TOYOTA PRIUS 2001 Service Repair Manual

± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±673
2001 PRIUS (RM778U) B1 ± Ground
(ROUT ± Body ground)
Ignition switch ON and shift lever position is ºRº
or except ºRºBelow 1V or 10 ± 14 V
B2 ± Ground
(MPX+ ± Body ground)Ignition switch ONPulse generation
B3 ± Ground
(MPX ± Body ground)Ignition switch ONPulse generation
B5 ± Ground
(ACC ± Body ground)Ignition switch ACC10 ± 14 V

DI7XS±01
DI±674
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
PROBLEM SYMPTOMS TABLE
TROUBLESHOOTING:
Flow chart No.SymptomSee page
1Check the communication between the combination meter and the multiplex com-
munication circuit.DI±671
2The whole meter does not functionDI±672
3The margin of error in speedometer is large. Or it remains as 0 mph.DI±673
4Fuel receiver gauge is inoperative or improper.DI±674
5Indicators or warning lights do not light up.DI±676
Fuel gauge:
SymptomSuspect AreaSee page
Displayed level is higher or lower than the actual level.1. Inclination sensor resetting
2. Body ECUBE±47
IN±41
General:
SymptomSuspect area
Meter display does not properly function.3. Combination meter ECU
Entirely black screen appears.1. Fuse
2. Wire harness and connector
3. Combination meter ECU
Turning the light control switch ON does not dim the light.1. Illumination switch
2. Wire harness and connector
3. Combination meter ECU
Brightness cannot be changed by the illumination switch operation.1. Illumination switch
2. Wire harness and connector
3. Combination meter ECU
Speedometer:
SymptomSuspect area
Improper display (Remained as 0 km/h)1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
Speedometer only does not light up.1. Combination meter ECU
Abnormal display (Incomplete numbers displayed)1. Combination meter ECU
DIsplayed value changes frequently or sharply.1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
Margin of error in speedometer is large.1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
ODO/TRIP Meter:
SymptomSuspect area
ODO/TRIP only does not light up.1. Combination meter ECU
Abnormal display (Incomplete number displayed)1. Combination meter ECU
Both meters do not integrate values. (When speedometer is normal)1. Combination meter ECU
Trip meter only does not integrate values.1. ODO/TRIP switch
2. Combination meter ECU

± 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

DI±682
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
4 Check the corresponding switch or ECU.
CHECK:
Check if the corresponding switch or ECU is normal or not.
Ye s
No Corresponding switch or ECU faulty.
Combination meter ECU faulty.
*:
Multiplex communication inputSingle Communication Input
OPEN DOOR WARNINGHI±BEAM INDICATOR
BRAKE WARNINGTURN SIGNAL IND
OUTPUT CONTROL INDICATORSRS WARNING
SHIFT POSITION INDICATORABS WARNING
SEAT BELT WARNINGCHECK ENGINE WARNING
READY INDICATOR
WATER TEMPERATURE WARNING
OIL PRESSURE WARNING
CRUISE CONTROL INDICATOR
TAIL INDICATOR
DISCHARGE WARNING

DI7NN±01
I15530
B9 B8
DI±686
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
TERMINALS OF ECU
BODY ECU
Symbols (Terminals No.)Wiring ColorConditionSTD Voltage (V)
FLD e E GBWBPower window (FR LH) is not operatingBelow 1 vFLD e E
(B8±2 ± B9±1)G - B e W ± BPower window (FR LH) is operating downward10 ± 14 v
FLU e E RWWBPower window (FR LH) is not operatingBelow 1 vFLU e E
(B8±3 ± B9±1)R ± W e W ± BPower window (FR LH) is operating upward10 ± 14 v
LUG e E LBWBLuggage compartment door key lock and unlock switch is ONBelow 1 vLUG e E
(B8±5 ± B9±1)L ± B e W-BLuggage compartment door key lock and unlock switch is OFF10 ± 14 v
RX (B8±6)YAVC ± LAN communication circuit±±
PRG (B8±7)B ± RWireless door lock ECU communication circuit±±
RDA (B8±8)LWireless door lock ECU communication circuit±±
HR e E BRWBHorn switch is ONBelow 1 vHR e E
(B8±10 - B9±1)B ± R e W- BHorn switch is OFF10 ± 14 v
BDR ± ± Body ground
(B8±11 - Body ground)W ± L e
Body groundConstant10 ± 14 v
PCTY e E RWWBPassenger door courtesy switch is OFFBelow 1 vPCTY e E
(B8±12 - B9±1)R ± W e W - BPassenger door courtesy switch is ON10 ± 14 v
HCTY e E RWWBEngine hood courtesy switch is OFFBelow 1 vHCTY e E
(B8±13 - B9±1)R ± W e W - BEngine hood courtesy switch is ON10 ± 14 v
LCTY e E RLWBLuggage door courtesy switch is OFFBelow 1 vLCTY e E
(B8±14 - B9±1)R ± L e W - BLuggage door courtesy switch is ON10 ± 14 v
MPX+ (B8±15)GR ± BMultiplex communication circuit±±
MPX± (B8±16)GRMultiplex communication circuit±±
LSWP e E WWBPassenger door unlock detection switch OFF (door unlocked)Below 1 vLSWP e E
(B8±17 - B9±1)W e W - BPassenger door unlock detection switch ON (door locked)10 ± 14 v
LSR e E WLWBRear door unlock detection switch OFF (door unlocked)Below 1 vLSR e E
(B8±18 - B9±1)W ± L e W - BRear door unlock detection switch ON (door locked)10 ± 14 v
SH e E BWWBTheft deterrent system is not operatingBelow 1 vSH e E
(B8±20 - B9±1)B ± W e W - BTheft deterrent system is operating10 ± 14 v
E ± Body ground
(B9±1 - Body ground)W ± B e
Body groundConstantBelow 1 v

± 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

DI6QW±04
I15489
Body ECU
B B9
B8
1 5
8 11
159
8
8
2
13 5 3 1
6
24
1 1BDR F
FJ27
J/C
W±B
W±B
B±GB±Y
W±G W±GWR±G
2C
2D
2K 2B2H
2D10A GAUGE IG1 Relay30A DOOR7.5A ECU±B
5A AM1
J11
J/C
ID Battery F13 F11100A DC/DC FL Block No. 1I15 Ignition Switch
AM1 IG1
F18
FL Block No. 2
120A MAINB9 E Instrument Panel J/B
B
IG
A 7.5A OBDII
9
2DR±G
D
D
J26
J/CW±L W±L
W DI±690
± DIAGNOSTICSBODY CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT INSPECTION
Power Source Circuit
CIRCUIT DESCRIPTION
This circuit provides power to operate the Body ECU.
WIRING DIAGRAM