2000 TOYOTA CAMRY air fuel sensor

1
GENERAL 2000 FEATURES
170EG08
VSV
(for Canister
Closed Valve)VSV
(for
EVAP)
Fuel Tank
Purge Line
Fresh Air LineVapor Pressure
SensorVSV
(for Pressure Switching Valve)
Chacoal Canister
Fresh Air Valve
Drain 2
ENGINE
EVAPORATIVE EMISSION CONTROL SYSTEM
The method for detecting evaporative emission leaks has been changed from the previous internal pressure
monitor type to the vacuum type. The vacuum type forcefully introduces the purge vacuum into the entire
system and a leak is detected by monitoring the transitions in pressure. The changes associated with this sys-
tem are as follows:

A VSV for canister closed valve has been added to the fresh air introduction line.

The 3-way VSV for vapor pressure sensor has been discontinued, and a VSV for pressure switching valve
has been added.

The sensing position of the vapor pressure sensor has been changed from the charcoal canister to the fuel
tank in order to enhance the precision of the vapor pressure sensor.

The fresh air valve characteristics of the charcoal canister have been changed.

Diagnostic trouble codes (DTCs) have been added. For details on the DTCs, refer to the each Repair Manu-
al.

3
CAMRY ± OUTLINE OF NEW FEATURES27
8. Brakes
The specifications of the front and rear brakes have been changed.
9. Suspension
The front and rear springs, stabilizers, and shock absorbers have been modified to realize excellent stability,
controllability, and riding comfort.
10. Steering
A check valve has been added to the power steering gear box to help reduce kickback.
The rack stroke of the 5S-FE engine model has been changed to 145mm (5.71 in.), which is the same as
in the 1MZ-FE engine.
11. Body
Hood support dampers are used.
Two utility hooks added in the luggage room for the gasoline engine model.
To install the fuel tank in the front area of the luggage compartment, the upper back panel has been cut
out for the 5S-FNE engine model.
A performance rod that joins the tops of the right and left rear suspension strut towers has been adopted
for the 5S-FNE engine model.
The shape of the rear floor pan has been changed to prevent the luggage compartment capacity from being
reduced as a result of the installation of the fuel tank in the luggage compartment for the 5S-FNE engine
model.
12. Seat
The seat cover of the LE grade model has been changed.
Optional driver power seat added for the LE grade model.
A fixed type seat back is used for the rear seat for the 5S-FNE engine model.
13. Seat Belt
2-point NR (Non-Retractor) seat belt is used for the rear center seat for the 5S-FNE engine model.
14. Wireless Door Lock Control
Audio answer back is adopted.
15. Lighting
Along with the adoption of the 4-beam headlights, the electrical circuit of the daytime running light system
has been changed.
16. Air Conditioning
The air inlet mode selector of heater control panel has been changed from the lever type to the push button
type on the CE and LE grade model.
When the air outlet mode is set to the DEF or FOOT / DEF mode, the air inlet mode also changes to the
FRESH mode, has been also added on the CE and LE grade model.
A fully automatic controlled type air conditioning is used on the XLE grade model.
A defroster-linked air conditioning start up control has been continuing to use since the previous models
with air conditioning.
17. SRS Airbag
The inflator of the SRS airbag for the driver has been made more compact and lightweight.
A signal that causes the supply of fuel to be cut off during a frontal collision is output by the airbag sensor
assembly to the ECM for the 5S-FNE engine model.

CAMRY ± NEW FEATURES36
5S-FNE ENGINE
1. Description
The 5S-FNE engine is a new engine that uses CNG (Compressed Natural Gas) as fuel, which has been devel-
oped based on the 5S-FE gasoline engine.
The main component of natural gas is methane (CH
4), which has fewer carbous (C) than gasoline (mean mo-
lecular formula: C
7.5H13.4). Therefore, the amount of CO2 discharged by this engine is approximately 70%
that of the gasoline engine. Furthermore, this engine achieves low-emission operation by precisely controlled
air-fuel ratio and using special catalysts for the CNG application.
However, because the fuel is in the gaseous form, its volumetric efficiency is low, causing lower power output
if this fuel is used in the base engine.
Therefore, the 5S-FNE engine has adopted the following features: a high compression ratio, the intake valves
with early closed timing, the intake and exhaust valves with increased lift, a low back pressure muffler made
possible by the 2-way exhaust system, injectors for gaseous fuel, and a catalytic converter designed exclu-
sively for CNG application. At the same time, precision air-fuel ratio control is effected through the use of
the air-fuel ratio sensor* and the heater oxygen sensor, thus achieving the level of performance that is equiva-
lent to the base engine. Moreover, this engine realizes extremely low emissions and restoring engine torque.
*: Already adopted on the California specification 5S-FE engine.

Specifications 
Item5S-FNE Engine5S-FE Engine
No. of Cyls. & Arrangement4-Cylinder, In-Line
Valve Mechanism16-Valve DOHC,
Belt & Gear Drive
Combustion CamberPentroof Type
ManifoldsCross-Flow
Fuel SystemSFI
Displacement cm3 (cu.in.)2164 (312.0)
Bore x Stroke mm (in.)87.0 x 91.0 (3.43 x 3.58)
Compression Ratio11.0 : 19.5 : 1
Max. Output [SAE-NET]88 kW @ 5200 rpm
(118 HP @ 5200 rpm)
101 kW @ 5200 rpm
(136 HP @ 5200 rpm)
97 kW @ 5200 rpm*
(133 HP @ 5200 rpm)*
Max. Torque [SAE-NET]178 N.m @ 2400 rpm
(131 ft-lbf @ 2400 rpm)
203 N.m @ 4400 rpm
(150 ft-lbf @ 4400 rpm)
201 N
.m @ 4400 rpm*
(148 ft-lbf @ 4400 rpm)*
IntakeOpen3 BTDC
Valve
IntakeClose38 ABDC43 ABDCValve
Timing
ExhaustOpen45 BBDCExhaustClose3 AT D C
Fuel Octane Number RON13091
Oil GradeAPI SJ EC or ILSAC
*: California Specification Models

CAMRY ± NEW FEATURES 38
2. Features of 5S-FNE Engine
Features of the 5S-FNE engine are listed below.
Item
Features
Performance
High compression ratio is used.
High lift camshaft is used.
Low back pressure muffler is used.
Fuel Economy
High compression ratio is used.
Valve spring load has been reduced.
Low-friction. TiN (titanium nitride) coated valve lifters has been adopted.
Low Emission
A fuel injection system containing gas injectors has been adopted.
Because the fuel is in the gaseous state, it does not come in contact with
the wall surface, making optimal air-fuel ratio control possible
immediately after the engine has been started.
Precision air-fuel ratio feedback control that uses an air-fuel ratio sensor
and a heated oxygen sensor has been adopted.
Two catalytic converters designed exclusively for the natural gas engine
have been adopted: the WU-TWC (Warm Up Three-Way Catalytic
Converter) and the TWC (Three-Way Catalytic Converter).
Other Features
Highly rigid pistons have been adopted to accommodate the high
compression ratio.
A CNG (Compressed Natural Gas) pressure regulator that precisely
regulates the CNG has been adopted.
A large-bore delivery pipe and fuel hose with minimal internal conduit
resistance have been adopted.
The electro magnetic fuel shutoff valve is added on the delivery pipe.
A fuel pressure sensor that corrects the fuel injection volume and a fuel
temperature sensor have been provided on the delivery pipe.
The starting performance of the engine at low temperatures has been
ensured by increasing the volume of the airflow of the IAC (Idle Air
Control).
Materials that excel in wear resistance have been adopted on the valves
and valve seats for both the intake and exhaust.
Rust-resistant spark plugs have been adopted.
Aluminum lining and carbon fiber have been adopted in the fuel tank.
For the fuel gauge, a fuel tank fuel temperature sensor and a fuel pipe fuel
pressure sensor have been adopted.

3
CAMRY ± NEW FEATURES
172CM14
Fuel
Pressure
SensorFuel Temp.
SensorFuel
Pressure
RegulatorFuel Shutoff ValveFuel Tank
Fuel Shutoff ValveRelief Valve
Inlet Check
Valve
Fuel Temp.
Sensor
Coupler
Tank Valve Assembly
Vent Tube Manual
Shutoff
Valve Oil
Separator
Fuel Shutoff Valve Injectors
Delivery Pipe Discharge
ValveFuel
Pressure
SensorFuel
Filter43
6. Fuel System
General
The compressed gas [maximum pressure approximately 250 kg / cm
2 (3600 psi, 24.8 MPa) @ 21C
(70F)] 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 pres-
sure 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 

3
CAMRY ± NEW FEATURES49
8. Engine Control System
General
An engine control system based on the 5S-FE engine has been adopted. The knock sensor has been discon-
tinued 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
Se
quential
A D-type SFI system is used, which indirectly detects
intake air volume by manifold absolute pressure sensor.Sequential
Multiport Fuel
InjectionThe fuel injection system is a sequential multiport fuel
injection system.
Ignition timing is determined by the ECM based on
signals from various sensors.
ESA
Electronic Spark
AdvanceThe ECM corrects the ignition timing in response to
engine knocking in accordance with the signals
received from the knock sensor.
Ð
dva ce
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
supply of fuel when the ignition switch is turned OFF or
during abnormal conditions (such as engine stalling,
SRS airbag deployed, etc.).
Ð
Injector ControlPrevents the frozen stuck of the injector to ensure the
startability of the engine at low temperature.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
accuracy of detection of the oxygen concentration in the
exhaust 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
emissions (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
Diagnosis
When the ECM detects a malfunction, the ECM
diagnoses and memorized the failed section.
DiagnosisThe diagnosis system includes a function that detects a
malfunction in the evaporative emission control system.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

CAMRY ± NEW FEATURES
No.4 INJECTOR
SPARK PLUGSIGNITERS and
IGNITION COILS
No.2 INJECTOR
No.1 INJECTOR
No.3 INJECTOR
SENSORS ACTUATORS
MANIFOLD ABSOLUTE
PRESSURE SENSORSFI PIM#10+
CRANKSHAFT POSITION
SENSORNE
CAMSHAFT POSITION
SENSORG
ENGINE COOLANT TEMP.
SENSORTHW
INTAKE AIR TEMP. SENSORTHA
THROTTLE POSITION SENSORVTA
COMBINATION METER
SPD
Vehicle Speed Signal
AIR FUEL RATIO SENSOR
(Bank 1, Sensor 1)AF
HEATED OXYGEN SENSOR
(Bank 1, Sensor 2)OX2
POWER STEERING OIL
PRESSER SWITCHPSW
TAILLIGHT & REAR WINDOW
DEFOGGER SYSTEMELS
IGNITION SWITCHSTA
PARK / NEUTRAL POSITION
SWITCHNSW
STOP LIGHT SWITCHSTP
AIRBAG SENSOR ASSEMBLY
F/PS
Fuel Cut-Off Signal
#10
#20+
#20
#30+
#30
#40+
#40
ESA
IGT1,
IGT2
IGF
CONTROL VALVEIACRSD
VSV EGREGR
AIR FUEL RATIO SENSOR
HEATER AIR FUEL RATIO SENSOR
HEATER CONTROLHTAF
HEATED OXYGEN SENSOR
HEATER OXYGEN SENSOR HEATER
CONTROLHT2
MAGNET CLUTCH RERAYAIRE CONDITIONING
CUT-OFF CONTROLMGC
FUEL GAGE
LOW FUEL LEVEL WARNING
LIGHT
ECM
AIR CONDITIONING SWITCHA/C SW
R, 2, L
FUEL
FUEL W
50
Construction
The configuration of the engine control system in the 5S-FNE engine is as shown in the following chart.
(Continued)

CAMRY ± NEW FEATURES
167CN11
Intake Air
Temp. SensorSpeedometerFuel Gage & Warning
MIL
DLC3
Airbag Sensor Assembly
ECM
VSV
(for EGR)
EGR Vacuum
ModulatorIAC Valve
Throttle
Position
Sensor
Fuel Temp.
Sensor
Fuel Shutoff
ValveFuel
Pressure
Regulator
Oil
SeparatorFuel
Shutoff
Valve
Fuel
Pressure
Sensor
EGR Valve
Crankshaft Position
Sensor Manifold
Absolute
Pressure
SensorFuel Pressure
Sensor
Engine Coolant
Temp. Sensor
Camshaft
Position
Sensor
Air Fuel
Ratio Sensor
WU-TWC
Heated Oxygen Sensor
TWCManual Fuel
Shutoff
ValveFuel Filter
Fuel TankFuel Temp. Sensor
Fuel Shutoff Valve
Coupler 52
Engine Control System Diagram