake warning light and an audible sound will sound constantly.
I EBD system will only operate when the ABS is not in active status and it uses the inlet valves of ABS con-
trol unit to limit the pressure to the rear wheels when they tend to go into slip.
I When the vehicle speed is less than 10 km/h (6 MPH) the ABS system does not operate.
I While driving, a mechanical noise may be heard during ABS operation, this is a normal system condition.
ABS Hydraulic Circuit
q1Inlet solenoid valve
q
2Outlet solenoid valve
q
3Reservoir q
4Pump
q
5Motor q
6By pass check valve
q
7Damper
NBR346
ANTI-LOCK BRAKE SYSTEM
BR-38
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System Description
Sensor
The sensor unit consists of a gear-shaped sensor rotor and a sen-
sor element. The element contains a bar magnet around which a
coil is wound. The sensor is installed on the back of the brake rotor
and the rear brake drum.
As the wheel rotates, the sensor generates a sine-wave pattern.
The frequency and voltage increase(s) as the rotating speed
increases.
Control unit
The control unit computes the wheel rotating speed by the signal
current sent from the sensor. Then it supplies a DC current to the
actuator solenoid valve. It also controls ON-OFF operation of the
valve relay and rotor relay. If any electrical malfunction should be
detected in the ABS or EBD system, the control unit causes the
warning lamp(s) to light up, combined with an audible sound.
In this condition, the ABS or EBD will be deactivated by the control
unit, and the vehicle's brake system reverts to normal operation.
(Fail-safe mode)
YBR262
SBR124B
YBR263
ANTI-LOCK BRAKE SYSTEM
BR-39
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G SENSOR
The G sensor analyses deceleration during braking to determine whether the vehicle is being driven on a road
with low surface resistance () (snow-covered road, etc.). The ABS control unit uses the signal from the
deceleration sensor to compensate for road surface conditions when controlling the braking operation.
NBR136
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)BR-40
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ACTUATOR AND ELECTRIC UNIT
The actuator and electric unit contains:
IAn electric motor and pump
I Two relays
I Six solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
I ABS control unit
These components control the hydraulic circuit. The ABS control
unit directs the actuator to increase, hold or decrease hydraulic
pressure to all or individual wheels. The ABS actuator and electric
unit cannot be disassembled and has to be serviced as an assem-
bly.
YBR299
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)
BR-41
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ABS actuator operation
Inlet solenoid
valveOutlet solenoid
valve
Normal brake operation OFF (Open) OFF (Closed) Master cylinder brake fluid pressure is directly trans-
mitted to caliper via the inlet solenoid valve.
ABS operation Pressure hold ON (Closed) OFF (Closed)
Hydraulic circuit is shut off to hold the caliper brake
fluid pressure.
Pressure
decrease ON (Closed) ON (Open) Caliper brake fluid is sent to reservoir via the outlet
solenoid valve. Then it is pushed up to the master
cylinder by pump.
Pressure
increase OFF (Open) OFF (Closed) Master cylinder brake fluid pressure is transmitted to
caliper.
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)
BR-42
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Removal and Installation
CAUTION:
Be careful not to damage sensor edge and sensor rotor teeth.
When removing the front or rear wheel hub assembly, discon-
nect the ABS wheel sensor from the assembly and move it
away.
FRONT WHEEL SENSOR
REAR WHEEL SENSOR
NBR122
YBR455
ANTI-LOCK BRAKE SYSTEM
BR-43
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REAR SENSOR ROTOR
Removal
IRemove the sensor rotor using Tool.
Installation
Install the sensor rotor using suitable drift and press.
IAlways replace sensor rotor with new one.
I Pay attention to the direction of front sensor rotor as shown in
figure.
CONTROL UNIT
Location: Built-in ABS actuator.
When disconnecting the harness connector, pull the lever as
shown in figure.
G SENSOR
Always replace G sensor if bumped or dropped. Otherwise,
performance characteristics of G sensor will be changed,
which in turn alters ABS control performance characteristics.
SBR401D
SBR402D
NBR212
NBR127
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)
BR-45
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ACTUATOR
Removal
1. Disconnect battery cable.
2. Drain brake fluid. Refer to BR-5.
3. Unlock the slider then disconnect the electrical harness con-nectors from ABS control unit.
4. Identify each brake pipe with corresponding actuator port hole and mark them accordingly.
5. Disconnect brake pipes and move them away from actuator. Do not force brake pipes so as to kink them or bend them exces-
sively.
Ensure that brake fluid does not come into contact with
any parts.
YBR299
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)
BR-46
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