2001 TOYOTA PRIUS warning lights

H15525
Combination Meter
Instrument Panel J/B
10A ACC
ACC Relay
5A AM1
W±G L15
C10
16
C10
5
C11
GR±RGR±R
W±BB±Y 9
2A
2
2D
8
2A
1
2H
8
2C
3
2B53
128
2K4
2B 1
2E3
A18LA
1
F11C
J27
Fl Block No. 1
23P±LW 1
F13
1 B±GL
GR±R
BBC
J28AB
A
J11
J/C
Battery F18
FL
Block
No. 2DLC3
DC/DC100A
J/C
I15 Ignition S/W
120A
MAINAirbag Sensor
Assembly
B±Y6
ID J26
J/C
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±637
2001 PRIUS (RM778U)
SRS Warning Light Circuit Malfunction
CIRCUIT DESCRIPTION
The SRS warning light is located on the combination meter.
When the SRS is normal, the SRS warning light lights up for approx. 6 seconds after the ignition switch is
turned from the LOCK position to ON position, and then turns off automatically.
If there is a malfunction in the SRS, the SRS warning light lights up to inform the driver of the abnormality.
When terminals Tc and CG of the DLC3 are connected, the DTC is displayed by blinking the SRS warning
light.
WIRING DIAGRAM
DI7QT±01

AB0117H01293H01295
Airbag Sensor Assembly
LOCK
DI±638
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
Always lights up, when ignition switch is in LOCK position
1 Prepare for inspection (See step 1 on page DI±629).
2 Does SRS warning light turn off?
PREPARATION:
(a) Turn the ignition switch to LOCK.
(b) Disconnect negative (±) terminal cable from the battery,
and wait at least for 90 seconds.
(c) Disconnect the airbag sensor assembly connector.
(d) Connect negative (±) terminal cable to the battery.
CHECK:
Check operation of SRS warning light.
NO Check SRS warning light circuit or terminal A/B
circuit of DLC3.
YES
Replace airbag sensor assembly.

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

± BRAKETROUBLESHOOTING
BR±3
1518 Author: Date:
2001 PRIUS (RM778U) Noise from brakes
1. Pad or lining (Cracked or distorted)
2. Installation bolt (Loose)
3. Disc or drum (Scored)
4. Pad support plate (Loose)
5. Sliding pin (Worn)
6. Pad or lining (Dirty)
7. Pad or lining (Glazed)
8. Tension or return spring (Faulty)
9. Anti±squeal shim (Damaged)
10.Shoe hold±down spring (Damaged)BR±23
BR±32
BR±26
BR±26
BR±32
BR±23
BR±26
BR±23
BR±32
BR±23
BR±32
BR±32
BR±23
BR±32
Brake warning light lights up*1
(Parking brake pedal released)
1. Brake fluid level
2. Hydraulic brake booster power supply system (Faulty)
BR±41
Brake warning light lights up and brake warning buzzer sounds*2Hydraulic brake booster power supply system (Faulty)BR±41
ABS warning light lights up*31. Anti±lock brake system (Faulty)
2. Hydraulic brake booster power supply system (Faulty)
BR±41
*1, *3: The light may stay on for about 60 seconds after the engine has been started. It is normal if it goes
out after a while.
*
2, *3: Depressing the brake pedal repeatedly may turn on the warning light and buzzer. It is normal if the
light goes out and the buzzer stops sounding after a few seconds.

BE±4
± BODY ELECTRICALTROUBLESHOOTING
1671 Author: Date:
2001 PRIUS (RM778U) Headlight flickers.
1. Bulb
2. Wire Harness±
±
Headlight is dark.1. Bulb
2. Wire Harness±
±
Taillight does not come on with light control switch in TAIL.1. Taillight Control Relay
2. Wire HarnessBE±20
±
Taillight does not go out with light control switch in OFF.1. Taillight Control Relay
2. Wire HarnessBE±20
±
Headlight does not come on with engine running and light control
switch in OFF.
1. ECU±B Fuse
2. GAUGE Fuse
3. Daytime Running Light Main Relay
4. Daytime Running Light Relay
5. Alternator L Terminal
6. Body ECU
7. Parking Brake Switch
8. Wire HarnessBE±12
BE±12
BE±20
BE±20
±
DI±678
BE±42
±
TURN SIGNAL AND HAZARD WARNING SYSTEM
SymptomSuspect AreaSee page
ºHazardº and ºTurnº do not light up.
1. GAUGE Fuse
2. TURN HAZ Fuse
3. Ignition Switch
4. Turn Signal Flasher Relay
5. Wire HarnessBE±12
BE±12
BE±17
BE±25
±
Hazard warning light does not light up.
(Turn is normal)1. Hazard Warning Switch
2. Wire HarnessBE±25
±
Turn signal does not light up.
(Hazard is normal)1. Turn Signal Switch
2. Wire HarnessBE±25
±
Turn signal does not light up in one direction.1. Turn Signal Switch
2. Wire HarnessBE±25
±
Only one bulb does not light up.1. Bulb
2. Wire Harness±
±
INTERIOR LIGHT SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
SymptomSuspect AreaSee page
All the lights do not come ON.DOME FuseBE±12
The driver door courtesy light does not come ON when the
driver's door is opened.1. Driver's Door Courtesy Switch
2. Wire Harness
3. Body ECUBE±27
±
±
The passenger door courtesy light does not come ON when the
passenger's door is opened.1. Passenger's Door Courtesy Switch
2. Wire Harness
3. Body ECUBE±27
±
DI±678
The room light does not come on when the rear±right door is
opened.
1. Rear±Right Door Courtesy Switch
2. Wire Harness
3. Body ECU
4. Room LightBE±27
±
DI±678
±
The room light does not come on when the rear±left door is
opened.
1. Rear±Left Door Courtesy Switch
2. Wire Harness
3. Body ECU
4. Room LightBE±27
±
DI±678
±
Only one of the bulbs comes ON.Bulb±

± BODY ELECTRICALTROUBLESHOOTING
BE±7
1674 Author: Date:
2001 PRIUS (RM778U)
Warning Lights:
COMBINATION METER
SymptomSuspect AreaSee page
Warning light do not light up. (Except Discharge, Open Door and
SRS)
1. GAUGE Fuse
2. Meter Circuit Plate
3. DC/DC converter
4. Wire Harness±
BE±39
±
±
Fuel Level warning light does not light up.
1. Bulb
2. Meter Circuit Plate
3. Fuel Tank Assembly
4. Wire Harness±
BE±39
±
±
Low Oil Pressure warning light does not light up.
1. Bulb
2. Low Oil Pressure Warning Switch
3. Meter Circuit Plate
4. Wire Harness±
BE±42
BE±39
±
ABS warning light does not light up.
1. Bulb
2. ABS ECU
3. Wire Harness±
DI±351
±
Seat Belt warning light does not light up.
1. Bulb
2. Buckle Switch
3. Meter Circuit
4. Wire Harness±
BE±42
BE±42
±
Brake warning light does not light up.
1. Bulb
2. Parking Brake Switch
3. Brake Fluid Level Warning Switch
4. Meter Circuit Plate
5. Wire Harness±
BE±42
BE±42
BE±39
±
SRS Warning light does not light up.
1. Bulb
2. Airbag Sensor Assembly
3. Meter Circuit Plate
4. Wire Harness±
DI±495
BE±39
±
Open Door warning light does not light up.
1. DOME Fuse
2. Bulb
3. Door Courtesy Switch
4. Meter Circuit Plate
5. Wire Harness±
±
BE±27
BE±39
±
Indicator Lights:
COMBINATION METER
SymptomSuspect AreaSee page
High beam indicator light does not light up.
1. Bulb
2. Meter Circuit Plate
3. Wire Harness
4. Headlight System±
BE±39
±
BE±20
Turn indicator light does not light up.
1. Bulb
2. Meter Circuit Plate
3. Wire Harness
4. Turn Signal and Hazard Warning System±
BE±39
±
BE±25
Malfunction indicator light does not light up.
1. Bulb
2. ECM
3. Meter Circuit Plate
4. Wire Harness±
±
BE±39
±
Indicator lights do not light up. (Except Turn, Hi±beam and
security)1. GAUGE Fuse
2. Wire Harness±
±