fuel pressure TOYOTA PRIUS 2001 Service Repair Manual

ENGINE ± 1NZ-FXE ENGINE
182EG05
FrontExhaust Side
Crankshaft Center
Bore Center
8 mm
Intake Side12 mm
182EG06
Taper Squish Shape47
2. Cylinder Block

A cylinder block made of aluminum alloy has been adopted to realize a significant amount of weight reduc-
tion.

A water pump swirl chamber and an inlet passage to the pump are provided in the cylinder block.

The rear portion of the cylinder block has been shaped conically to improve the coupling rigidity with the
transaxle.

Through the adoption of the offset crankshaft, the bore center has been shifted 12 mm towards the intake,
in relation to the crankshaft center. Thus, the side force when the maximum pressure is applied has been
reduced and the heat efficiency has been improved. And as a result, fuel economy has been improved.

Through the use of a thin-walled cast iron liner in the cylinder bore, a distance of 8 mm between the bores
has been realized, resulting in a compact package. This liner is thin, so that boring is not possible.

By discontinuing the use of the rear oil seal retainer and by pressing the rear oil seal into the cylinder block,
a compact package has been realized.
3. Piston

The taper squish shaped piston has been
adopted to improve combustion chamber.

Low-tension piston rings have been adopted to
reduce friction and improve fuel economy and
oil consumption performance.

By increasing the mechining precision of the
cylinder bore diameter, the outer diameter of
the piston has been made into the one type.

ENGINE ± 1NZ-FXE ENGINE
182EG38
Injector
Delivery Pipe
Pressure Regulator
Fuel Tank Fuel Filter
Fuel Pump 58
FUEL SYSTEM
1. Injector
A compact 12-hole type injector has been adopted to improve the atomization of fuel.
2. Fuel Returnless System
This system is to reduce the evaporative emission. As shown below, integrating the pressure regulator and
fuel filter with the fuel pump assembly made it possible to discontinue the return of fuel from the engine area
and prevent temperature rise inside the fuel tank.
3. Quick Connector
Quick connector has been adopted to connect the fuel pipe with the fuel hose to improve serviceability.

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 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
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
182EG34
Air CleanerIntake Air Chamber
VSV
(for EVAP)
ECM
Fresh Air Line
Purge Line
EVAP Line
VSV
(for Purge Flow Switching Valve)
Charcoal Canister
Recircle Line
Vapor Pressure
Sensor
VSV (for Canister Closed Valve)77
9. Evaporative Emission Control
General
A vacuum system has been newly adopted to detect leaks in the evaporative emission control system. This
vacuum system detects leaks by forcefully introducing the purge vacuum into the entire system and moni-
toring the changes in the pressure.
In order to detect evaporative emission leaks from the vapor reducing fuel tank, a density method has been
adopted. This system uses an oxygen sensor to measure the HC density in the exhaust gases in order to detect
leaks.
It consists of the following main conponents:

A VSV (for canister closed valve) has been provided between the fresh air line and the fuel tank.

The VSV (for purge flow switching valve) switches the passages from the charcoal canister to the purge
line and from the fuel tank to the purge line.

A vapor pressure sensor has been provided in the fuel tank in order to further ensure the precision of the
vapor pressure sensor.

DTCs (Diagnostic Trouble Codes) have been added. For details on the DTCs (Diagnostic Trouble
Codes), refer to the 2001 Prius Repair Manual (Pub. No.RM778U).

ENGINE ± 1NZ-FXE ENGINE 78
Operation
Initially, the VSV (for canister closed valve) is closed, and the VSV (for EVAP) is open, enabling the VSV
(for purge flow switching valve) to keep the passage between the charcoal canister and the purge line open.
This causes a vacuum to be applied to the purge line, evaporator line, recirculation line, and the line from
the charcoal canister to the fuel tank.
Next, the VSV (for EVAP) is closed in order to maintain a vacuum from the VSV (for EVAP) to the inside
of the fuel tank. Then, any subsequent changes in the pressure are monitored by the vapor pressure sensor
in order to check for evaporative emission leaks.
Next, the VSV (for canister closed valve) and the VSV (for EVAP) open, enabling the VSV (for purge flow
switching valve) to keep the passage between the fuel tank and the purge line open. Then, the air in the fuel
tank is drawn in by the vacuum of the intake chamber, and the density of HC in the exhaust gases is measured
by the oxygen sensor to detect any leaks.
If a leak is detected, the malfunction indicator lamp (MIL) illuminates to inform the driver. Also, the diag-
nostic trouble code (DTC) can be accessed through the use of a hand-held tester.
For details on the DTCs, refer to the 2001 Prius Repair Manual (Pub. No.RM778U).
10. HV Immobiliser System
The HV immobiliser system has been designed to prevent the vehicle from being stolen. This system uses
a HV ECU that stores the ID code of the authorized ignition key. If an attempt is made to start the HV system
using an unauthorized key, the HV ECU prohibit fuel delivery, ignition, and starting the HD system effective-
ly disabling the engine.
For details see page 184 in the HV Immobiliser System section.
11. Diagnosis System
The diagnostic trouble codes can be output via DLC3 to an OBD-II scan tool or a hand-held tester. For details,
refer to the 2001 Prius Repair Manual (Pub. No.RM778U).

THS (TOYOTA HYBRID SYSTEM)
HV ECUGO
ECM
Engine
Throttle Control
Motor
SPDO
EF1
HTE, ETH
ESA
VVT-i
W
MESTP
Brake Actuator
(Brake Master
Cylinder)
BRAKE ECUBrake Actuator
(Solenoid Valves)
Pressure Sensors
Signal
HV ECU Pressure
BTH
Total Brake Force
RequestedHTB
Regenerative Brake
Force Transmitted29
3. ECM Control
The ECM receives the demand torque and the target rpm which were sent from HV ECU (THE, ETH), and
controls the degree of throttle valve opening, fuel injection timing, ignition time and VVT-i.
In addition, the actual rpm is sent to the HV ECU with GO, and the speed signal from the hybrid transaxle
is received through HV ECU with SPDO.
When the vehicle is stopped, the HV ECU may send an engine stop (ESTP) command to the ECM to reduce
fuel used.
When a malfunction occurs in the system, the ECM activates MIL via the directions from the HV ECU.
4. BRAKE ECU Control
The brake ECU calculates the total braking force needed, based on the master cylinder pressure in the brake
actuator generated when the driver depresses the brake pedal, and sends this valve to the HV ECU.
The HV ECU computes a part for the regeneration brake force from the total braking force, and sends the
result to the brake ECU.
The HV ECU executes to the minus torque to MG2, and carries out the regenerative brake functions.
The brake ECU controls the brake actuator solenoid valves and generates the wheel cylinder pressure, which
is the regenerative brake force subtracted from the total braking force.

BODY ELECTRICAL ± AIR CONDITIONING 172
3) Refrigerant Pressure Malfunction Detection
By monitoring the pressure switch signal, this system can judge the refrigerant pressure to be abnormal,
and turns off the compressor magnetic clutch relay, if the pressure switch remains off.
4) MAX Switch ON Control
a. General
In case of usual air conditioning operation, the air conditioning system shows superior control on cool-
ing performance and fuel efficiency by combining the engine ON / OFF control by the hybrid control
and the air conditioning ON / OFF control.
In this MAX switch ON control, it controls by attaching greater importance to cooling performance of
the air conditioning.