1998 NISSAN PICK-UP lock

System Components
System Description
WHEEL SENSOR
The sensor unit consists of a gear-shaped sensor rotor and a
sensor 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 front of the differential (2WD) or the back of
the rear brake drum (4WD). As the wheel rotates, the sensor
generates a sine-wave pattern. The frequency and voltage
increase(s) as the rotating speed increases.
CONTROL UNIT (built in ABS actuator and electric
unit)
The control unit computes the wheel rotating speed by the sig-
nal 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 motor relay. If any electrical malfunction
should be detected in the system, the control unit causes the
warning lamp to light up. In this condition, the ABS will be deac-
tivated by the control unit, and the vehicle's brake system reverts
to normal operation. (For control unit layout, refer to ABS
ACTUATOR AND ELECTRIC UNIT, BR-34.)
SBR068E
SBR069E
ANTI-LOCK BRAKE SYSTEM
BR-33

G SENSOR (4WD models only)
The G sensor senses deceleration during braking to determine whether the vehicle is being driven on a high
 road (asphalt road, etc.) or a low  road (snow-covered road, etc.). It then sends a signal to the ABS con-
trol unit.
The reed switch turns on when it is affected by a magnetic field. During sudden deceleration (braking on a
high  road), the weight moves and the magnet in the weight moves away from the reed switch. The mag-
netic field then diminishes and the reed switch turns off.
ABS ACTUATOR AND ELECTRIC UNIT
The ABS actuator and electric unit contains:
lAn electric motor and pump
lTwo relays
lSix solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
lABS control unit
This component controls the hydraulic circuit and increases,
holds or decreases hydraulic pressure to all or individual wheels.
The ABS actuator and electric unit are not disassemble.
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 wheel cylinder via the inlet solenoid valve.
ABS operationPressure hold ON (Closed) OFF (Closed)Hydraulic circuit is shut off to hold the wheel cylinder
brake fluid pressure.
Pressure
decreaseON (Closed) ON (Open)Wheel cylinder brake fluid is sent to reservoir via the
outlet solenoid valve. Then it is pushed up to the
master cylinder by pump.
Pressure
increaseOFF (Open) OFF (Closed)Master cylinder brake fluid pressure is transmitted to
wheel cylinder.
SBR070E
SBR071E
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)
BR-34

Removal and Installation
CAUTION:
Be careful not to damage sensor edge and sensor rotor
teeth.
When removing the front wheel hub or rear axle shaft
assembly, disconnect the ABS wheel sensor from the
assembly and move it away.
FRONT WHEEL SENSOR
SBR311E
ANTI-LOCK BRAKE SYSTEM
BR-35

REAR WHEEL SENSOR
SBR073E
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)
BR-36

G SENSOR
Always replace G sensor if bumped or dropped. Otherwise,
performance characteristics of G sensor will be changed,
which in turn changes ABS control performance character-
istics.
ABS ACTUATOR AND ELECTRIC UNIT
Removal
1. Disconnect battery cable.
2. Drain brake fluid. Refer to ``Changing Brake Fluid'', BR-3.
3. Remove mounting bracket fixing bolts and nuts.
4. Disconnect connector, brake pipes and remove fixing nuts.
Installation
CAUTION:
After installation, refill brake fluid. Then bleed air. Refer to
``Bleeding Brake System'', BR-4.
1. Connect brake pipes temporarily.
2. Tighten fixing bolts and nuts.
3. Tighten brake pipes.
4. Connect connector and battery cable.
SBR074E
SBR075E
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)
BR-37

Clutch Disc and Flywheel
INSPECTION
lCheck clutch disc for burns, discoloration or oil or grease
leakage. Replace if necessary.
lCheck clutch disc for wear of facing.
Wear limit of facing surface to rivet head:
0.3 mm (0.012 in)
lCheck clutch disc for backlash of spline and runout of facing.
Maximum backlash of spline (at outer edge of disc):
240 1.0 mm (0.039 in)
250 1.0 mm (0.039 in)
Runout limit:
0.7 mm (0.028 in) TD25 engine
1.0 mm (0.039 in) Except TD25 engine
Distance of runout check point (from hub center):
240 115 mm (4.53 in)
250 120 mm (4.72 in)
lCheck flywheel and clutch disc contact surface for slight
burns or discoloration. Repair flywheel with emery paper.
lCheck flywheel runout.
Maximum allowable runout:
Refer to EM section (``Inspection'', ``CYLINDER
BLOCK'').
SCL206
SCL229-A
SCL221-A
SEM929A
CLUTCH DISC AND CLUTCH COVER
CL-12

Body Front End
lWhen removing or installing hood, place a cloth or other padding on hood. This prevents vehicle body
from being scratched.
lBumper fascia is made of plastic. Do not use excessive force and be sure to keep oil away from it.
lHood adjustment: Adjust at hinge portion.
lHood lock adjustment: After adjusting, check hood lock control operation. Apply a coat of grease to hood
locks engaging mechanism.
lHood opener: Do not attempt to bend cable forcibly. Doing so increases effort required to unlock hood.
REMOVAL Ð Front bumper assembly
V1Remove screws securing left and right combination lamps and remove the lamps.
V2Remove clips securing front grille and remove the front grille.
V3Remove bolts securing left and right bumper stays.
V4Remove bolts securing left and right bumper side brackets.
V5Remove bolts securing left and right bumper side stays.
V6Extract bumper assembly.
BODY END
BT-5

Body Rear End
lAdjustment: Adjust at hinge portion for proper fit.
lLock system adjustment: Adjust striker so that it is in the center of the lock. After adjustment, check trunk
lid lock operation.
lAfter installation, make sure that rear gate opens smoothly.
REMOVAL Ð Rear bumper assembly
V1Remove connectors securing license plate lamps.
V2Remove nuts securing bumper side stay.
V3Extract bumper assembly.
SBT429
BODY END
BT-8