2001 TOYOTA PRIUS relay

BODY ELECTRICAL ± LIGHTING
151LBE68151LBE67
Multi-Reflector Type HeadlightConventional Headlight Reflector
(Multiple Parabolic Shape)
Headlight Bulb
Headlight Bulb
Lens
Light DistributionReflector
(Rotating Parabolic Shape)
Headlight Bulb
Lens Cut
Lens
Light Distribution
182BE03
From
BatteryDimmer Relay
Headlight
Relay
Parking
Brake Switch
H-LP DIM
PKBDaytime
Running
Light Relay
DRL
From
BatteryEH
HILO HI
LO
No.4
Daytime
Running
Light Relay
144
LIGHTING
HEADLIGHTS
The prius has newly adopted the multi-reflector headlights. Conventional headlights accomplish the dispersion
and distribution of the light that is emitted by the bulbs through the lens cut pattern. However, with the multi-reflec-
tor type headlights, the light from the bulbs is dispersed and distributed through multiple parabolic shaped reflec-
tors. As a result, the lens cut pattern is no longer provided in the center of the lens, thus realizing a clear look.

Light Distribution Diagram 
DAYTIME RUNNING LIGHT SYSTEM
The daytime running light system is adopted for Canada model as standard and U.S.A. model as optional
equipment. This system is designed to automatically activate the headlights (dimmed low beams) during the
daytime to keep the car highly visible to other vehicles.
This system is controlled by a semi-conductor relay circuit (daytime running light relay).

BODY ELECTRICAL ± AIR CONDITIONING
182BE31
Tentative Damper Opening Angle
(During 2-Way Flow Mode)
Damper
Opening
Recirculation /
Fresh Air
SwitchingFresh
Air
2-Way
Flow
MAX HOT
182BE33
A / C SwitchMAX
Switch171
Air Inlet Control System
1) Manual Control
Drives the air inlet servomotor according to
the operation of the air inlet control switch and
fixes the dampers in the FRESH or RECIRC
position.
The 2-way flow mode control switches the re-
circulation / fresh-air function in accordance
with the opening of the air mix damper, calcu-
lates the target opening of the damper, and ro-
tates the servomotor.
2) Battery ECU Forced Fresh Air Mode
When the air conditioning ECU receives the forced fresh air mode signal from the battery ECU via the
HV ECU and the ECM, the damper forcefully switches to the FRESH mode.
3) DEF, FOOT / DEF Mode Control
When the mode switching switch is switched to FOOT / DEF mode from DEF mode or other than
FOOT / DEF mode, air conditioning ECU switches to FRESH mode forcibly.
Also, when the mode switching switch is switched to DEF mode from other than DEF mode, air condi-
tioning ECU turns MAX mode ON and switched to FRESH mode forcibly.
Compressor Control System
1) OFF Control
Turns OFF the magnetic clutch of the compressor when the conditions for turning the blower motor OFF
during warm-up control have been met.
2) Compressor Lock Judgment
When the magnetic clutch is ON, if the air
conditioning ECU judges that the compressor
has been locked, it turns OFF the magnetic
clutch relay and flashes the indicator lamp in
the A / C or MAX switch. The conditions in
which the ECU judges the compressor to have
locked are when a slippage rate of 80% or
more has been continued for 3 seconds or
more.

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.

BODY ELECTRICAL ± ACCESSORIES
182BE41
RRP DBody
ECUUARTPower
Window
Master
SwitchDoor Control
Switch (Manual)
Door Control
Switch (Key-linked)
169BE10
Key Unlock
Warning SwitchDoor Courtesy
Switch
Door Lock
MotorsBody
ECU
Serial Data Link
Wireless Door
Control Receiver
Horn
RelayHeadlight
RelayTaillight
RelayTransmitter183
DOOR LOCK CONTROL SYSTEM
The door lock control system has the following features:
This system has a ªkey-linked lock and unlockº, ªkey-confine preventionº and ªmanual unlock prohibi-
tionº functions.
A 2-step unlock function is provided to unlock the driver's door by turning the key cylinder first and to
unlock passenger's door by turning it the second time.
The control of this system is effected by the body ECU. The door lock control signal from the driver's door
is transmitted from the power window master switch to the body ECU through the UART (Universal
Asynchronous Receiver Transmitter).
If you unlock using the ignition key from the conditions in which all the doors are locked, the dome light
will be lighted.

System Diagram 
WIRELESS DOOR LOCK REMOTE CONTROL SYSTEM
The wireless door lock remote control system has the following features:
In this system, the wireless door control receiver performs the code identification process and the body
ECU effects the door lock control. Serial data link is provided for communication between the wireless
door control receiver and the body ECU.
A key-holder type transmitter has been adopted, and it contains the following three switches: the door lock
switch, door unlock switch, and panic switch.
A rolling code system, in which the signal configuration changes each time when a signal is transmitted
by the transmitter, has been adopted.
Panic alarm operation has been adopted.
The verification light function has been adopted. When the transmitter is used to lock or unlock the doors,
this function flashes the taillights to inform that the operation has been completed. However, at the time
of unlocking, the dome light will be lighted.

BODY ELECTRICAL ± ACCESSORIES
182BE43
DKUL
DKL
LSWD
Power
Window
Master
Switch
Ignition Key SW
From
BatteryIG
LSWP
LSR
KSW
DCTY
PCTY
RCTY
LCTY
HCTY
LUG
Courtesy
Switches
PKL
PKUL
Door Lock Motors
RRP D
Body
ECU
From Battery
Headlight
RelayTaillight
RelayHorn
Relay
HRLY
TRLYTo
HeadlightTo
Taillight
To
Vehicles
Horn
HR
From Battery
Interior
Light
Interior
Light
Relay
Security
Horn
Wireless
Door Control
Receiver
MPX
INDECM
Security
Indicator
185
THEFT DETERRENT SYSTEM
1. General
The theft deterrent system uses the door lock control system components and some other parts. When
somebody attempts to forcibly enter the vehicle or open the engine hood or luggage compartment door
without a key, or when the battery terminals are removed and reconnected, the theft deterrent system
sounds the vehicle's horn, security horn and flashes the headlights, taillights, hazard lights and interior
light for about one minute to alert. At the same time, it locks all the doors.
The control of this system is effected by the body ECU.

Wiring Diagram 

BODY ELECTRICAL ± ACCESSORIES
Non-Alert State
Alert State
Alert Preparation State
Alarm State
Condition (3) Condition (1)
Condition (5) Condition (2)
Condition (6)
Condition (4)
Condition (5) 186

List of Input / Output Signals 
Terminal
NameOutlineTerminal
NameOutline
DKLDriver's door key lock signalLCTYRear left door courtesy switch status
signal
DKULDriver's door key unlock signalHCTYHood courtesy switch status signal
LSWDDriver's door lock position switch
signalLUGLuggage compartment door courtesy
switch status signal
IGIgnition key switch status signalPKLFront passenger door key lock signal
LSWPFront passenger door lock position
switch signalPKULFront passenger door key unlock
signal
LSRRear left door lock position switch
signalHRLYOutput signal to headlight relay
KSWIgnition key cylinder's key
presence / absence signalTRLYOutput signal to taillight relay
DCTYDriver's door courtesy switch status
signalHROutput signal to vehicle horn relay
PCTYFront passenger door courtesy switch
status signalMPXMultiplex Communication (BEAN)
RCTYRear right door courtesy switch
status signalINDOutput signal to security indicator
2. Operation
Non-Alert State: When the security function is inactive
Without having the ignition key in the ignition key cylinder, if any one of the conditions listed below exists,
the system transfers to the alert preparation state.
Condition (1)
When the doors, engine hood, and luggage compartment door are all closed, the ignition key is used to
lock all doors.
When the doors, engine hood, and luggage compartment door are all closed, the wireless door lock re-
mote control system is used to lock all doors.
When all doors are locked, if any door, engine hood, or luggage compartment door is changed from ªcloseº
to ªopenº, and ªcloseº again, all doors, engine hood, and luggage compartment door will be locked.
Alert Preparation State: a delay time until the alert state
The system transfers to the alert state if the condition (2) listed below is met, and to the non-alert state if one
of the conditions (3) is met.

IN0253
WRONG CORRECT
IN0252
WRONG CORRECT IN±6
± INTRODUCTIONREPAIR INSTRUCTIONS
6 Author: Date:
2001 PRIUS (RM778U)
(k) Care must be taken when jacking up and supporting the
vehicle. Be sure to lift and support the vehicle at the prop-
er locations (See page IN±8).
Cancel the parking brake on the pedal place and
shift the transmission in N position.
When jacking up the front wheels of the vehicle at
first place stoppers behind the rear wheels.
When jacking up the rear wheels of the vehicle at
first place stoppers before the front wheels.
When either the front or rear wheels only should be
jacked up, set rigid racks and place stoppers in front
and behind the other wheels on the ground.
After the vehicle is jacked up, be sure to support it
on rigid racks . It is extremely dangerous to do any
work on a vehicle raised on a jack alone, even for
a small job that can be finished quickly.
(l) Observe the following precautions to avoid damage to the
following parts:
(1) Do not open the cover or case of the ECU unless
absolutely necessary. (If the IC terminals are
touched, the IC may be destroyed by static electric-
ity.)
(2) To disconnect vacuum hoses, pull off the end, not
the middle of the hose.
(3) To pull apart electrical connectors, pull on the con-
nector itself, not the wires.
(4) Be careful not to drop electrical components, such
as sensors or relays. If they are dropped on a hard
floor, they should be replaced and not reused.
(5) When steam cleaning an engine, protect the elec-
tronic components, air filter and emission±related
components from water.
(6) Never use an impact wrench to remove or install
temperature switches or temperature sensors.
(7) When checking continuity at the wire connector, in-
sert the tester probe carefully to prevent terminals
from bending.
(8) When using a vacuum gauge, never force the hose
onto a connector that is too large. Use a step±down
adapter for adjustment. Once the hose has been
stretched, it may leak air.

B04757
B04752
HV Fuse
IGCT Relay Engine Room J/B
Engine Room R/B No. 2
B04760
IN±18
± INTRODUCTIONFOR ALL OF VEHICLES
18 Author: Date:
2001 PRIUS (RM778U)

Remove the service plug with the insulated
gloves on.
If the service plug cannot be removed due to damage to the rear
portion of the vehicle, remove the HV fuse or IGCT relay
instead.
(c) Moving the damaged vehicle
HINT:
If any of the following applies, tow the vehicle away using a tow
truck lorry.

One or more of the high±voltage components and cables
is damaged.

The driving, traction, or fuel system is damaged.

The READY light is not lit when you turn ignition key to the
ON position.
NOTICE:

Before towing the vehicle away using a break down
lorry, disconnect the cable from the negative (±) ter-
minal of the auxiliary battery and remove the service
plug.
Only if none of the above applies and you see no prob-
lems that might affect the driving operation, you are
allowed to drive the vehicle away from the place of ac-
cident.

Preform the procedure below if the READY light goes
off or you detect an abnormal noise, abnormal smell,
or strong vibration while traveling:
(1) Park the vehicle in a safe place.
(2) Move the shift lever to the P position and engage
the parking brake.
(3) Disconnect the cable from the negative (±) terminal
of the auxiliary battery.
(4) Remove the service plug with insulated gloves on.