2000 TOYOTA CAMRY stop start

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

3
CAMRY ± NEW FEATURES
172CM18
172CM19
ON
OFF1 sec 1 sec
1 sec 1 sec
ON
OFF1 sec 1 sec
2 sec 2 sec 2 sec53
Injector Control
1) General
Fuel clearing control and injector unsticking control have been added to the injector control.
2) Fuel Clearing Control
While the vehicle is being driven at speeds higher than 60 km / h (37.5 mph), and the ignition switch is
turned OFF after the ECM has detected a low temperature condition of less than 25C (77F) of intake
air temperature, the ECM closes the fuel shutoff valve for the delivery pipe. However, instead of immedi-
ately stopping the engine, the fuel clearing control allows the engine to stop on its own after the fuel in
the delivery pipe has been used up. If the engine is running even after 2 seconds or more have elapsed
after the ignition switch has been turned OFF, the EFI relay is turned OFF to stop the engine.
3) Injector Unsticking Control
When the ignition switch is turned ON after executing the fuel clearing control, the injector unsticking
control activates two cylinders at a time to unstick the valve that is frozen stuck onto the valve seat. At
low temperature conditions. At this time, the shutoff valve remains closed so that the injectors will not
inject fuel.
Gas Leak Judgment
If the ECM has detected a gas leak through the signals received from the pressure sensors, the ECM closes
the shutoff valves and flashes the low fuel level warning light.
These functions are canceled by resetting the ECM (by disconnecting the negative [-] terminal of the bat-
tery), which enables the engine to start.
(The ECM should be reset only after performing a gas leak check and making sure that the leak has been
eliminated.)
NOTE: The low fuel level warning light also flashes when the fuel level is extremely low. The flashing
patterns shown below differentiates a gas leak from a low fuel level.
Flashing Pattern
Gas Leak
Fuel Low Level

(q) Stop the engine.
(r) Check that the fuel pressure remains 147 kPa (1.5
kgf/cm
2, 21 psi) or more for 5 minutes after the
engine is turned off.
If pressure is not as specified, check the fuel pump,
pressure regulator and/or injector.
(s) After checking fuel pressure, disconnect the battery
negative (±) cable and carefully remove the SST to
prevent gasoline from splashing.
SST 09268±45012
(t) Connect the fuel inlet hose with 2 new gaskets and
the union bolt.
Torque: 29 N±m (300 kgf±cm. 22 ft±lbf)
(u) Reconnect the cable to the negative (±) terminal of
the battery.
(v) Check for fuel leakage.(o) Reconnect the vacuum sensing hose to the air intake
chamber.
(p) Measure the fuel pressure at idle.
Fuel pressure:
206 ± 255 kPa (2.1 ± 2.6 kgf/cm
, 31 ± 37 psi)
If pressure is not as specified, check the vacuum
sensing hose and fuel pressure regulator.(l) Start the engine.
(m) Disconnect the vacuum sensing hose from the air
intake chamber and plug the air intake chamber
outlet.
(n) Measure the fuel pressure at idle.
Fuel pressure:
265 ± 304 kPa (2.7 ± 3.1 kgf/cm
, 38 ± 44 psi) (k) Remove the SST.
SST 09483±18020
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±180

2. INSPECT THROTTLE POSITION SENSOR
(a) Apply vacuum to the throttle opener.
(b) Disconnect the sensor connector.
(c) Insert a thickness gauge between the throttle stop
screw and stop lever.
ON±VEHICLE INPSECTION
1. INSPECT THROTTLE BODY
(a) Check that the throttle linkage moves smoothly.
(b) Check the vacuum at each port.
wStart the engine.
wCheck the vacuum with your finger.
THROTTLE BODY
Other than idle
No vacuum
No vacuum No vacuum
No vacuum Port name
Vacuum Vacuum At idle
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±204

9=4 ±01
ELECTRIC COOLING FAN COMPONENTS
INSPECTION
1. INSPECT ENGINE COOLANT TEMPERATURE
SWITCH
(a) Using an ohmmeter, check that there is no continuity
between the terminals when the engine coolant tem±
perature is above 93
C (199
F).
(b) Using an ohmmeter, check that there is continuity
between the terminals when the engine coolant tem±
perature is below 83
C (181
F).
If continuity is not as specified, replace the switch. 2. DISCONNECT ENGINE COOLANT TEMPERATURE
SWITCH CONNECTOR
Check that the cooling fan rotates.
If not, check the cooling fan relay, cooling fan, engine
main relay and fuse, and check for a short circuit
between the cooling fan relay and engine coolant
temperature switch.
3. CONNECT ENGINE COOLANT TEMPERATURE
SWITCH CONNECTOR
ON±VEHICLE INSPECTION
Low Temperature (Below 83

C (181
F))
1. TURN IGNITION SWITCH ªONº
Check that the cooling fan stops.
If not, check the cooling fan relay and engine coolant
temperature switch, and check for a separated con±
nector or severed wire between the cooling fan relay
and engine coolant temperature switch.
High Temperature (Above 93
C (199
F))
4. START ENGINE
(a) Raise engine coolant temperature to above 93
C
(199
F).
(b) Check that the cooling fan rotates.
If not, replace the engine coolant temperature switch.
± 5S±FE ENGINECOOLING SYSTEMEG1±262

BASIC INSPECTION
When the normal code is displayed in the diagnostic trouble code check, troubleshooting should be
performed in the order for all possible circuits to be considered as the causes of the problems.
In many cases, by carrying out the basic engine check shown in the following flow chart, the location
causing the problem can be found quickly and efficiently. Therefore, use of this check is essential in en-
gine troubleshooting.
Remove air filter.
Visually check that the air filter is not excessively
damaged or oily.
If necessary, clean the air filter with compressed
air. First blow from inside thoroughly, then blow
off outside of the air filter.
Is battery positive voltage 11 V or more when engine is stopped?
Proceed to matrix chart of problem
symptoms on page EG1±327.
Is engine cranked ?
Does engine start
Charge or replace battery.
Check air filter.
Repair or replace. Go to step
Go to step
YESYES
YES
± 5S±FE ENGINEBASIC INSPECTIONEG1±310

*
: Only for California specification vehicles.
*: Except California specification vehicles with A/T.wStoplight switch
w Stoplight
w Park/neutral position switch wDefogger relay
wTaillight relay
Park/neutral position switchPark/neutral position switch
Park/neutral position switch
Malfunction indicator lampData link connector 1 and 2 Data link connector 1 and 2No.1 vehicle speed sensor
Throttle position sensor
Throttle position sensorEGR gas temp. sensor
Circuit opening relay Data link connector 1Data link connector 2
Cruise control ECUO/D main switch Terminal
No.Terminal
No.Connection
A/C amplifier
EFI main relay Sensor ground
Sensor ground
A/C amplifierEFI main relay
Knock sensorStarter relay Connection Symbol
Symbol
Battery
± 5S±FE ENGINETERMINALS OF ECMEG1±321

CIRCUIT DESCRIPTION
The ECM determines the ignition timing, turns on Tr, at a predetermined angle ('*CA) before the
desired ignition timing and outputs an ignition signal (IGT) ª1º to the igniter.
Since the width of the IGT signal is constant, the dwell angle control circuit in the igniter determines
the time the control circuit starts primary current flow to the ignition coil based on the engine rpm and
ignition timing one revolution ago, that is, the time the Tr
2 turns on.
When it reaches the ignition timing, the ECM turns Tr, off and outputs the IGT signal ªOº.
This turns Tr2 off, interrupting the primary current flow and generating a high voltage in the secondary
coil which causes the spark plug to spark. Also, by the counter electromotive force generated when
the primary current is interrupted, the igniter sends an ignition confirmation signal (IGF) to the ECM.
The ECM stops fuel injection as a fail safe function when the lG F signal is not input to the ECM.
wOpen or short in IG F or IGT circuit from
igniter to ECM.
wIgniter
wECM No IGF signal to ECM for 4 (8*2) consecutive
IGT signals. Diagnostic Trouble Code Detecting Condition
WIRING DIAGRAM
Trouble Area
DTC 14 Ignition Signal Circuit
DTC No.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±344