1. automotive and vehicles
2. cars
3. hybrid

Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
OBJECTIVES
After studying Chapter 12, the reader should be able to:
1. Identify a Toyota/Lexus hybrid electric vehicle.
2. Explain the operation of the various unique systems found in Toyota/Lexus
hybrid-electric vehicles.
3. List the procedures necessary to disable the high-voltage circuits in
Toyota/Lexus hybrid electric vehicles.
4. Describe how to safely perform routine service on a Toyota/Lexus hybrid
electric vehicle.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
TOYOTA PRIUS
The Prius was first released in Japan in December of 1997 as a 1998 model year.
The second-generation Toyota Prius was released in 2003 as a 2004 model.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The second-generation Prius was equipped with Hybrid Synergy Drive. Both generations of
the Toyota Prius use a 1.5-liter inline four-cylinder engine that uses the Atkinson cycle to
maximize fuel efficiency.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Overall view of the components and their location in a second- generation Toyota
Prius.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Dash Display
The dashboard on the Prius is mostly digital readouts and icons. There is no
tachometer, just a temperature gauge and a fuel level gauge. Near the
speedometer is a “READY” light.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Master Warning Light
Note the triangle-shaped indicator with the exclamation mark in the middle. This is known
as the master warning light.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Energy Monitor
The energy monitor is one of the views available on the large multidisplay.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Consumption screen also shows the average fuel economy over each 5-minute
period up to 30 minutes of history.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Smart Entry and Start Electronic Key (Optional Equipment)
The second-generation Prius may be equipped with an optional smart entry and
start electronic key that appears similar in function and design to the standard
electronic key.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Smart key features include:
Passive (remote) function to lock/unlock the doors and start the vehicle
Wireless transmitter to lock/unlock the doors
Electronic key for starting
Hidden metal cut key to lock/unlock the doors from the driver door lock
Be sure to keep the smart key at least 15 feet from the vehicle when performing repair
procedures. This provides an added margin of safety as it will prevent inadvertent starting of
the vehicle because the normal range is 10 feet.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
When B is selected, the transmission allows the ICE to operate at a higher RPM,
causing it to absorb more of the vehicle’s kinetic energy than it would at lower
RPMs. Drivers looking for the best fuel mileage should not shift into B unless
descending a long, steep grade.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Park on a second-generation Prius is a button rather than a position on the gear
selector.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
“By-Wire” Technology
Numerous systems on the Prius have been designed to incorporate by-wire technology.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Brake-by-wire. The brake system on the Prius includes a stroke simulator that provides a
normal pedal stroke during regenerative braking. There is also a power source backup unit
(second-generation Prius) located next to the auxiliary battery that provides electrical power
to the brake system if the 12-volt battery is damaged or disconnected.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Electronic throttle control. The mechanical linkage between the ICE throttle body and the
accelerator pedal has been eliminated in favor of electronic control.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Shift-by-wire. A special electronic sensor that responds to both lateral and
vertical movement is used as the driver’s shift selector.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Shift control actuator. The only mechanical shifting that takes place in a Prius transmission
is the operation of the parking lock mechanism.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Driving a Toyota Hybrid electric Vehicle
Turning the key (2001-2003 Prius) to the crank position will cause the ICE to start when the
“READY” light illuminates or shortly thereafter. If the ICE is already warmed up, the
“READY” light will illuminate and the ICE will not start. When the “READY” light is lit,
the vehicle is ready to drive, whether the ICE is running or not.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
While depressing the brake pedal, press the POWER button once and Prius will go
straight to READY mode.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
COLD-START EMISSION CONTROLS
HC Adsorber and Catalyst (2001-2003 Prius Only)
When a catalytic converter is cold, it cannot oxidize HC and CO. The HC Adsorber and
Catalyst (HCAC) system utilizes a special catalytic converter assembly that incorporates an
HC adsorber to trap and store unburned hydrocarbons during cold starts.
Once the catalytic converter is up to operating (light off) temperature, the HCAC bypass
valve is opened and HC is purged and sent through the hot catalyst. The bypass valve is also
closed during deceleration to purge any remaining HC from the adsorber.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Coolant Heat Storage System (2004 and Later Prius Only)
The second-generation Prius did not use the HCAC system. A coolant heat storage system in
which heated coolant is stored in a specially designed tank during normal vehicle operation
and is then used to warm the engine intake ports prior to a cold start. Warming the intake
ports and cylinder head before a cold start helps start the ICE more quickly and reduces HC
and CO emissions.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
FUEL SYSTEM COMPONENTS
In order to receive certification as a AT-PZEV vehicle, very strict evaporative emission
standards must be met.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Bladder Fuel Tank
Both generations of the Prius utilize a bladder fuel tank, which stores the fuel in a resin
bladder enclosed in a steel shell. The resin bladder can expand and contract with the fuel.
Fuel level calculations are based on inputs from a fuel gauge sender and ambient temperature
sensor (both located in the tank) plus data from two inclination sensors mounted in the
combination meter ECU.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Closed Fuel Tank System
The closed fuel tank system is only used on the Highlander hybrid and Lexus RX400h
models. A tank close valve (also called a vapor-containment valve) is used to seal the tank
and control vapor flow during purge and refueling. An electric fuel door prevents the fuel
cap from being removed until the tank pressure has been bled through the charcoal canister
and the system is ready for refueling.
During this process, the multi-information display reads “PLEASE WAIT NOW OPENING.”
When the system has finished depressurizing, it unlocks the fuel door and the display shows
“REFUEL READY.”
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
HIGH-VOLTAGE BATTERY PACK
Each NiMH cell produces 1.2 volts; therefore, one module equals 7.2 volts. For
the first-generation Prius, 38 modules were installed in series producing 273.6
volts.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Toyota HV Battery Specifications
Vehicle Models
Battery Construction
Raw Battery Weight
Battery Assembly
Weight
2 001-2003 Prius
1.2-volt cells in banks
of 6 × 38 modules =
273.6 volts
93 lbs (42 kg)
115 lbs (19 kg)
2004 and later Prius
1.2-volt cells in banks
of 6 × 28 modules =
201.6 volts
64 lbs (29 kg)
86 lbs (39 kg)
Highlander Hybrid
Lexus RX400h
1.2-volt cells in banks
of 8 × 30 modules =
288.0 volts
100 lbs (45 kg)
152 lbs (69 kg)
Camry Hybrid
1.2 volt cells in banks of
6 × 34 modules = 244.8
volts
n/a
n/a
Lexus GS450h
1.2 volt cells in banks of
6 × 40 modules = 288
volts
n/a
n/a
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
A first-generation Prius battery pack contains 38 modules, wiring, a system main
relay (SMR), computer, a manual disconnect service plug, and a strong metal box
to contain everything.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
HV Battery Cooling
The high-voltage battery pack is air cooled and utilizes a fan and ducting in the rear of the
vehicle for circulating cabin air through the battery assembly. The cooling air can exit
outside the vehicle or inside depending on the air pressure in the vehicle cabin.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
HV Battery Diagnosis and Service
The warranty of the battery pack varies by manufacturer but typically is covered for eight
years or 100,000 miles.
Environmental concerns regarding battery disposal were addressed prior to releasing hybrids
in the United States by requiring a “cradle-to-grave” process. An 800 telephone number is
located on the battery case or under the hood, and this number should be called when an endof-life NiMH battery assembly needs to be recycled.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Replacing the HV Battery Pack
When replacing a battery pack, the entire box is replaced as a unit. It weighs about 115 lbs
(52 kg) and should be handled carefully as high voltage is contained inside.
The high-voltage battery system must be disabled before attempting any system repairs. Be
sure to wear the appropriate personal protective equipment (PPE) and follow the
manufacturer-specified procedures.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
THE TOYOTA HYBRID SYSTEM
The Toyota Hybrid System (THS), as used in both generations of the Prius,
consists of one planetary gearset and two electric machines. The planetary gearset
is known as a power-split device, because it splits power from the ICE and uses it
for moving the vehicle and for generating electrical power.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
One electric machine is attached to the planetary sun gear and is called motorgenerator 1 (abbreviated MG1). The second electric machine is attached to the
planetary ring gear and is labeled motor-generator 2 (abbreviated MG2). The ICE
is also connected to the planetary gearset through the planet carrier.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
During operation, each motor-generator fulfills two primary functions:
MG1 is used to start the internal combustion engine and generate electricity for charging the
high-voltage batteries, as well as driving MG2.
MG2 is used to propel the vehicle and generate electricity during slowing and braking
(regenerative braking). MG2 is connected directly to the drive wheels at all times.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Four-wheel-drive versions of the Highlander Hybrid and Lexus RX400h use a
third electric machine known as MGR. MGR is connected to the rear wheels and
is used to propel the vehicle forward and backward as well as for regenerative
braking.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Inverter Assembly
Control of the motor-generators in the Toyota Hybrid System is accomplished
using the inverter assembly located in the ICE compartment.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
1. Inverter. Converts high-voltage DC into three-phase AC to power MG1, MG2, and
MGR.
2. DC-DC converter. Converts high-voltage DC to 12-VDC to power the vehicle auxiliary
systems.
3. Boost converter.
4. A/C compressor inverter.
5. Cooling system.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
LEXUS RX400h/TOYOTA HIGHLANDER HYBRID
The Lexus RX400h is a strong hybrid, which means that it is capable of operating in electriconly or gas-engine-only mode, as well as a mode that combines the power of the gas engine
and electric motor.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The hybrid system uses a 288-volt DC nickel metal hydride (Ni-MH) battery pack
that is located under the rear seat.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The battery power is directed through a boost converter that raises the voltage to
650 volts DC. An inverter changes this to 650 volts AC for use by a frontmounted 123-kW electric motor that turns as high as 12,400 RPM.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The RX 400h four-wheel drive (4WD) system uses a separate 50-kW electric
motor (MGR) at the rear that provides up to 96 lb-ft of additional drive torque.
MGR is integrated into the rear-drive unit with a differential in an independent
rear suspension configuration. The system electronically varies front and rear
torque distribution depending on traction conditions.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Vehicle Dynamic Integrated Management (VDIM)
VDIM also interfaces with the Electronic Throttle Control (ETC) system and the Electronic
Power Steering (EPS) system to optimize steering assist for each situation.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The EPS uses a brushless-type DC motor and gear reduction system built into the
steering gear housing to provide steering assist.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Driving the RX 400h
All of the comfort and luxury found inside the RX 330 is present in the RX 400h, with a few
changes, including:
In place of a traditional tachometer, the RX 400h has a power meter that displays the level of
power generated by the hybrid power train.
The driver can also monitor the gas-electric power distribution on the multi-information
display or on the optional navigation system's 7-inch touch-panel display screen.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
TOYOTA CAMRY HYBRID
The Toyota Camry Hybrid features a 2.4-liter inline four-cylinder ICE using the
Atkinson cycle. The Camry Hybrid is a front-wheel-drive THS II configuration.
The package includes a 105-kW electric motor and a high-voltage battery pack
that delivers a peak of 45 hp.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The high-voltage battery pack produces 244 volts and consists of 34 nickel metal
hydride modules, each of which contains six 1.2-volt cells. The battery pack is
located behind the rear passenger seat backs.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The 12-volt auxiliary battery is located on the passenger side of the trunk area.
The inverter assembly incorporates a boost converter that raises the 244 volts DC
from the battery pack to 650 volts DC for higher motor efficiency.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
LEXUS GS450h
The Lexus GS450h is a rear-wheel-drive sedan using a V-6 ICE and a Hybrid Synergy Drive
transmission. The transmission incorporates a power-split planetary gear unit along with a
two-stage motor speed reduction planetary. The second planetary can switch between two
ranges and will vary the speed of MG2 according to vehicle speed and torque requirements.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
MAINTENANCE AND SERVICE PROCEDURES
Care should be taken when driving a Toyota/Lexus hybrid in and around the shop because
they can be driven using electric power only. Known as stealth or quiet mode, this means
that the vehicle can be moving yet no sound will be heard.
The ICE can start anytime the READY indicator is illuminated. Be sure that the READY
light is out before performing any vehicle service.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Disabling the High-Voltage System
The following steps must be performed prior to servicing the high-voltage system on a
Toyota hybrid electric vehicle:
1. Turn the ignition system OFF.
2. Disconnect the negative battery cable from the auxiliary battery.
3. While wearing high-voltage linesman’s gloves with leather outer gloves, remove the
orange service plug.
4. Take steps to make sure that the service plug cannot be installed by another service
technician while you are servicing the vehicle. This can be done by securing the service plug
on your person or in a special lock box.
5. After removing the service plug, wait five minutes before touching any part of the highvoltage system. Verify that the system is de-energized by measuring system voltage with a
digital multimeter (DMM).
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
The 2004 and later Prius has a service plug that requires two steps to properly
reinstall it in the battery pack connector. The handle (lever) on the plug must be
rotated to the right as the plug is being installed.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Testing for Proper Insulation
The Toyota Hybrid System monitors the voltage on the body and will disconnect
the high-voltage source if a fault is indicated.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
A special tester, such as the Fluke model 1587, is required to test if any of the
high- voltage circuits are making contact with the body or ground of the vehicle.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Scan Tool. While some aftermarket scan tools can access hybrid PIDs and DTCs
and perform some bi-directional tests, there is nothing that outperforms the factory
scan tool for the specific vehicle. Toyota’s Diagnostic Tester will access all
available vehicle information and perform all diagnostic testing on the Toyota
Hybrid System.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Rubber gloves were used to remove the large orange service plug.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
Routine Service
The CVT requires periodic transmission fluid replacement. Be sure to use the
factory- recommended fluid. Also, check the fluid level of the inverter coolant as
it provides cooling for the ATF as well. The first-generation Prius used Toyota’s
Long Life Coolant, which was red in color.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
SUMMARY
1. The first-generation Prius was introduced in 2001 in the United States and the second
generation was released in 2003 as a 2004 model.
2. The Prius engine uses the Atkinson cycle and displaces 1.5 liters.
3. The THS inverter is cooled by the same heat exchanger as the transaxle.
4. The Prius is ready to be driven when the READY light is on steady (steady ready).
5. The high-voltage battery packs on Toyota hybrids are air cooled using vents on the outside
or alongside the rear seat.
6. The Lexus RX400h has an optional rear motor, giving the vehicle four-wheel-drive
capability.
7. Care should be taken when driving a Toyota hybrid in parking lots or at slow speeds in or
around the shop because it operates on battery power alone under these conditions and
others may not hear the vehicle approach.
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458
REVIEW QUESTIONS
1. What is unique about starting a Prius?
2. What are the functions of the inverter in a Toyota HEV?
3. What is the procedure for disconnecting the high-voltage circuits on a Toyota HEV?
4. What are the precautions when working on Toyota hybrid vehicles?
Hybrid and Alternative Fuel Vehicles
By James D Halderman and Tony Martin
© 2009 Pearson Education, Inc.
Pearson Prentice Hall
Upper Saddle River, NJ 07458