2000 TOYOTA CAMRY Knock sensor

wSpread the time on the horizontal axis, and
confirm that period of the wave is 132
sec.
(Normal mode vibration frequency of knock
sensor: 7.6 KHz).
HINT: If normal mode vibration frequency is not 7.6
KHz, the sensor is malfunctioning.wWith the engine racing (4,000 rpm) measure
waveform between terminal KN K of engine
control module and body ground.
HINT: The correct waveform appears as shown in the
illustration on the left.
INSPECTION USING OSCILLOSCOPE Reference
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±389

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.

42ENGINEÐ5S±FE ENGINE
5. Main Components of Engine Control System
The following table compares the main components of the new 5S±FE engine, and previous 5S±FE engine.
Model
NewPreviousComponentNewPrevious
Manifold Absolute Pressure SensorSemiconductoru
Throttle Position SensorLinear Typeu
Crankshaft Position SensorPick±Up Coil Type, 1u
Camshaft Position SensorPick±Up Coil Type, 1Ð
DistributorCamshaft PositionPick Up Coil Type 1DistributorSensorÐPick±Up Coil Type, 1
Knock SensorBuilt±In Piezoelectric
Element Type 1u
Oxygen Sensor
Heated Oxygen Sensor
(Bank 1, Sensor 1)*
1
(Bank 1, Sensor 2)
Air Fuel Ratio Sensor*
2
Oxygen Sensor
(Bank 1, Sensor 1)
(Bank 1, Sensor 2)
Injector2±Hole Typeu
IAC ValveRotary Solenoid Typeu
*1: Except for California Specification Models.
*
2: Only for California Specification Models.
Camshaft Position Sensor
The camshaft position sensor is mounted onto the
cylinder head. Using the protusion that is provided
on the timing pulley, the sensor generates 1 signal
for every revolution. This signal is then sent to the
ECM as a cranskshaft angle system.

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


CAMRY ± NEW FEATURES
No.2 INJECTOR
SENSORS ACTUATORS
VG
RSO IGF NE
ECM
IGTI

IGT3
#10
G22
THW
THA
VTA1
STA
SPD
AFR
AFL
OXS
EGLS
THG
KNKR
CF
NSW
A/C
ACIS
FC
ACT
MAFR
HAFL
HREL
#20
#30
#40
#50
#60
MASS AIR FLOW METER
R, 2, L KNKLIGSW
RSC
CRANKSHAFT POSITION SENSOR
Engine Speed Signal
Crankshaft Angle Signal
CAMSHAFT POSITION SENSOR
Crankshaft Angle Signal
ENGINE COOLANT TEMP.
SENSOR
INTAKE AIR TEMP. SENSOR
THROTTLE POSITION SENSOR
Throttle Position Signal
IGNITION SWITCH
Starting Signal
Ignition Signal
VEHICLE SPEED SENSOR
COMBINATION METER
AIR-FUEL RATIO SENSOR
(Bank 1, Sensor 1)
AIR-FUEL RATIO SENSOR
(Bank 2, Sensor 1)
HEATED OXYGEN SENSOR
(Bank 1, Sensor 2)
EGR VALVE POSITION SENSOR
EGR GAS TEMP. SENSOR
KNOCK SENSORS
PARK / NEUTRAL POSITION
SWITCH
Neutral Start Signal
AIR CONDITIONING AMPLIFIER
A / C Switch Signal
COOLING FAN RELAYNo.1 INJECTOR
No.3 INJECTOR
No.4 INJECTOR
No.5 INJECTOR
No.6 INJECTOR
ESA
IGNITER
IGNITION COILS
SPARK PLUGS
IAC
CONTROL VALVE
ACIS
VSV
FUEL PUMP CONTROL
CIRCUIT OPENING RELAY
AIR CONDITIONING CONTROL
AIR CONDITIONING
AMPLIFIER
AIR FUEL RATIO SENSOR
HEATER CONTROL
AIR FUEL RATIO SENSOR
HEATER RELAY
AIR FUEL RATIO SENSOR
HEATER (Bank 1, Sensor 1)
AIR FUEL RATIO SENSOR
HEATER (Bank 1, Sensor 2)SFI
(Continued)
KNOCK SENSORS
11
Construction
1) California Specification Automatic Transaxle Model
The configuration of the engine control system in the 1MZ-FE engine of the '98 Camry is as shown in
the following chart. Shaded portions
differ from the 1MZ-FE engine of the '97 Camry.

CAMRY ± NEW FEATURES
150EG01
Circuit Opening RelayIgnition
SwitchEFI
Main
Relay
DLC1 Pressure
RegulatorVehicle Speed
SensorPark / Neutral Position Switch*
Fuel Pump
BatteryMIL
Air
Conditioning
Amplifier
DLC3
Stop Light Switch
Electrical Load Switch
Air-Fuel Ratio Sensor Heater Relay
ECM Fuel
Filter
Pulsation
DamperVSV
(for EVAP)Vapor
Pressure
Sensor
VSV
for Vapor
Pressure
Sensor
Charcoal CanisterVCV
Intake Air Temp.
SensorIAC Valve
VSV (for EGR)
Mass Air Flow
Meter
Air-Fuel Ratio Sensor
(Bank 1, Sensor 1)Throttle
Position
Sensor
Actuator
DIS
Injector
VSV (for ACIS)
EGR
Valve
Position
Sensor
EGR
Valve EGR Gas
Temp. Sensor Camshaft
Position
Sensor
Engine Coolant
Temp. SensorWU-TWC
WU-TWC
Crankshaft
Position SensorKnock Sensors
Air-Fuel Ratio Sensor
(Bank 2, Sensor 1)Heated Oxygen Sensor
(Bank 1, Sensor 2)
13
Engine Control System Diagram
1) California Specification Automatic Transaxle Model
*: Only for the Automatic Transaxle Models

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

G
Position of Parts in Engine Compartment
[1MZ±FE]
I 1 Idle Air Control Valve
I 2 Igniter
I 5 Ignition Coil No.1
I 6 Ignition Coil No.2
I 7 Ignition Coil No.3
I 8 Injector No.1
I 9 Injector No.2
I 10 Injector No.3
I 11 Injector No.4
I 12 Injector No.5
I 13 Injector No.6
K 1 Knock Sensor 1
K 2 Knock Sensor 2
M 2 Mass Air Flow Meter
N 1 Noise Filter (Ignition)
O 1 Oil Pressure SW
P 1 Park/Neutral Position SW,A/T Indicator Light SW and
Back±Up Light SW
P 2 Power Steering Oil Pressure SWR 1 Radiator Fan Motor
S 1 Starter
S 2 Starter
T 1 Theft Deterrent Horn
T 2 Throttle Position Sensor
V 2 Vehicle Speed Sensor (Combination Meter)
V 3 Vehicle Speed Sensor
(Electronically Controlled Transmission)
V 4 VSV (EGR)
V 5 VSV (EVAP)
V 6 VSV (Intake Air Control)
W 1 Washer Level Warning SW
W 2 Washer Motor
W 3 Water Temp. Sender
W 4 Water Temp. SW No.1
W 5 Water Temp. SW No.2