2000 TOYOTA CAMRY ignition

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
156BE14
Warning Light for
Front Passenger
Land Cruiser 8
2) Front Passenger Seat Belt Buckle / Retractor Switch
The front passenger seat belt buckle / retractor switch is enclosed in the seat belt buckle / retractor of the
front passenger seat to detect whether or not the seat belt for the front passenger is being worn.
3) Seat Belt Warning Light for Front Passenger
The seat belt warning light for front passenger flashes to warn if the front passenger does not have the
seat belt buckled.
Operation
When an occupant is seated in the front passenger seat, the occupant detection sensor activates, thus enab-
ling the system to recognize that the occupant has seated. When the ignition switch is turned ON, a warning
light flashes if the front passenger is not wearing the seat belt. The warning light continues to flash until
the front passenger wears the seat belt.
If the front passenger seat is not occupied, the warning light remains extinct regardless of the condition of
the seat belt.

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.

NF
NEW FEATURES Ð 5S-FNE ENGINE13
FUEL SYSTEM
1. General
The compressed gas [maximum pressure approximately 250 kg/cm2 (3600 psi, 24.8 MPa) @215C (705F)]
from the CNG fuel tank located in the rear section of the vehicle is routed via a fuel filter to the engine
compartment. The pressure of the fuel is then reduced to 8 kg/cm
2 (114 psi, 785 kPa).
A pressure regulator and injectors designed exclusively for CNG application have been adopted.
A fuel pressure sensor and a fuel temperature sensor that are used for the correction of the fuel injection
volume are located on the delivery pipe.
The fuel tank, pressure regulator, and the delivery pipe are provided with shutoff valves that shut off
the fuel when the ignition switch is turned OFF.
In addition, these valves shut off the fuel when the engine stalls, the SRS airbag is deployed, or the
pressure in the main pipe becomes abnormally low.
A fuel temperature sensor for the fuel gauge is mounted on the tank valve assembly, and a fuel pressure
sensor is mounted immediately upstream of the pressure regulator.

Fuel System Diagram 
167CN12
Discharge
Valve
Fuel
Pressure
SensorFuel Temp.
SensorFuel
Pressure
RegulatorFuel Shutoff ValveFuel TankFuel Shutoff Valve
Relief Valve
Inlet Check
Valve
Fuel Temp.
Sensor
Coupler
Tank Valve Assembly
Vent Tube Manual
Shutoff
Valve Fuel
Filter
Fuel
Pressure
Sensor
Fuel Shutoff Valve Injectors
Delivery Pipe

NF
NEW FEATURES Ð 5S-FNE ENGINE15
Fuel Shutoff Valve for Fuel Tank
This valve uses an solenoid valve. The main pipe that supplies compressed gas to the engine is connected
to this valve, which opens when the ignition switch is turned ON. If the engine stalls, this valve automatical-
ly shuts off the fuel even if the ignition switch is turned ON. The valve reopens upon restarting the engine.
Also, this valve shuts off the fuel if the SRS airbag is deployed in a collision or if the pressure in the
main pipe becomes abnormally low.
Inlet Check Valve
Connected to a filler pipe that guides the fuel that fills through the coupler, the inlet check valve shuts
off by the force of a spring and by the pressure of the gas in the tank.
During filling, the pressure of the filling gas opens the inlet check valve.
Relief Valve
A vent tube is connected to this valve.
If the fuel tank is exposed to an abnormally high temperature, this valve opens (by melting) to discharge
the CNG at a predetermined temperature, thus preventing the fuel tank from bursting due to the increase
in gas pressure.
The discharged CNG is guided under the floor through a vent tube and is released outside of the vehicle.
4. Coupler
The coupler allows the fuel to be filled when it is connected with a fuel filling nozzle. The coupler has
a built-in check valve to prevent the CNG from flowing backward.
5. Manual Shutoff Valve
This valve is mounted below the vehicle floor.
When servicing the vehicle, this valve can be manu-
ally turned 90 degrees to shut off the main pipe.
167CN09

NEW FEATURES Ð 5S-FNE ENGINE 18
10. Fuel Temperatur and Pressure Sensor for Fuel Gage
A fuel temperature sensor that detects the temperature in the fuel tank is provided on the tank valve assembly.
A fuel pressure sensor that detects the pressure in the fuel main pipe is provided immediately upstream
of the fuel pressure regulator.
The pressure and the temperature of the fuel are detected by these sensors and are input into the ECM.
These values are then converted by the ECM into the equivalent pressure at 215C to actuate the fuel gauge.
IGNITION SYSTEM
Because the spark plugs are susceptible to rust when used with natural gas, corrosion-resistant spark plugs
have been adopted. These spark plugs are the iridium-tipped spark plugs that have their metallic portion
plated.

Recommended Spark Plug 
DENSO
SK20R11-G
Plug Gap1.0 ± 1.1 mm (0.0394 ± 0.043 in.)
167CN15
: Plating Area
Iridium Tip
Platinum Tip 0.7 mm

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

NEW FEATURES Ð 5S-FNE ENGINE
(Continued)
PIM
NE
G
THW
THA
VTA
AF
#10+
#20
#30
#40
IGT1,
IGT2
IGF
RSD
EGR
OX2
HTAF
HT2
MGC
FUEL W
PSW
ELS
NSW
F/PS
A/C SW
ECM
STA
SPD
R,2,L
STP
#40+ #30+ #20+ #10
FUEL
20
2. Construction
The configuration of the engine control system in the 5S-FNE engine is as shown in the following chart.
SENSORS
MANIFOLD ABSOLUTE
PRESSURE SENSOR
CRANKSHAFT POSITION
SENSOR
CAMSHAFT POSITION
SENSOR
ENGINE COOLANT TEMP.
SENSOR
INTAKE AIR TEMP. SENSOR
THROTTLE POSITION SENSOR
IGNITION SWITCH
COMBINATION METER
wVehicle Speed Signal
AIR FUEL RATIO SENSOR
(Bank 1, Sensor 1)
HEATED OXYGEN SENSOR
(Bank 1, Sensor 2)
POWER STEERING OIL
PRESSER SWITCH
TAILLIGHT & REAR WINDOW
DEFOGGER SYSTEM
PARK/NEUTRAL POSITION
SWITCH
STOP LIGHT SWITCH
AIR CONDITIONING SWITCH
AIRBAG SENSOR ASSEMBLY
wFuel Cut-Off Signal
ACTUATORS
SFI
No. 1 INJECTOR
No. 2 INJECTOR
No. 3 INJECTOR
No. 4 INJECTOR
ESA
IGNITERS and
IGNITION COILS
SPARK PLUGS
IAC
CONTROL VALVE
EGR
VSV
AIR FUEL RATIO SENSOR
HEATER CONTROL
AIR FUEL RATIO SENSOR
HEATER
OXYGEN SENSOR HEATER
CONTROL
HEATED OXYGEN SENSOR
HEATER
AIRE CONDITIONING
CUT-OFF CONTROL
MAGNET CLUTCH RERAY
FUEL GAGE
LOW FUEL LEVEL WARNING
LIGHT