2001 TOYOTA PRIUS light

± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±675
2001 PRIUS (RM778U) Trip meter cannot be reset.
1. ODO/TRIP switch
2. Combination meter ECU
Display cannot be shifted among ODO, TRIPA and TRIPB.1. ODO/TRIP switch
2. Combination meter ECU
Without resetting, the display returns to 0.0 km.1. ODO/TRIP switch
2. +B wire harness
3. Combination meter ECU
Error of accumulated distance is large.1. Accessory that utilizes vehicle speed signals.
2. GND wire harness
3. Brake ECU
4. Wire harness and connector
5. Combination meter ECU
Others:
SymptomSuspect area
Some indicators or warning lights are always ON.1. Meter circuit plate
2. Corresponding switch and ECU
3. Combination meter ECU
4. Multiplex communication circuit
Some indicators or warning lights do not light up.1. Bulb
2. Meter circuit plate
3. Corresponding switch and ECU
4. Combination meter ECU
5. Multiplex communication circuit
Buzzer does not stop.1. Combination meter ECU
2. Corresponding switch and ECU

± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±681
2001 PRIUS (RM778U)
5. Indicators or warning lights do not light up. (*multiplex communication circuit input
indicator or warning)
INSPECTION PROCEDURE
1 Multiplex communication circuit input indicator or warning.
2 Communication check.
CHECK:
Check if the communication between the combination meter and the multiplex communication circuit is nor-
mal or not.
Ye s
No Communication error. Wire harness faulty.
3 Check the bulb or circuit plate.
CHECK:
Check if the bulb circuit plate is normal or not. Check open or short circuit in wire harness.
Ye s
No Bulb or circuit plate faulty.
DI7XX±01

± DIAGNOSTICSBODY CONTROL SYSTEM
DI±687
2001 PRIUS (RM778U)Symbols (Terminals No.)
Wiring ColorConditionSTD Voltage (V)
HRLY e E RWWBLight control switch OFFBelow 1 vHRLY e E
(B9±2 - B9±1)R ± W e W - BLight control switch TAIL or HEAD10 ± 14 v
PKBL e E PLWBPassenger side buckle switch ON (belt fastened)Below 1 vPKBL e E
(B9±3 - B9±1)P ± L e W - BPassenger side buckle switch OFF (belt fastened)10 ± 14 v
DKBL e E GOWBDriver side buckle switch ON (belt fastened)Below 1 vDKBL e E
(B9±5 - B9±1)G ± O e W - BDriver side buckle switch OFF (belt fastened)10 ± 14 v
L2 e E GWBDoor lock manual switch OFF or UNLOCKBelow 1 vL2 e E
(B9±7 - B9±1)G e W - BDoor lock manual switch LOCK10 ± 14 v
B e Body ground
(B9±±9 - Body ground)R ± G e
Body groundConstant10 ± 14 v
ACTD e E
(B9±10 - B9±1)R e W - BDriver door is operating10 ± 14 v
TRLY e E LGWBLight control switch OFFBelow 1 vTRLY e E
(B9±11 - B9±1)LG e W - BLight control switch TAIL or HEAD10 ± 14 v
IND e E
(B9±13 - B9±1)LG ± B e
W - BDuring set is theft deterrent system10 ± 14 v
L1 e E GBWBDoor key lock and unlock switch OFF or UNLOCKBelow 1 vL1 e E
(B9±14 - B9±1)G ± B e W - BDoor key lock and unlock switch LOCK10 ± 14 v
UL1 e E RBWBDoor key lock and unlock switch OFF or LOCKBelow 1 vUL1 e E
(B9±15 - B9±1)R ± B e W - BDoor key lock and unlock switch UNLOCK10 ± 14 v
UL2 e E LBWBDoor lock manual switch OFF or LOCKBelow 1 vUL2 e E
(B9±16 - B9±1)L ± B e W - BDoor lock manual switch UNLOCK10 ± 14 v
H e E RWBLight control switch OFF or TAILBelow 1 vH e E
(B9±17 - B9±1)R e W - BLight control switch HEAD10 ± 14 v
T e E LG BWBLight control switch OFFBelow 1 vT e E
(B9±18 - B9±1)LG ±B e W ± BLight control switch TAIL or HEAD10 ± 14 v

DI62G±07
DI±688
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
PROBLEM SYMPTOMS TABLE
POWER WINDOW CONTROL SYSTEM
SymptomSuspect AreaSee page
All the power windows does not operate.
3. Master switch circuit
4. Driver door ECU with master switch
5. Body ECUDI±724
DI±730
IN±41
Power window does not operate.1. Power window switch circuit
2. Body ECUDI±726
IN±41
DOOR LOCK CONTROL
SymptomSuspect AreaSee page
Lock or unlock cannot be operated with door lock control S/W.
1. Door lock control switch circuit
(Master switch)
2. Body ECUDI±706
DI±724
IN±41
Door key linked function does not operate.1. Door key lock and unlock switch circuit
2. Body ECUDI±708
IN±41
Key confinement prevention function does not operate.1. Key unlock switch circuit
2. Body ECUDI±695
IN±41
Does not lock and unlock each door only.1. Door lock motor circuit
2. Body ECUDI±712
IN±41
Luggage compartment door opener function does not operate.1. Luggage component door courtesy switch circuit
2. Body ECUDI±722
IN±41
WIRELESS DOOR LOCK CONTROL
SymptomSuspect AreaSee page
All function of wireless door lock control system do not operate.
1. Transmitter
2. Wireless tuner circuit
3. Key unlock warning switch circuit
4. Body ECUBE±83
DI±728
DI±695
IN±41
Lock (or unlock) function does not operate.
1. Door key lock and unlock switch circuit
2. Door unlock detection switch circuit
3. Body ECUDI±708
DI±710
IN±41
Automatic lock function operates even if any door is opened within
30 seconds after all doors are unlocked by wireless door lock
control system .1. Door courtesy switch circuit
2. Body ECUDI±714
IN±41
ILLUMINATED ENTRY
SymptomSuspect AreaSee page
Illuminated entry does not operate.
1. Driver door courtesy switch circuit
2. Illuminaction circuit
3. Body ECUDI±714
DI±702
IN±41
HEADLIGHT AND TAILLIGHT SYSTEM:
SymptomSuspect AreaSee page
Headlight does not light up.
1. Light control switch circuit
2. Headlight control relay circuit
3. Body ECUDI±689
DI±693
IN±41
Taillight does not light up.
1. Light control switch circuit
2. Taillight control relay circuit
3. Body ECUDI±689
DI±691
IN±41
Auto turn±off system does not operate.1. Driver door courtesy switch circuit
2. Body ECUDI±714
IN±41

± DIAGNOSTICSBODY CONTROL SYSTEM
DI±689
2001 PRIUS (RM778U)
OTHERS
SymptomSuspect AreaSee page
Does not turn off the driver seat belt warning light1. Driver buckle switch circuit
2. Body ECUDI±716
IN±41
Does not turn off the passenger seat belt warning light.1. Passenger buckle switch circuit
2. Body ECUDI±718
IN±41
Theft deterrent indicator light does not blink when system is set.1. Indicator light circuit
2. Body ECUDI±704
IN±41
Body ECU does not operate.
1. Power source circuit
2. Body ECUDI±685
IN±41

I15486
OFF
TAIL
HEAD
LOWTHELB9
BODY ECU
Light
Control
SW
Dimmer
SWHIGH
FLASHH 17 LG±R ID2
135
W±B A J17
J/C
IG16 C13
Combination SWT 18
R 6
ID2
R LG±R
14
HF HU HL DI±694
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
Light Control Switch Circuit
CIRCUIT DESCRIPTION
This circuit defects the state of the light control switch.
WIRING DIAGRAM
DI5VO±07

± DIAGNOSTICSBODY CONTROL SYSTEM
DI±695
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check light control switch (See page DI±689).
NG Replace the headlight control switch.
OK
2 Check wireharness and connector between headlight control switch and body
ECU (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).

I15485
BatteryB9
BODY ECU
11
F112 5
6 3
2 15
1
11
1 WID2 2F
2K 2HTAIL
RELAY7.5A
TAIL Instrument Panel J/Bto Taillight
F18
FL BLock No. 2 FL Block No. 1LG LG
F13B±GTRLY
100A DC/DC 120A MAIN DI±696
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
Taillight Relay Circuit
CIRCUIT DESCRIPTION
Taillight relay will be ºONº by operating the taillight switch. The transistor which activates the tail light relay
has two sorts: one activates by the tail light switch for fail safe and the other activates by CPU.
When the theft deterrent system is activated, it causes the transistor in the ECU to switch ON and OFF at
approximately 0.4 sec. intervals. This switches the taillight control relay ON and OFF, thus flashing the tail-
lights (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 taillight
control relay switches OFF, thus stopping the taillights 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
DI6QY±04