'99camry U
205
Tire surface and wheel nuts
Check the tires carefully for cuts, damage
or excessive wear. See Chapter 7±2 for
additional information. When checking the
tires, make sure no nuts are missing, and
check the nuts for looseness. Tighten
them if necessary.
Tire rotation
Rotate the tires every 12000 km (7500
miles). See Chapter 7±2 for additional in-
formation.
Fluid leaks
Check underneath for leaking fuel, oil, wa-
ter or other fluid after the vehicle has
been parked for a while. If you smell fuel
fumes or notice any leak, have the cause
found and corrected immediately.
Doors and engine hood
Check that all doors including trunk lid
operate smoothly and all latches lock se-
curely. Make sure the engine hood sec-
ondary latch secures the hood from open-
ing when the primary latch is released.
INSIDE THE VEHICLE
Items listed below should be checked
regularly, e.g. while performing periodic
services, cleaning the vehicle, etc.Lights
Make sure the headlights, stop lights, tail
lights, turn signal lights, and other lights
are all working. Check headlight aim.
Service reminder indicators and warning
buzzers
Check that all service reminder indicators
and warning buzzers function properly.
Steering wheel
Be alert for changes in steering condition,
such as hard steering or strange noise.
Seats
Check that all front seat controls such as
seat adjusters, seatback recliner, etc. op-
erate smoothly and that all latches lock
securely in any position. Check that the
head restraints move up and down
smoothly and that the locks hold securely
in any latched position. For folding±down
rear seatbacks, check that the latches
lock securely.
Seat belts
Check that the seat belt system such as
buckles, retractors and anchors operate
properly and smoothly. Make sure that the
belt webbings not cut, frayed, worn or
damaged.Accelerator pedal
Check the pedal for smooth operation and
uneven pedal effort or catching.
Clutch pedal
Check the pedal for smooth operation.
Brake pedal
Check the pedal for smooth operation and
that the pedal has the proper clearance.
Check the brake booster function.
Brakes
At a safe place, check that the brakes do
not pull to one side when applied.
Parking brake
Check that the lever has the proper travel
and that, on a safe incline, your vehicle
is held securely with only the parking
brake applied.
Automatic transmission ºParkº mecha-
nism
Check the lock release button of the se-
lector lever for proper and smooth opera-
tion. On a safe incline, check that your
vehicle is held securely with the selector
lever in ºPº position and all brakes re-
leased.
GENERAL 1999 FEATURES
160GE06 160GE05
Normal Condition Activated Condition Stationary
Contact PointRotor
Movable
Contact
PointDeceleration
141BE65 148BO127Corolla
Fig. 1
Fig. 2Range of Operation
Front Airbag
Sensor ON / OFF
Safing Sensor
ON
Airbag Sensor
ONAND
Ignition
6
4. Construction and Operation
Front Airbag Sensor
The front airbag sensor consists of rotor, movable contact point and a stationary contact point.
The rotor is fixed by the initial set load of the movable contact point. At the same time, the movable contact
point restrains the movement of the rotor which is generated during vehicle deceleration, thus preventing
the unintended activation of the system.
If a sudden deceleration that exceeds a predetermined value occurs due to a collision of the vehicle, the rotor
will rotate. The rotational movement of the rotor pushes the movable contact point and causes the movable
and stationary contact points to come into contact. As a result, an ON signal is generated and transmitted
to the airbag sensor assembly.
5. System Operation
Ignition Judgement and Condition
When the vehicle collides in the hatched area (Fig. 1) and the shock is larger than a predetermined level,
the airbag and the seat belt pretensioner are activated automatically. The airbag sensor is characteristically
turned in such a way that can judge the need for ignition in collisions within the hatched area.
The safing sensor is designed to be activated by a smaller deceleration rate than that of the airbag sensor.
As illustrated in Fig. 2 below, ignition is operated when current flows to the squib. This happens when a
safing sensor and the airbag sensor go on simultaneously.
Airbag sensor assembly judges whether or not to inflate the airbag in accordance with ON / OFF of the front
airbag sensor and the deceleration detected by the airbag sensor.
GENERAL 1999 FEATURES
160GE01
Radio and Cassette DeckCommunication BusCD Changer
Physical Address : 190
Logical Address : 11 (Mode Control)
25 (Command Switch)
60 (Radio Tuner)
61 (Cassette Deck)Physical Address: 240
Logical Address: 43 10
2. Communication Outline
In the audio system that uses AVC-LAN, audio units such as a cassette deck or a CD changer are connected
by a communication bus that establishes communication via serial data signals.
In this system, addresses are used to identify the units with which to establish communication. The addresses
can be broadly divided into two types: the physical address that is assigned to each audio unit such as a cas-
sette deck, CD changer, etc.; and the logical address that is assigned to the function that each unit provides,
such as the radio function or the cassette function. The physical addresses are represented by 3-digit numbers
and the logical addresses are represented by 2-digit numbers.
The signals that are exchanged between the units are the unit's control signal, display data, audio signal, etc.,
which have been rendered into serial data. The configuration of the 4 signals indicated below, which are ren-
dered into serial data and transmitted to the each unit, has been established as a uniform AVC-LAN standard.
Audio Signal
Video Signal
Display Data
Signal Communication Software
The illustration below shows an example of an audio system configuration using AVC-LAN.
3. Operation
System Registration
An audio system that uses AVC-LAN performs a registration process to verify the audio units that comprise
the system.
When the ignition switch is turned to the ACC position, the audio units that comprise the system transmit
the logic address in the units, and the physical address is transmitted by the mode control portion that is
integrated in the smallest audio unit (head unit). By receiving these addresses, the mode control portion veri-
fies the units that comprise the system.
By performing this process, all functions can be controlled regardless of the combination of the units that
comprise the system.
1
GENERAL 1999 FEATURES
160GE02
160GE03
MUTE
Sound
VOL
74
ICIC
Cassette
61Radio
60ICCD
Changer
43
Power Amplifier
Power Supply
Control
Mode ControlCommand
SwitchVolume Cassette Radio
Fig. 1
CD Changer
OFF
CD
Radio
CD
Play Notice
Output ON Request
Output ON Verification
Output OFF Verification
Output ON VerificationOutput ON Request Amplifier Power
Supply ON
Power On Notice Output ON Verification Output ON Instruction
Output ON Instruction
Output ON Instruction Output OFF Instruction
Radio ONCD OFFCD ON
AMFM
Fig. 2
(Shielded)
(Press Switch)
(Press Switch)
11
Switching the System
An audio system that uses AVC-LAN consists of audio units that are connected in parallel as described in
Fig. 1. Each of the audio units has a switch to connect the unit to the communication bus.
To control the audio units in accordance with the system to be operated, the mode control portion transmits
output ON and output OFF instructions. In accordance with the instruction signals transmitted by the mode
control portion, the units turn their switches ON or OFF to switch the operating unit and system. Fig. 2 shows
an example of a signal exchange that takes place between the mode control unit and each audio unit during
the switching of the system.
NF
NEW FEATURES Ð 5S-FNE ENGINE19
ENGINE CONTROL SYSTEM
1. General
An engine control system based on the 5S-FE engine has been adopted. The knock sensor has been discontin-
ued because natural gas has a high octane value and is less susceptible to knocking.
The engine control system of 5S-FNE and 5S-FE engines are compared below.
System
Outline5S-FNE5S-FE
SFI
Sequential
A D-type SFI system is used, which indirectly detects
intake air volume by manifold absolute pressure sensor.
Sequential
Multiport Fuel
Injection
The fuel injection system is a sequential multiport fuel
injection system.
Ignition timing is determined by the ECM based on sig-
nals from various sensors.
ESA
Electronic Spark
AdvanceThe ECM corrects the ignition timing in response to en-
gine knocking in accordance with the signals received
from the knock sensor.
Ð
Advance
Torque control correction during gear shifting had been
used to minimize the shift shock.*1
IAC
(Idle Air Control)A rotary solenoid type IAC valve controls the fast idle
and idle speeds.
(1-Coil Type
Built-in Driver)(2-Coil Type)
Fuel Pump ControlFuel pump operation is controlled by signal from the
ECM.Ð
Fuel Cut-Off
Control
The fuel shutoff valves for the fuel tank, fuel pressure
regulator, and delivery pipe are shut off to stop the sup-
ply of fuel when the ignition switch is turned OFF or
during abnormal conditions (such as engine stalling,
SRS airbag deployed, etc.).
Ð
Oxygen Sensor
and Air Fuel Ratio
Sensor
Heater ControlMaintains the temperature of the oxygen sensor and air
fuel ratio sensor at an appropriate level to increase accu-
racy of detection of the oxygen concentration in the ex-
haust gas.
*2
EGR Cut-Off
ControlCuts off EGR according to the engine condition to
maintain drivability of the vehicle and durability of the
EGR components.
Evaporative
Emission ControlThe ECM controls the purge flow of evaporative emis-
sions (HC) in the charcoal canister in accordance with
engine conditions.
Ð
Air Conditioning
Cut-Off ControlBy turning the air conditioning compressor ON or OFF
in accordance with the engine condition, drivability is
maintained.
*3*3
When the ECM detects a malfunction, the ECM diag-
noses and memorized the failed section.
DiagnosisThe diagnosis system includes a function that detects a
malfunction in the evaporative emission control sys-
tem.
Ð
Fail-Safe
When the ECM detects a malfunction, the ECM stops
or controls the engine according to the data already
stored in memory.
*1: Only for Automatic Transaxle Model
*
2: Air fuel ratio sensor only for California specification model.
*
3: The air conditioning magnet clutch controled by the ECM
B HOW TO USE THIS MANUAL
The ground points circuit diagram shows the connections from all major parts to the respective ground points. When
troubleshooting a faulty ground point, checking the system circuits which use a common ground may help you identify
the problem ground quickly. The relationship between ground points (
EA, IB and IC shown below) can also be
checked this way.
I GROUND POINT
FAN MAIN RELAY
FAN MAIN RELAY
A/C FAN RELAY NO.2
A/C FAN RELAY NO.3
RADIATOR FAN MOTOR
RETRACT CONTROL
RELAY
RETRACT MOTOR RH
RETRACT MOTOR LH
FRONT TURN SIGNAL
LIGHT RH
PARKING LIGHT RH
FRONT TURN SIGNAL
LIGHT LH
PARKING LIGHT LH
DOOR LOCK CONTROL
SW RH
DOOR KEY LOCK
SW RH
DOOR LOCK MOTOR
RH
BLOWER RESISTOR
A/C AMPLIFIER
RADIO AND PLAYER
HEATER RELAY
AUTO ANTENNA
MOTOR
BLOWER SW
PARKING BRAKE SW
COMBINATION METER
HORN SW [COMB. SW]
TURN SIGNAL FLASHER
DOOR KEY LOCK SW LH
DOOR LOCK MOTOR LH
FUEL CONTROL SW
WOOFER AMPLIFIER
COMBINATION METER
COMBINATION METER
FUEL SENDER
CIGARETTE LIGHTER
O/D MAIN SW
CLOCK
5
5
5
5
4
4
4
4
4BA15
IB18
EA2 10
3E5
3E
6 3G
13 3F
3 3D
1 3B
7
ID115
IC33
IA12
E 3
A
A AW±B
W±BW±B W±B
W±B W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B W±BW±B W±B W±B W±B
W±B W±B
W±BW±B
W±B
W±B
W±B W±B
W±B
BR
W±B
BR BRW±BW±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B W±B
W±B
W±B
W±B
W±B
BR W±B
BR BR
BR W±B W±BW±B
W±BW±BBR W±B (4A±GZE)
W±B A A A
I 6
I 6
I 2
I 2
I 2
B 5I 5
I 5
I 5
B 5
B 5
B 5
I 5
I 5
I 3I 3
E 3
E 3
E 3
E 2
E 4
E 5
E 4
E 5
E 6E 4
E 4
B 4
EAI 4
B 4
B 4
I 4I 8
IBIC
3C7
4
JUNCTION
CONNECTOR J 1
4
DOOR LOCK CONTROL
RELAY
ELECTRICAL IDLE-UP
CUT RELAY (M/T)FRONT SIDE MARKER
LIGHT RH
FRONT SIDE MARKER
LIGHT LH
BRAKE FLUID LEVEL
WARNING SW
UNLOCK WARNING
SW WIPER AND WASHER
SW [COMB. SW] LIGHT CONTROL SW
[COMB. SW] HEATER CONTROL
ASSEMBLY
HEATER SERVO
MOTOR AMPLIFIER
DIMMER SW
[COMB. SW]
CRUISE CONTROL
MIRROR SW
REAR WINDOW
DEFOGGER SW
POWER WINDOW
MASTER SW
POWER WINDOW
CONTROL RELAY
DOOR LOCK CONTROL
SW
REMOTE CONTROL
MIRROR SW
* The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.
E GLOSSARY OF TERMS AND SYMBOLS
BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.GROUND
The point at which wiring attaches to
the Body, thereby providing a return
path for an electrical circuit; without a
ground, current cannot flow.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.HEADLIGHTS
Current flow causes a headlight
filament to heat up and emit light. A
headlight may have either a single
(1) filament or a double (2) filament
1. SINGLE
FILAMENT
CIGARETTE LIGHTER
An electric resistance heating
element.2. DOUBLE
FILAMENT
CIRCUIT BREAKER
Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it.
Some units automatically reset when
cool, others must be manually reset.HORN
An electric device which sounds a
loud audible signal.
DIODE
A semiconductor which allows
current flow in only one direction.IGNITION COIL
Converts low±voltage DC current
into high±voltage ignition current for
firing the spark plugs.
DIODE, ZENERA diode which allows current flow in one
direction but blocks reverse flow only up
to a specific voltage. Above that potential,
it passes the excess voltage. This acts as
a simple voltage regulator.LIGHT
Current flow through a filament
causes the filament to heat up and
emit light.
PHOTODIODE
The photodiode is a semiconductor
which controls the current flow
according to the amount of light.LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes emit
light without producing the heat of a
comparable light.
DISTRIBUTOR, IIA
Channels high±voltage current from
the ignition coil to the individual
spark plugs.METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to move,
thereby providing a relative display
against a background calibration.
FUSEA thin metal strip which burns through
when too much current flows through it,
thereby stopping current flow and
protecting a circuit from damage.
FUSIBLE LINK
METER, DIGITAL
Current flow activates one or many
LED's, LCD's, or fluorescent
displays, which provide a relative or
digital display.
FUEL
FUSIBLE LINK
A heavy±gauge wire placed in high
amperage circuits which burns through on
overloads, thereby protecting the circuit.
The numbers indicate the crosssection
surface area of the wires.(for Medium Current Fuse)
(for High Current Fuse or
Fusible Link)MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion.
M
E
RELAY
Basically, an electrically operated
switch which may be normally
closed (1) or open (2).
Current flow through a small coil
creates a magnetic field which either
opens or closes an attached switch.
1. NORMALLY
CLOSED
2. NORMALLY
OPEN
SWITCH, MANUAL
Opens and closes
iitth b
SPEAKER
An electromechanical device which
creates sound waves from current
flow.
RELAY, DOUBLE THROW
A relay which passes current
through one set of contacts or the
other.
circuits, thereby
stopping (1) or
allowing (2) current
flow.1. NORMALLY
OPEN
2. NORMALLY
CLOSED
RESISTOR
An electrical component with a fixed
resistance, placed in a circuit to
reduce voltage to a specific value.SWITCH, DOUBLE THROW
A switch which continuously passes
current through one set of contacts
or the other.
RESISTOR, TAPPED
A resistor which supplies two or
more different non adjustable
resistance values.SWITCH, IGNITION
A key operated switch with several
positions which allows various
circuits, particularly the primary
ignition circuit, to become
operational.
RESISTOR, VARIABLE or RHEOSTAT
A controllable resistor with a variable
rate of resistance.
Also called a potentiometer or
rheostat.
SENSOR (Thermistor)
A resistor which varies its resistance
with temperature.SWITCH, WIPER PARK
Automatically returns wipers to the
stop position when the wiper switch
is turned off.
(Reed Switch Type)
SENSOR, SPEED
Uses magnetic impulses to open
and close a switch to create a signal
for activation of other components.TRANSISTOR
A solidstate device typically used as
an electronic relay; stops or passes
current depending on the voltage
applied at ºbaseº.
SHORT PIN
Used to provide an unbroken
connection within a junction block.WIRES
Wires are always drawn as
straight lines on wiring
diagrams.
Crossed wires (1) without a
black dot at the junction are
tj i d
(1) NOT
CONNECTED
SOLENOID
An electromagnetic coil which forms
a magnetic field when current flows,
to move a plunger, etc.
j
not joined;
crossed wires (2) with a
black dot or octagonal ( )
mark at the junction are
spliced (joined)
connections.
(2) SPLICED