2001 TOYOTA PRIUS O2 sensor

ENGINE ± 1NZ-FXE ENGINE
182EG19
Air CleanerIntake Air Chamber
VSV (for EVAP)
ECM
VSV (for Purge Flow
Switching Valve)
Charcoal Canister
Vapor Pressure
Sensor
VSV (for Canister Closed Valve) Fuel Inlet Pipe Fuel: Vapor
: Fuel59
4. ORVR System
The ORVR (On-Board Refueling Vapor Recovery) is a system that uses a charcoal canister, which is provided
onboard, to recover the fuel vapor that is generated during refueling. This reduces the discharge of fuel vapor
into the atmosphere.
5. Fuel Tank
General
To reduce the amount of fuel vapor generated when the vehicle is parked, during refueling, or while driv-
ing, a vapor reducing fuel tank system has been adopted.
This system provides a vapor reducing fuel tank that expands or contracts in accordance with the volume
of the fuel in the fuel storage area in the fuel tank. By thus reducing the space in which fuel can evaporate,
the generation of fuel vapor is minimized.
Along with the provision of the vapor reducing fuel tank whose size fluctuates in the fuel tank, the fuel
gauge and the fuel pump have been provided in the sub tank. For this reason, a direct-acting fuel gauge
has been adopted.
NOTE:At low ambient temperatures, the capacity of the vapor reducing fuel tank is reduced as it is
made of resin (When the outside temperature is at ±10C (14F) the size of the tank will be re-
duced by approximate 5 liters).

ENGINE ± 1NZ-FXE ENGINE
165EG25
Camshaft
Position
Sensor
Crankshaft
Position
Sensor
Various
SensorsG2
NEECM
IGT1
IGT2
IGT3
IGT4
IGF+BIgnition Coil
(with Igniter)
No.1
Cylinder
No.2
Cylinder
No.3
Cylinder
No.4
Cylinder61

IGNITION SYSTEM
1. General
A DIS (Direct Ignition System) has been adopted. The DIS improves the ignition timing accuracy, reduces
high-voltage loss, and enhances the overall reliability of the ignition system by eliminating the distributor.
The DIS in 1NZ-FXE engine is an independent ignition system which has one ignition coil (with igniter) for
each cylinder.
2. Ignition Coil
The DIS provides 4 ignition coils, one for each cylinder. The spark plug caps, which provide contact to the
spark plugs, are integrated with an ignition coil. Also, an igniter is enclosed to simplify the system.
3. Spark Plug
Iridium-tipped spark plugs have been adopted to realize a 60,000-mile (100,000 km) maintenance-free op-
eration. Their center electrode is made of iridium, which excels in wear resistance. As a result, the center
electrode is made with a smaller diameter and improved the ignition performance.

CHARGING AND STARTING SYSTEM
MG1 and MG2 (Motor Generator No.1 and 2) have been adopted in the charging system, and the convention-
al generator has been discontinued.
Furthermore, due to the adoption of MG1 for the starting system, the conventional starter has been discontin-
ued.

ENGINE ± 1NZ-FXE ENGINE62
ENGINE CONTROL SYSTEM
1. General
The engine control system for the 1NZ-FXE engine has following system.
System
Outline
SFI
Sequential Multiport
Fuel InjectionAn L-type SFI system directly detects the intake air volume with a hot-wire
type mass air flow meter.
ESA
Electronic Spark
AdvanceIgnition timing is determined by the ECM based on signals from various
sensors. The ECM corrects ignition timing in response to engine knocking.
VVT-i
Variable Valve
Timing-intelligentControls the intake camshaft to an optimal valve timing in accordance with
the engine condition.
ETCS-i
Electronic
Throttle Control
System-intelligentOptimally controls the throttle valve opening in accordance with the ECM,
and the conditions of the engine and the vehicle, and comprehensively
controls the ISC and cruise control system.
Fuel Pump Control
Fuel pump operation is controlled by signal from the ECM.

To stop the fuel pump during operation of the SRS airbag.
Oxygen Sensor Heater
ControlMaintains the temperature of the oxygen sensors at an appropriate level to
increase accuracy of detection of the oxygen concentration in the exhaust gas.
Evaporative Emission
Control

The ECM controls the purge flow of evaporative emissions (HC) in the
charcoal canister in accordance with engine conditions.

Using 3 VSVs and a vapor pressure sensor, the ECM detects any
evaporative emission leakage occurring between the fuel tank and the
charcoal canister, and vapor reducing fuel tank through the changes in the
tank pressure. For details, see page 79.
Toyota HCAC System
The ECM controls the VSV (for Toyota HCAC System) to improve the clean
emission performance of the exhaust gas when the temperature of the TWC
is low. For details, see page 58.
Air Conditioning
Cut-Off ControlBy turning the air conditioning compressor OFF in accordance with the
engine condition, drivability is maintained.
Cooling Fan ControlRadiator cooling fan operation is controlled by signals from ECM based on
the engine coolant temperature sensor signal (THW).
HV Immobiliser
Prohibits fuel delivery, ignition, and starting the HV system if an attempt is
made to start the HV system with an invalid ignition key. For details, see page
80.
DiagnosisWhen the ECM detects a malfunction, the ECM diagnoses and memorizes
the failed section.
Fail-SafeWhen the ECM detects a malfunction, the ECM stops or controls the engine
according to the data already stored in memory.

ENGINE ± 1NZ-FXE ENGINE
No.4 INJECTOR
SPARK PLUGS
No.2 INJECTOR
No.1 INJECTOR
No.3 INJECTOR SENSORS ACTUATORS
SFI
#10
CRANKSHAFT POSITION
SENSORNE
CAMSHAFT POSITION
SENSORG2
THROTTLE POSITION SENSORVTA
VTA2
COMBINATION METER
SPD

Vehicle Speed Signal
HEATED OXYGEN SENSOR
(Bank 1, Sensor 1)OX1A
HEATED OXYGEN SENSOR
(Bank 1, Sensor 2)OX1B
AMBIENT TEMP. SENSORTA M
ESA
IGT1

IGT4
IGF
THROTTLE CONTROL
MOTORETCS-i
M
ECM
ENGINE COOLANT TEMP.
SENSORTHW
INTAKE AIR TEMP. SENSORTHA
MASS AIR FLOW METERVG
IGNITION SWITCHIGSW
KNOCK SENSORKNK1
OIL PRESSURE SWITCHMOPS
CAMSHAFT TIMING OIL
CONTROL VALVE OCV
VVT-i
Bank 1, Sensor 2
Bank 1, Sensor 1HT1A
HT1B
#20
#30
#40
OXYGEN SENSOR HEATER
CONTROL
HEATED OXYGEN SENSOR
HEATER
CIRCUIT OPENING RELAYFUEL PUMP CONTROLFC
IGNITION COIL
with IGNITER
63
2. Construction
The configuration of the engine control system in the INZ-FXE engine is shown in the following chart.
(Continued)

ENGINE ± 1NZ-FXE ENGINE
ECM
EFI MAIN RELAY BATTERY+B BATT, BM
HTE
ETH
SPHV
ESTP
GO HV ECU
(Hybrid Vehicle Control ECU)
VACUUM SENSOR
(for TOYOTA HCAC SYSTEM)ACCELERATOR PEDAL
POSITION SENSORHCLS
VAPOR PRESSURE SENSORPTNK VPA 1, 2
DATA LINK CONNECTOR 3SIL
TC
AIR CONDITIONING ECU AIR CONDITIONING CUT-
OFF CONTROL
ACT
COOLING FAN RELAYCOOLING FAN
CONTROLFA N
VSV (for EVAP) EVAP CONTROLEVP1
VSV (for CANISTER
CLOSED VALVE) CCV
VSV (for PURGE FLOW
SWITCHING VALVE)TBP
METER ECU
AIR CONDITIONING ECU
DISPLAY ECU
BODY ECU
VSV
(for TOYOTA HCAC SYSTEM)
EFI MAIN RELAY
MALFUNCTION INDICATOR
LAMP MPX1
NEO
MPX2
HCC
MREL
W
64

ENGINE ± 1NZ-FXE ENGINE
182EG22
Circuit
Opening
Relay
VSV
(for
EVAP)
Intake
Air Temp.
SensorThrottle
Position
Sensor
ECMHV
ECU
Accelera-
tor Pedal
Position
Sensor
Cooling
Fan Relay
Throttle
Control
Motor
Igniter
Camshaft Position Sensor
Knock
Sensor
Mass Air
Flow Meter
VSV
(for Toyota
HCAC
System)Vacuum
Sensor
(for Toyota
HCAC
System)
Crankshaft
Position Sensor Injector
Camshaft
Timing
Oil Con-
trol Valve
Engine
Coolant
Te m p .
Sensor
TWC
Heated Oxygen
Sensor (Bank 1,
Sensor 1)
Heated Oxygen
Sensor (Bank 1,
Sensor 2)
Actuator (for HC
Adsorber)
TWC (with HC
Adsorber)
VSV (for Purge Flow
Switching Valve)
Vapor Pressure Sensor
VSV (for Canister Closed Valve)
Charcoal
Canister
Fuel Pump65
3. Engine Control System Diagram

ENGINE ± 1NZ-FXE ENGINE
182EG23
VSV (for TOYOTA
HCAC System)VSV (for EVAP)Oil Control Valve
ECMIgnition Coil
with IgniterVSV (for Purge Flow Switching Valve)
Charcoal Canister
Vapor
Pressure
Sensor
Trap Filter
VSV (for Canister
Closed Valve) DLC 3
Heated Oxygen Sensor
(Bank 1, Sensor 2)
Heated Oxygen Sensor
(Bank 1, Sensor 1) Engien Coolant
Temp. Sensor Camshaft
Position
Sensor
Injector Crankshaft
Position
Sensor Knock
Sensor Throttle
Control
Motor Mass Air
Flow Meter 66
4. Layout of Components

ENGINE ± 1NZ-FXE ENGINE
182EG24
VVT-i Controller
ECM
Camshaft Position
Sensor
Camshaft Timing
Oil Control Valve Crankshaft
Position
Sensor67
5. Main Components of Engine Control System
The main components of the 1NZ-FXE engine control system are as follows:
Components
OutlineQuantity
Mass Air Flow MeterHot-Wire Type1
Crankshaft Position Sensor (Rotor's Teeth)Pick-Up Coil Type (36-2)1
Camshaft Position Sensor (Rotor's Teeth)Pick-Up Coil Type (3)1
Throttle Position SensorLinear Type (Double)1
Knock SensorBuilt-In Piezoelectric Element Type1
Oxygen Sensor
Heated Oxygen Sensor
(Bank 1, Sensor 1)
(Bank 1, Sensor 2)
2
Injector12-Hole Type4
6. VVT-i (Variable Valve Timing-intelligent) System
General
The VVT-i system is designed to control the intake camshaft within a wide range of 43 (of crankshaft
angle) to provide a valve timing that is optimally suited to the engine condition, thus realizing improved
torque in all the speed ranges and fuel economy, and reduce exhaust emissions.