2001 TOYOTA PRIUS transmission

2001 PRIUS (EWD414U)
B
The ºCurrent Flow Chartº section, describes which parts each power source (fuses, fusible links, and circuit breakers)
transmits current to. In the Power Source circuit diagram, the conditions when battery power is supplied to each system
are explained. Since all System Circuit diagrams start from the power source, the power source system must be fully
understood.
Theft Deterrent and Door Lock Control
J POWER SOURCE (Current Flow Chart)
11
1
EA1 1EA2 3
7
EB16
E 6
E 7I 2I 2
I 2
E 7
E 7
E 7
2
1
1
2
2
2
2
2
B
B
W W
B B B B BW±B
B
B
B B±O
B±W
W±B
B±W STARTER RELAY INJECTION RELAY15A HAZ±RADIO7.5A AM250A MAIN 1.25B FL MAIN
BATTERY
WWW
W W W
R W±L
W
W
G±W
G
15A TAIL
20A DEFOG
15A RAD CIGTA I L
RELAY 7.5A DOME 40A DOOR LOCK CB
2 1
1 2
4 8
2 3
3 4
G
W±R
P±L B±Y
B±Y
W±R
AM2 IG2
ACC
IG1AM1W W
W±R
W W
W±B
21
1
1
1
1
2
2
2
2
3
4
3
4 1
2
1
22
1
11
1
IGNITION SW I 8
Battery
30A AM2
2
Starter S 220A RADIO NO.1
10A HORN
15A EFI
7.5A DOMEShort Pin
10A HAZARD
The chart below shows the route by which current flows from the battery to each electrical source
(Fusible Link, Circuit Breaker, Fuse, etc.) and other parts.
Engine Room R/B (See Page 20)
ABS
ABS and Traction Control
Cruise Control
Electronically Controlled Transmission and A/T Indicator
Multiplex Communication System
Cigarette Lighter and Clock
Key Reminder and Seat Belt Warning STOP
Fuse Page
194
214
11 2
System
DOME 20A
10ACombination Meter
Headlight
Interior Light
2
2
6 100A ALT
EB1
POWER SOURCE
Light Auto Turn Off187
180
166
210
230
122
10A ECU±B
5 60A ABS
2
6 Fusible Link Block2
*The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.

2001 PRIUS (EWD414U)
ENGINE CONTROL
This system utilizes an engine control module and maintains overall control of the engine, transmission and so on. An outline
of the engine control is explained here.
1. INPUT SIGNALS
(1) Engine coolant temp. signal circuit
The engine coolant temp. sensor detects the engine coolant temp. and has a built±in thermistor with a resistance which
varies according to the engine coolant temp. thus the engine coolant temp. is input in the form of a control signal into
TERMINAL THW of the engine control module.
(2) Intake air temp. signal circuit
The intake air temp. sensor is installed in the mass air flow meter and detects the intake air temp., which is input as a
control signal into TERMINAL THA of the engine control module.
(3) Oxygen sensor signal circuit
The oxygen density in the exhaust gases is detected and input as a control signal into TERMINALS OX1A and OX1B of
the engine control module.
(4) RPM signal circuit
Camshaft position and crankshaft position are detected by the camshaft position sensor and crankshaft position sensor.
Camshaft position is input as a control signal to TERMINAL G2 of the engine control module, and engine RPM is input
into TERMINAL NE+.
(5) Throttle signal circuit
The throttle position sensor detects the throttle valve opening angle, which is input as a control signal into TERMINALS
VTA and VTA2 of the engine control module.
(6) Vehicle speed signal circuit
The vehicle speed signal from brake ECU, detects the vehicle speed and inputs a control signal into TERMINAL SPD of
the engine control module via the combination meter.
(7) Battery signal circuit
Voltage is constantly applied to TERMINAL BATT of the engine control module. When the ignition SW is turned on, the
voltage for engine control module start±up power supply is applied to TERMINAL +B of the engine control module via
EFI relay.
(8) Engine knock signal circuit
Engine knocking is detected by knock sensor and the signal is input into TERMINAL KNK1 of the engine control module
as a control signal.
2. CONTROL SYSTEM
*SFI system
The SFI system monitors the engine condition through the signals, which are input from each sensor to the engine
control module. The best fuel injection volume is decided based on this data and the program memorized by the engine
control module, and the control signal is output to TERMINALS #10, #20, #30 and #40 of the engine control module to
operate the injector. (Inject the fuel). The SFI system produces control of fuel injection operation by the engine control
module in response to the driving conditions.
*ESA system
The ESA system monitors the engine condition through the signals, which are input to the engine control module from
each sensor. The best ignition timing is detected according to this data and the memorized data in the engine control
module, and the control signal is output to TERMINALS IGT1, IGT2, IGT3 and IGT4. This signal controls the ignition coil
and igniter to provide the best ignition timing for the driving conditions.
*Fuel pump control system
The engine control module operation outputs to TERMINAL FC and controls the CIR OPN relay. Thus controls the fuel
pump drive speed in response to conditions.
3. DIAGNOSIS SYSTEM
With the diagnosis system, when there is a malfunctioning in the engine control module signal system, the malfunction
system is recorded in the memory. The malfunctioning system can then be found by reading the display (Code) of the
malfunction indicator lamp.
4. FAIL±SAFE SYSTEM
When a malfunction occurs in any system, if there is a possibility of engine trouble being caused by continued control based
on the signals from that system, the fail±safe system either controls the system by using data (Standard values) recorded in
the engine control module memory or else stops the engine.
SYSTEM OUTLINE

THS (TOYOTA HYBRID SYSTEM)
THS (TOYOTA HYBRID SYSTEM)
182TH03
Planetary Gear UnitMG1
InverterHV
Battery
MG2
Differential
Gear Unit
Engine
Hybrid Transaxle
Mechanical Power Path
Electrical Path
182TH01
Battery
*
1
Inverter
*
2Engine
Generator Electric Motor
*
1: Direct Current
*2: Alternating Current
182TH02
Battery
Inverter
Engine
Motor / Generator Transmission 22

DESCRIPTION
The hybrid system is a type of powertrain that uses a combination of two types of motive forces, such as an
engine and a motor (MG2). This system is characterized by its skillful use of two types of motive forces ac-
cording to the driving conditions. It maximizes the strengths of each of the motive forces and complements
their weaknesses. Thus, it can achieve a highly responsive, dynamic performance, as well as a dramatic re-
duction in fuel consumption and exhaust gas emissions. The THS can be broadly divided into two systems:
the series hybrid system, and the parallel hybrid system.
± REFERENCE ±
Series Hybrid System
In the series hybrid system, the engine runs a genera-
tor, and the generated electricity enables the electric
motor to drive the wheels. This type of vehicle can be
described as an electric car that is equipped with an
engine-driven generator.
Equipped with a low-output engine, the engine is op-
erated at a practically constant speed in its most ef-
fective range, in order to efficiently recharge the bat-
tery while the vehicle is in motion.
Parallel Hybrid System
This system uses both the engine and the electric mo-
tor to directly drive the wheels is called the parallel
hybrid system. In addition to supplementing the mo-
tive force of the engine, the electric motor in this sys-
tem can also serve as a generator to recharge the bat-
tery while the vehicle is in motion.

THS (TOYOTA HYBRID SYSTEM)
182TH24
ªREADYº LightOutput Control
Warning Light 26
DRIVING CHARACTERISTICS
Because the Prius uses a parallel series hybrid system, some aspects of its operation may differ from those of
existing automobiles, and may require precautions that are unique to this system.
1. Starting the THS
Make sure that the parking brake is engaged and that the shift lever is in the P position.
While depressing the brake pedal, turn the ignition switch to the START position. After this, the ªREADYº
light flashes.
The engine does not start when the shift lever is in the N position; it can only start in the P position. When
the external air temperature is low, the ªREADYº light may flash longer than usual.
As soon as the engine has started, the ªREADYº light illuminates steadily and a beeping sound is heard.
Several seconds after the engine warms up, the engine stops automatically, provided that the air conditioning
compressor does not need to operate and that the HV battery maintains a proper SOC (state of charge).
2. Start-Off
While keeping the brake pedal depressed, release
the parking brake, and move the shift lever to the
D position.
The vehicle has the same creeping movement as
the conventional automatic transmission vehicles.
Gradually release the brake pedal and slowly de-
press the accelerator pedal to start off.
At this time, the vehicle starts off powered only by
the MG2 (Motor Generator No.2)
NOTICE: The vehicle can be started off, provided that the ªREADYº light remains illuminated, even
if the engine remains stopped.
3. Acceleration
Depress the accelerator pedal to accelerate the vehicle.
If the engine remained stopped during start-off, the engine will start automatically during acceleration.
4. Downhill Driving
Move the shift lever to the B position as necessary in order to simultaneously apply the regenerative brake
and the engine friction brake.
5. Deceleration and Stopping
Depress the brake pedal to decelerate and to stop the vehicle.
Depressing the brake pedal causes the regenerative brake to activate automatically in the D or B position. (In
the regenerative brake system, kinetic energy is converted to electrical energy.) If the engine has warmed up,
the air conditioning compressor does not need to operate, and if the HV battery maintains a proper SOC (state
of charge), the engine stops automatically when the vehicle speed drops-even if the vehicle comes to a stop.
6. Parking
Push down the parking brake pedal, move the shift lever to the P position, and pull out the ignition key.
NOTICE: Make sure to pull out the ignition key after parking the vehicle because the vehicle can be
driven as long as the ªREADYº light remains illuminated even if the engine is stopped.
7. Other Characteristics and Precautions

If a drive wheel slips on slippery terrain, causing the front wheels to spin faster than the rear wheels, the
THS effects control to limit the slippage by restraining the drive force. (This also protects the planetary
gear from damage.)

When the HV battery temperature is too high or low, the output control warning light illuminates, alerting
the driver that output power may be limited.
This is not 2 malfunction. This condition may be corrected by avoiding sudden acceleration /decelaration,
after which the light will go out.

When the vehicle is stopped and the shift lever is in the N position, electricity is not generated even if the
engine is running. If the vehicle remains stopped for a long time, make sure to move the shift lever to the
P position. In heavy traffic, keep the shift lever in the D position.

THS (TOYOTA HYBRID SYSTEM)
182CH05
Stator
Rotor
Speed Sensor (Resolver)
MG1
182CH04
Stator
Rotor
Speed Sensor (Resolver)
MG2
182TH07
N.m
350
300
250
200
150
100
50
0
01000 30002000 50004000 60000 20 40
30
10 kW
Torque
Engine Speed (rpm)Output
Torque
Output
33
MG1 AND MG2 (MOTOR GENERATOR NO.1 AND NO.2)
DESCRIPTION
Both the MG1 and the MG2 are compact, lightweight, and highly efficient alternating current permanent
magnet synchronous type.
Serving as the source of supplemental motive force that provides power assistance to the engine as needed,
the electric motor helps the vehicle achieve excellent dynamic performance, including smooth start-offs
and acceleration. When the regenerative brake is activated, MG2 converts the vehicle's kinetic energy into
electrical energy, which is then stored in the HV battery.
MG1 recharges the HV battery and supplies electrical power to drive MG2. In addition, by regulating the
amount of electrical power generated (thus varying the generator's rpm), MG1 effectively controls the
continuously variable transmission function of the transaxle. MG1 also serves as the starter to start the
engine.

MG2 Specifications 
TypePermanent Magnet
Motor (1CM)
Rated voltage [V]273.6
Maximum output [kW] (rpm)33 / (1040
5600)
Maximum torque [N.m (kgf.m) (rpm)350 / (0
400)
Amperage at maximum torque [A]351
Cooling systemWater-cooled

Performance Curve 

CHASSIS ± P111 HYBRID TRANSAXLE
CHASSIS
182CH01
MG (Motor Generator) 2Power Splitting Device
MG (Motor Generator) 1
Transaxle Damper
Differential Oil Pump79
P111 HYBRID TRANSAXLE
DESCRIPTION
The P111 hybrid transaxle has been newly developed for the hybrid system application.
Containing a MG (Motor Generator) 2 for driving the vehicle and a MG (Motor Generator) 1 for generating
electrical power, the P111 hybrid transaxle uses a continuously variable transmission mechanism with power
splitting device that achieve smooth and quiet operation.

Specifications 
Pl t
The No. of Ring Gear Teeth78
Planetary
GearThe No. of Pinion Gear Teeth23Gear
The No. of Sun Gear Teeth30
Gear Ratio3.905
Number of Links74
ChainDrive Sprocket39
Driven Sprocket36
Counter GearDrive Gear30Counter GearDriven Gear44
Final GearDrive Gear26Final GearDriven Gear75
Fluid Capacity Liters (US qts, Imp.qts)4.6 (4.9, 4.0)
Fluid TypeATF Type T-IV or equivalent

CHASSIS ± P111 HYBRID TRANSAXLE
182CH05
Stator
Rotor
Stator
Rotor
182CH04
81
3. MG (Motor Generator) 1
The MG1 recharges the HV (Hybrid Vehicle) bat-
tery and supplies electrical power to drive the
MG2. In addition, by regulating the amount of
electrical power generated, thus varying the
MG2's speed, the MG1 effectively controls the
continuously variable transmission function of the
transaxle. Connected to the sun gear of the plane-
tary gear unit, MG1 also functions as a starter for
starting the engine.
4. MG (Motor Generator) 2
Serving as the source of supplemental motive
force that provides power assist to the output of the
engine as needed, the electric motor helps the ve-
hicle achieve an excellent dynamic performance
that includes smooth start-offs and acceleration.
Connected to the ring gear in the planetary gear
unit, MG2 is an electric motor that converts the ve-
hicle's kinetic energy that is generated through the
activation of the regenerative brake into electrical
energy, which is then stored in the HV batteries.

CHASSIS ± P111 HYBRID TRANSAXLE
182CH21
Silent Chain
Final Gears
Differential ShaftCounter Gears Engine's Center Shaft 86
6. Reduction Unit
The reduction unit consists of the silent chain, counter gears and final gears.
A silent chain with a small pitch width has been adopted to ensure quiet operation, and the overall length has
been reduced in contrast to the gear-driven mechanism.
The counter gears and final gears teeth have been processed through high-precision housing and their tooth
flanks have been optimized to ensure extremely quiet operation.
The final gears have been optimally allocated to reduce the distance between the engine's center shaft and
the differential shaft, thus resulting in a transmission with a compact package.

DIFFERENTIAL UNIT
For the differential unit, a 2-pinion type that is similar to the differential unit of the conventional transaxle
has been adopted.