2001 TOYOTA PRIUS navigation

BODY ELECTRICAL ± ACCESSORIES179
5. GPS (Global Positioning System) Voice Navigation
General
The GPS (Global Positioning System) function receives, via an GPS antenna, the signals that are trans-
mitted from the GPS satellites located in space at an approximate altitude of 20,000 km, in order to deter-
mine the vehicle's present position.
The GPS voice navigation function combines the radiowave navigation system that determines the pres-
ent position through the GPS signals, and the self-contained navigation system that detects the driven
distance and the direction of travel through the speed sensors and the gyro sensor that is contained in the
navigation ECU. The GPS voice navigation function is a high-precision navigation system that indicates
the vehicle position on the map display on the DVD and guides the route from the present position to the
destination on a map and pictogram and through voice instructions.
The multi-information display shows the data that has been calculated by the radiowave navigation sys-
tem and the self-contained navigation system.
Construction and Operation
The GPS voice navigation function consists of the following components:
GPS Antenna
Speed Sensor
GPS Receiver (contained in the navigation ECU)
Gyro Sensor (contained in the navigation ECU)
Navigation ECU
Speaker
For details on the basic operation of the GPS antenna and the navigation ECU, see page 175.
1) Speed Sensor
The navigation ECU will receive the vehicle speed signal directly from the meter ECU.
2) GPS Receiver
The GPS receiver demodulates the signals that are received by the GPS antenna from the satellites and
outputs them to the navigation ECU.

BODY ELECTRICAL ± ACCESSORIES
Vibration DirecitonTurning Axis Center
Coriolis Force
Detection Portion
182BE49
180
3) Gyro Sensor
The gyro sensor is designed to detect the yaw rate of vertical axis turn of the vehicle and installed in the
Navigation ECU.
The gyro sensor has a turning-fork shape type piezoelectric ceramic piece inside. This piezoelectric ce-
ramic piece deforms by charging voltage and generates voltage by deforming with force.
The piezoelectric ceramic piece inside the gyro sensor is vibrated by the driving circuit and when the
vehicle turns (when the detection portion turns to the axis direction), coriolis force is added to the detec-
tion portion. With this force, the detection portion is twisted. The voltage generated by this twisting is
signal-processed inside the gyro sensor and outputted.
Navigation ECU receives this signal and judges the yaw rate of the vehicle.
4) Speaker
Outputs the sound signals that are transmitted from the power amplifier. Also outputs the navigation
voice instructions via the front left speaker.

BODY ELECTRICAL ± ACCESSORIES
151LBE24
GPS Sateilites
Difference
Difference
Difference
Difference181
5) Detecting the Vehicle Position
The navigation ECU calculates the position based on the principle of a 3-point measurement.
The GPS satellites are equipped with high-precision clocks. Thus, the satellites are able to transmit con-
tinuous orbit signals and radiowave transmission time signals.
The navigation ECU also contains a clock, which can understand the radiowave time signals that are re-
ceived from the satellites.
As a result, the length of time that is taken by the radiowaves to arrive from the satellites to the antenna
can be determined. Thus, the lengths of time that elapse for the radiowaves of the 4 satellites to reach
the antenna are measured. Each of these lengths of time are multiplied by the luminous flux (the rate of
transmission of luminous energy: approximately 300,000 km per second), the results of which are the
distances from the satellites to the antenna. Because the positions of the GPS satellites are known by their
signals, the receiving point (vehicle position) can be rendered as the point in which the 4 spheres (of
which the centers are the respective satellites) converge.
However, due to the differences that exist between the clocks of the satellite and the ECU, the 4 spheres
do not converge at a single point. Therefore, the ECU uses another satellite to calculate the point at which
the 4 spheres converge at a single point and corrects its internal clock. As a result, the ECU determines
the vehicle position and adjusts its internal clock to the clocks of the satellites.

IN05Y±22
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±29
29 Author: Date:
2001 PRIUS (RM778U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the PRIUS. In general, the ECU controlled system
is considered to be a very intricate system requiring a high level of technical knowledge and expert skill to
troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshooting of
these systems is not complex. If you have adequate understanding of the system and a basic knowledge
of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This
manual is designed through emphasis of the above standpoint to help service technicians perform accurate
and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
6. EngineDI±1
7. Hybrid Vehicle Control SystemDI±174
8. HV Battery Control SystemDI±312
9. Anti±Lock Brake System With EBD & RBSDI±351
10.Electric Motor Power SteeringDI±452
11. Supplemental Restraint SystemDI±495
12.Cruise Control SystemDI±640
13.Combination Meter SystemDI±662
14.Body Control SystemDI±678
15.Driver Door Control SystemDI±730
16.Multiplex Communication SystemDI±750
17.Navigation SystemDI±789
18.Air Conditioning SystemDI±864
FOR USING OBD II SCAN TOOL OR TOYOTA HAND±HELD TESTER

Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.

If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Bus
line) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.

IN±32± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
2001 PRIUS (RM778U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the PRIUS fulfills various functions. The first function is the Diagnostic Trouble
Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU memory
at the time of occurrence, to be output by the technician during troubleshooting. Another function is the Input
Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the PRIUS.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
Engine (with Check
Mode)
Hybrid Vehicle Control System
HV Battery Control System (with Check
Mode)
Anti±Lock Brake System With EBD & RBS
Electric Motor Power Steering
Supplemental Restraint System
Cruise Control System
Multiplex Communication System
Navigation System
Air Conditioning System

DI82J±02
Prius Problem Check Sheet
Vehicle
Specifications
Please fill in the blanks within bold frame.Name of DealerPerson in Charge at
HeadquartersPerson in Charge
at Dealer
Model CodeOffice
Vehicle Delivery Date
Frame No.
Unit No. etc.
Option . . . :
( ) Navigation (equipped by ( ) MOP ( ) dealer) ( ) Cold climate specification
( ) others( )Problem Occurrence Date
Service Entry Date NHW11±
. .
. .Registration datemiles
. .
Contents of complaint (Status when and before/after occurring in
the order of events as correct as possible)Characteristics of Customer
Gender
Age
Occupation
Vehicle used before
Main use area
Frequency in use
Others times/day or
week or month
Status of engineOthers
Interview Results
( ) Male ( ) Female
suburbs ( ) %
Others ( ) ( ) %
city area ( ) %
mountain area ( ) %
Driving ConditionRoad Condition
Vehicle Condition
Vehicle Speed
km/h
( ) when starting
( ) when according
( ) When
normal driving
( ) when
decelerating
( ) when braking
( ) when shopping
( ) when parking
( ) when turning
( ) when
ABS actuating
( ) others
( )( ) flat road
( ) up hill ( ) down
hill incline of
° /%
distance
km
( ) dry paved road
( ) wet paved road
( ) rough paved road
( ) unpaved road
( ) snowy/frozen
road
( ) bump/curb
( ) others
( )( ) when starting
( ) right after
starting
( ) until min.
after starting
( ) until min.
after starting
of driving
( ) when shopping
system
( ) while shopping
engine
( ) when starting
engine
( ) when revolving
engineHV Battery
indication
( ) 4/4 ( ) 3/4
( ) 2/4 ( ) 1/4
( ) unidentified
Shift position
(indication)
( ) P ( ) R ( ) N
( ) D ( ) B
( ) when operating
"Weather:
A/C status
( ) no indication
( ) unidentified
( ) A/C ( ) FULL
( ) OFF
( ) unidentifiedWarning light
(MIL)
( ) ON ( ) OFF
( ) PS
( ) main battery
( ) HV!
( ) engine
( ) charge
( ) output
control
( ) brake
( ) ABS
( ) others
( )
Temperature:
°C
Brake operation
( ) brake slowly
( ) Brake suddenly
( ) use two pedals
system
Frequency in
occurrence
( ) always
( ) sometimes
( ) only once
Fuel level
( ) segmentsmphOdometer Reading
mph
°F km
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±175
2001 PRIUS (RM778U)
CUSTOMER PROBLEM ANALYSIS CHECK

DI2VS±03
Prius Problem Check Sheet
Vehicle
Specifications
Please fill in the blanks within bold frame.Name of DealerPerson in Charge at
HeadquartersPerson in Charge
at Dealer
Model CodeOffice
Vehicle Delivery Date
Frame No.
Unit No. etc.
Option . . . :
( ) Navigation (equipped by ( ) MOP ( ) dealer) ( ) Cold climate specification
( ) others( )Problem Occurrence Date
Service Entry Date NHW11±
. .
. .Odometer Reading
Registration datekm
. .
Contents of complaint (Status when and before/after occurring in
the order of events as correct as possible)Characteristics of Customer
Gender
Age
Occupation
Vehicle used before
Main use area
Frequency in use
Others times/day or
week or month
Status of engineOthers
Interview Results
( ) Male ( ) Female
suburbs ( ) %
Others ( ) ( ) %
city area ( ) %
mountain area ( ) %
Driving ConditionRoad Condition
Vehicle Condition
Vehicle Speed
km/h
mph
( ) when starting
( ) when according
( ) When
normal driving
( ) when
decelerating
( ) when braking
( ) when shopping
( ) when parking
( ) when turning
( ) when
ABS actuating
( ) others
( )( ) flat road
( ) up hill ( ) down
hill incline of
° /%
distance
km
mph
( ) dry paved road
( ) wet paved road
( ) rough paved road
( ) unpaved road
( ) snowy/frozen
road
( ) bump/curb
( ) others
( )( ) when starting
( ) right after
starting
( ) until min.
after starting
( ) until min.
after starting
of driving
( ) when shopping
system
( ) while shopping
engine
( ) when starting
engine
( ) when revolving
engineHV Battery
indication
( ) 4/4 ( ) 3/4
( ) 2/4 ( ) 1/4
( ) unidentified
Shift position
(indication)
( ) P ( ) R ( ) N
( ) D ( ) B
( ) when operating
"Weather:
A/C status
( ) no indication
( ) unidentified
( ) A/C ( ) FULL
( ) OFF
( ) unidentifiedWarning light
(MIL)
( ) ON ( ) OFF
( ) PS
( ) main battery
( ) HV!
( ) engine
( ) charge
( ) output
control
( ) brake
( ) ABS
( ) others
( )
Temperature:
°C
Brake operation
( ) brake slowly
( ) Brake suddenly
( ) use two pedals
system
Frequency in
occurrence
( ) always
( ) sometimes
( ) only once
miles
°F
Fuel level
( ) segments
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±313
2001 PRIUS (RM778U)
CUSTOMER PROBLEM ANALYSIS CHECK

DI7OR±01
I17101
Navigation system normal operation
to 2. SYSTEM CHECK MODE SCREEN
to 4. DISPLAY
CHECK MODE SCREEN to 3. NAVIGATION
CHECK MODE SCREENDiagnosis start±up. (refer to next page)
HINT:
When Diagnosis Sys-
tem mode is started,
system check is per-
formed at first and the
check result is dis-
played. DI±796
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)
PRE±CHECK
1. DIAGNOSIS SYSTEM MODE
HINT:
Diagnosis System Mode is operated as follows.