four wheel drive INFINITI QX4 2001 Factory Service Manual

SEL683V
System Description=NBEL0228OUTLINENBEL0228S01The Navigation System (Multi-AV System) relies upon three sens-
ing devices in order to determine vehicle location at regular time
intervals.
1. Vehicle speed sensor: Determines the distance the vehicle has
traveled.
2. Gyro (Angular velocity sensor): Determines vehicle steering
angle and directional change.
3. GPS antenna (GPS data): Determines vehicle forward move-
ment and direction.
The data provided by the three sensing functions together with a
comparison of the mapping information read from the CD-ROM
drive permit accurate determination of the vehicle's current location
and subsequent course (map matching). The information appears
on a liquid crystal display.
This comparison of GPS data (vehicle position sensing) and map
matching permits precise determination of vehicle location.
SEL684V
Position Sensor Operating PrinciplesNBEL0228S0101The sensor determines current vehicle location by calculating the
previously sensed position, the distance traveled from this position,
and the directional changes occurring during this travel.
1. Distance traveled
The distance traveled is calculated using signals received from
the vehicle speed sensor. The sensor automatically compen-
sates for the slightly reduced wheel and tire diameter resulting
from tire wear.
2. Forward movement (Direction)
Changes in the direction of forward movement are calculated
by the gyro (angular velocity sensor) and the GPS antenna
(GPS data). Each of these functions has its advantage and
disadvantages. Depending upon conditions, one function takes
precedence over the other to accurately determine the direc-
tion of forward movement.
Function type Advantage Disadvantage
Gyro (Angular
velocity sen-
sor)IAble to accurately detect
minute changes in steering
angle and direction.ICalculation errors may
accumulate over a long
period of continuous
vehicle travel.
GPS antenna
(GPS data)IAble to sense vehicle travel
in four general directions
(North, South, East, and
West)IUnable to detect direction
of vehicle travel at low
vehicle speeds.
NAVIGATION SYSTEM
System Description
EL-386

SBF814E
IReplace air bag module if it has been dropped or sus-
tained an impact.
IDo not expose the air bag module to temperatures exceed-
ing 90ÉC (194ÉF).
IDo not allow oil, grease or water to come in contact with
the air bag module.
SBF239F
3. Set steering wheel in the neutral position.
4. Disconnect horn connector and remove nuts.
5. Remove dynamic damper. Then using steering wheel puller,
remove steering wheel. Be careful not to over-tighten puller
bolt on steering wheel.
CAUTION:
IDo not tap or bump the steering wheel.
6. Remove steering column cover.
SRS384
7. Unlock the spiral cable connector. Then disconnect connectors
and remove the four screws. The spiral cable can then be
removed.
CAUTION:
IDo not attempt to disassemble spiral cable.
IDo not apply lubricant to the spiral cable.
SRS276
INSTALLATIONNBRS00151. Set the front wheels in the straight-ahead position.
2. Make sure that the spiral cable is in the neutral position.
The neutral position is detected by turning left about 2.5 revo-
lutions from the right end position. Align the two marks (
).
CAUTION:
IThe spiral cable may snap due to steering operation if the
cable is installed in an improper position.
IAlso, with the steering linkage disconnected, the cable
may snap by turning the steering wheel beyond the limited
number of turns. The spiral cable can be turned to the left
about 2.5 turns from the right end position.
3. Connect spiral cable connector and tighten with screws. Install
steering column cover.
4. Install steering wheel, aligning with spiral cable pin guides, and
pull spiral cable through.
5. Connect horn connector and engage spiral cable with pawls in
steering wheel. Move air bag module connector away from
steering wheel lower lid opening.
6. Tighten nut.
: 29.4 - 39.2 N´m (3.0 - 4.0 kg-m, 22 - 28 ft-lb)
7. Install dynamic damper.
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Driver Air Bag Module and Spiral Cable (Cont'd)
RS-18