2001 TOYOTA PRIUS light

± DIAGNOSTICSBODY CONTROL SYSTEM
DI±697
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check taillight relay (See page DI±691).
NG Replace the taillight relay.
OK
2 Check wireharness and connector between taillight relay and body ECU, battery
and taillight relay (See page IN±41).
NG Repair or replace wireharness or connector.
OK
Proceed to next circuit inspection shown on
problem symptoms table (See page
DI±683).

I15484
2 3 66
8 7
1 4 2
1
4
3 2 1 1
11
1
710
883
A L D
FE
E
E
LE
ER±L
R±G
R±W
R±G R±W R±W R±W
R±G
R±G B±G
R±G B
F13 F12
2I
2A 1B1F
1F
1F3
ID2 IA2J20
J/C
IA1
J4J5
ID 2K 2A
15
17
BatteryC10 High Beam
Indicator Light
(Comb. meter) F18
FL Block No. 2
J11
J/CJ4 H2
Headlight RH
10A HEAD (LH) 10A HEAD (RH)
Short Pin HEAD RelayEngine Room J/BB9
Body ECU
Short Pin
120A MAIN
Instrument
Panel J/BJ12 J13
W±B
H1
Headlight
LH
1
FL Block No. 13
1
HRLY
Instrument
Panel J/B DI±698
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
Headlight Relay Circuit
CIRCUIT DESCRIPTION
Head light relay will be ºONº by operating the headlight switch. The transistor which activates the headlight
relay has two sorts: one activates directly by the headlight switch for fail safe and the other activates by CPU.
the one that activates by CPU has two systems and prevents the headlight from turning off at the time of
one system trouble in the automatic operation circuit.
When the theft deterrent system is activated, it causes the transistor in the ECU to switch ON and OFF at
approximately 0.25 sec. intervals. This switches the headlight control relay ON and OFF, thus flashing the
headlights (See the wiring diagram below).
In this condition, if any of the following operations is done, the transistor in the ECU goes OFF and the head-
light control relay switches OFF, thus stopping the headlights flashing:
(1) Unlock the front LH or RH door with a key.
(2) Turn the ignition switch to ACC or ON position.
(3) Unlock the doors with the wireless door lock control system.
(4) Wait for approximately 60 seconds.
WIRING DIAGRAM
DI5VQ±04

± DIAGNOSTICSBODY CONTROL SYSTEM
DI±699
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check headlight relay (See page DI±693).
NG Replace the headlight relay.
OK
2 Check wireharness and connector between headlight relay and body ECU, bat-
tery and headlight relay (See page IN±41).
NG Repair or replace wireharness or connector.
OK
Proceed to next circuit inspection shown on
problem symptoms table (See page
DI±683).

I15508
Body ECU
Engine Room J/B
Instrument Panel J/B
F18 Fusible Link Block No.2
J/C
120A MAIN FL
Battery L6
Luggage
Compartment
Light SW L5
Luggage
Compartment
LightI16 Interior Light
P4 Front Personal Light7
22N1
R±B 1 2
L±Y J29E
J30DJ/C
L±Y
W±B
L±Y
L±Y
2M3
2G2
L±Y1J 715A DOME
1B2
B
W±B B BJ/C
BI 11 J30D
J29E
1
F131
F12Instrument Panel J/B
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±707
2001 PRIUS (RM778U)
Illumination circuit
CIRCUIT DESCRIPTION
Receiving the courtesy signal from either of the door ECU, the Body ECU will make the interior light, ignition
light, and foot light come on.
WIRING DIAGRAM
DI6LX±03

DI±708
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check illumination light (Interior light system)(See page BE±27).
NG Replace the failure light.
OK
2 Check wireharness and connector between each illumination light and Body
ECU, battery and each illumination light (See page IN±41).
NG Repair or replace wireharness or connector.
OK
Proceed to next circuit inspection shown on
problem symptoms table
(See page DI±683).

I15496
613Body ECU
A
B9
IND C7
Center Cluster SW
(Center Cluster Module Control)
LG±BLG±B J27
J/C
A
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±709
2001 PRIUS (RM778U)
Indicator Light Circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is preparing to set, this circuit lights up the indicator light. When the system
has been set, it continuously turns the indicator light on for 0.2 secs. and turns it off for 1.8 secs., thus blinking
the indicator light.
WIRING DIAGRAM
DI7NY±01

DI±710
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check indicator light. (center cluster module control)
NG Replace center cluster module control.
OK
2 Check harness and connector between body ECU and indicator light, indicator
light and body ground (See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace body ECU.*1
*1: When there is a malfunction that the theft deterrent system
cannot be set, proceed to the next numbered circuit inspection
shown on problem symptom table (See page DI±683).

I15488
5
8
1
2
11
8
8 A
E DA
AA
AB9
DBKL
IJ1
J22
J23 IJ1J24 J24
2D 2K
IDJ11
J/CG±O
W±B
W±B W±BW±B
W±B W±BG±O
G±O B20
Buckle SW LH
Instrument Panel J/BJ29
J/CBody ECU
J/C
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±721
2001 PRIUS (RM778U)
Driver Buckle Switch Circuit
CIRCUIT DESCRIPTION
When the buckle switch of the driver's seat is ON with the ignition switch ON, the body ECU sends a signal
to make the seat belt warning light for the driver's seat light up and to sound a buzzer.
When the buckle switch of the passenger seat is ON and the passenger seat belt occupant detecting sensor
is ON with the ignition switch ON, the body ECU sends a signal to make the seat belt warning light for the
passenger seat light up.
WIRING DIAGRAM
DI6R2±04