2000 TOYOTA CAMRY ESP

3
CAMRY ± NEW FEATURES
172CM13
Discharge
ValveFuel Pressure Sensor
Fuel Temp. SensorDelivery Pipe
CNG
Fuel Shutoff
Valve
Injector
167CN23
Rubber Sheet47
Delivery Pipe
A delivery pipe with a wide passage that enables a large volume of gas to flow responsively has been
adopted to minimize the pressure loss.
A fuel pressure sensor and a fuel temperature sensor that help correct the fuel injection volume are
mounted on the delivery pipe.
Similar to the fuel shutoff valves for the fuel tank and the fuel pressure regulator, a fuel shutoff valve is
provided on the fuel inlet side of the delivery pipe to shut off the supply of fuel when the engine is stopped
or during abnormal conditions.
To discharge the fuel out of the delivery pipe during service, a discharge valve is provided.
Injector
For the injection of fuel in the gaseous state, injectors that allow the flow of a large volume of fuel and pro-
vide improved sealing performance have been adopted.

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

ELECTRONIC CONTROL SYSTEM
The CAMRY 5S±FE engine is equipped with a TOYOTA Computer Controlled System (TCCS)
which centrally controls the MFI/SFI, ESA, IAC diagnosis systems etc. by means of an Engine
Control Module (ECM±formerly MFI/SFI computer) employing a microcomputer.
The ECM controls the following functions:
1. Multiport Fuel Injection (MFI)/Sequential Multiport Fuel Injection (SFI)
The ECM receives signals from various sensors indicating changing engine operation conditions
such as:
Intake manifold pressure
Intake air temperature
Engine coolant temperature
Engine speed
Throttle valve opening angle
Exhaust oxygen content etc.
The signals are utilized by the ECM to determine the injection duration necessary for an optimum
air±fuel ratio.
2. Electronic Spark Advance (ESA)
The ECM is programmed with data for optimum ignition timing under all operating conditions.
Using data provided by sensors which monitor various engine functions (RPM, engine coolant
temperature, etc.), the microcomputer (ECM) triggers the spark at precisely the right instant.
3. Idle Air Control (IAC)
The ECM is programmed with target idling speed values to respond to different engine conditions
(engine coolant temperature, air conditioning ON/OFF, etc.). Sensors transmit signals to the ECM
which controls the flow of air through the bypass of the throttle valve and adjusts idle speed to
the target value.
4. Diagnosis
The ECM detects any malfunctions and abnormalities in the sensor network and lights a
malfunction indicator lamp in the combination meter. At the same time, trouble is identified and
a diagnostic trouble code is recorded by the EC
5. The diagnostic trouble code can be read by the
number of blinks of the malfunction indicator lamp when terminals TE1 and E1 are connected.
The diagnostic trouble codes are referred to in later page. (See page EG1±300)
Fail±Safe Function
In the event of the sensor malfunction, a back±up circuit will take over to provide minimal
driveability, and the malfunction indicator lamp will illuminate. The MFI (Multiport Fuel Injection)/SFI (Sequential Multiport Fuel Injection) system is composed
of 3 basic sub±systems: Fuel, Air Induction and Electronic Control Systems.
FUEL SYSTEM
Fuel is supplied under constant pressure to the MFI/SFI injectors by an electric fuel pump. The
injectors inject a metered quantity of fuel into the intake port in accordance with signals from the
ECM (Engine Control Module).
AIR INDUCTION SYSTEM
The air induction system provides sufficient air for engine operation.
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±166

PRECAUTION
1. Before working on the fuel system, disconnect the
negative (±) terminal cable from the battery.
HINT: Any diagnostic trouble code retained by the
computer will be erased when the battery terminal is
removed.
Therefore, if necessary, read the diagnosis before
removing the terminal.
CAUTION: Work must be started after 90 seconds from
the time the ignition switch is turned to the 'LOCK'
position and the negative (±) terminal cable is discon±
nected from the battery.
2. Do not smoke or work near an open flame when
working on the fuel system.
3. Keep gasoline away from rubber or leather parts.
3. IN EVENT OF ENGINE MISFIRE, FOLLOWING
PRECAUTIONS SHOULD BE TAKEN
(a) Check proper connection of battery terminals, etc.
(b) Handle high±tension cords carefully.
(c) After repair work, check that the ignition coil termi±
nals and all other ignition system lines are reconne±
cted securely.
(d) When cleaning the engine compartment, be especially
careful to protect the electrical system from water.
4. PRECAUTIONS WHEN HANDLING OXYGEN
SENSOR
(a) Do not allow oxygen sensor to drop or hit against an
object.
(b) Do not allow the sensor to come into contact with
water.
MAINTENANCE PRECAUTIONS
1. CHECK CORRECT ENGINE TUNE±UP
(See page EG1±8)
2. PRECAUTION WHEN CONNECTING GAUGE
(a) Use battery as the power source for the timing light,
tachometer, etc.
(b) Connect the tester probe of a tachometer to the termi±
nal IGE) of the data link connector 1.
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±172

ELECTRONIC CONTROL SYSTEM
1. Before removing MFI/SFI wiring connectors, termi±
nals, etc., first disconnect the power by either turning
the ignition switch OFF or disconnecting the battery
terminals.
HINT: Always check the diagnostic trouble code
before disconnecting the negative (±) terminal cable
from the battery.
2. When installing the battery, be especially careful not
to incorrectly connect the positive (+) and negative
(±) cables.
3. Do not permit parts to receive a severe impact during
removal or installation. Handle all MFI/SFI parts care±
fully, especially the ECM.
4. Do not be careless during troubleshooting as there are
numerous transistor circuits and even slight terminal
contact can further troubles.
5. Do not open the ECM cover.
6. When inspecting during rainy weather, take care to
prevent entry of water. Also, when washing the
engine compartment, prevent water from getting on
the MFI/SFI parts and wiring connectors.
7. Parts should be replaced as an assembly.
AIR INDUCTION SYSTEM
1. Separation of the engine oil dipstick, oil filler cap, PCV
hose, etc. may cause the engine to run out of tune.
2. Disconnection, looseness or cracks in the parts of the
air induction system between the throttle body and
cylinder head will allow air suction and cause the
engine to run out of tune.
IF VEHICLE IS EQUIPPED WITH MOBILE
RADIO SYSTEM (HAM, CB, ETC.)
If the vehicle is equipped with a mobile communica±
tion system, refer to the precaution in the IN section.
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±173

37 ENGINEÐ5S±FE ENGINE
 ENGINE CONTROL SYSTEM
1. General
The engine control system of the new 5S±FE engine is basically the same in construction and operation as that of the
previous 5S±FE engine, except fo rthe changed listed bleow.
The exhaust emissions has been reduced through the adoption of the sequential multiport fuel injection system for
engine starting and the air±fuel ratio sensor*
2
The function of an air conditioning amplifier has been internally added to the ECM.
The engine control system of the new 5S±FE engine and previous 5S±FE engine and previous 5S±FE engine are
compared below.
System
OutlineNewPrevious
SFI
(SequentialA D±type SFI system is used, which indirectly detects
intake air volume by manifold absolute pressure.(q
Multiport Fuel
Injection)The fuel injection system is a sequential multiport fuel
injection system.
ESA
(Electronic SparkIgnition Timing is determined by the ECM based on
signals from various sensors. The ECM corrects ignition
timing in response to engine knocking.

(Electronic Spark
Advance)Torque control correction during gear shifting has been
used to minimize the shift shock.*1*1
IACA rotary solenoid type IAC valve controls the fast idle(Idle Air Control)
A rotary solenoid type IAC valve controls the fast idle
and idle speeds.
Fuel Pump
ControlFuel pump operation is controlled by signal from the
ECM.
Oxygen Sensor
(Air Fuel Ratio
Sensor*
2)
Heater Control
Maintains the temperature of the oxygen sensor (or air
fuel ratio sensor*2) at an approppiate level to increase
accuracy of detection of the oxygen concentration in the
exhaust gas.Ð
EGR Cut±Off
ControlCuts off EGR according to the engine condition to
maintain drivability of the vehicle and durability of
EGR components.

Evaporative
Emission ControlThe ECM controls the purge flow of evaporative emis-
sions (HC) in the charcoal canister in accordance with
engine conditions.
*1*1
Air Conditioning
Cut±Off ControlBy turning the air conditioning compressor ON or
OFF in accordance with the engine condition,
drivability is maintained
*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 control system.*1*1
Fail SafeWhen 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 Models., *2: Only for California Specification Models,
*
3: The air conditioning magnet scutch controled by the ECM.

48ENGINEÐ1MZ±FE ENGINE

ENGINE CONTROL SYSTEM
1. General
The engine control system of the new 1MZ±FE engine is basically the same in construction and operation as that of
the previous 1MZ±FE engine. However, the fuel pressure control has been discontinued and the EGR control system
has been changed.
The engine control system of the new 1MZ±FE engine and previous 1MZ±FE engine are compared below.
System
OutlineNewPrevious
SFI
(SequentialA L±type SFI system directly detects intake air mass with
a hot wire type mass air flow meter.(q
Multiport Fuel
Injection)The fuel injection system is a sequential multiport fuel
injection system.
ESA
Ignition Timing is determined by the ECM based on
signals from various sensors. The ECM corrects ignition
timing in response to engine knocking.

(Electronic Spark2 knock sensors are used to improve knock detection.(p
Advance)In vehicles equipped with automatic transaxle, torque
control correction during gear shifting has been used to
minimize the shift shock.

IACA rotary solenoid type IAC valve controls the fast idle(Idle Air Control)
A rotary solenoid type IAC valve controls the fast idle
and idle speeds.
ACIS
(Acoustic Control
The intake air passages are switched according to the en-
gine speed and throttle valve angle to increase perfor(Acoustic Control
Induction System)
gine speed and throttle valve angle to increase perfor-
mance in all speed ranges.
Fuel Pressure
ControlIn hot engine conditions, the fuel pressure is increased to
improve restartability.
Oxygen Sensor
Heater ControlMaintains the temperature of the oxygen sensor at an
approppiate level to increase accuracy of detection of
the oxygen concentration in the exhaust gas.

EGR Cut±Off
ControlCuts off EGR according to the engine condition to
maintain drivability of the vehicle and durability of
EGR components.
Ð
EGR Control
Uses the duty control type VSV and EGR valve position
sensor, controlling the EGR volumne in accordance with
engine conditions.
Ð
Evaporative
Emission ControlThe ECM controls the purge flow of evaporative emis-
sions (HC) in the charcoal canister in accordance with
engine conditions.

Diagnosis
When the ECM detects a malfunction, the ECM diagnoses
and memorizes the failed section.
DiagnosisThe diagnosis system includes a function that detects a
malfunction in the evaporative control system.Ð
Fail SafeWhen the ECM detects a malfunction, the ECM stops
or controls the engine according to the data already stored
in memory


116BODY ELECTRICALÐACCESSORIES
 CRUISE CONTROL SYSTEM
1. General
Once the system is set to a desired vehicle speed, the engine throttle position is adjusted automatically to maintain
the vehicle speed at that speed without depressing the accelerator pedal.
The basic sonstruction and operation of this system are the same as the previous model. However, on the new model,
the control method for the manual and auto cancel functions have been changed. Also, a new motor type actuator
that is both lightweight and simple in construction has been adopted.
2. Construction and Operation
Actuator
The new Camry has adopted a new motor type actuator. The new motor type actuator consists of a motor, control link
and limit swit h, etc. as shown belwo.
The potentiometer hat measured the opening angle of the control link and transmitted the signals to the cruise control
ECU has been discontinued in the new actuator. The new actuator is equipped it with a compact motor. As a result,
the new actuator is made both lightweight and simple in construction.
Without the potentiometer, the new actuator contnuously regulates the opening angle of the control link.
This is made possible by the ECU, which compares the curent vehiclespeed input with the desired vehicle speed that
is stored in memory, and the result of that comparison is transmitted to the actuator.
Cruise Control ECU
1) Manual Cancel Fucntion
The manual cancel function has been changed as follows:
New
Previous
Transaxle shifted to positions other than ªDº.Transaxle shifted to ªNº position.
ÐPull up the parking brake lever.