2001 TOYOTA PRIUS O2 sensor

N14677
Fuse
AB0119H01300
H01301
Airbag Sensor Assembly
ON
LA
(+)
(±)
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±639
2001 PRIUS (RM778U)
Does not light up, when ignition switch is turned to ON
1 Check AM2 Fuse.
PREPARATION:
Remove the AM2 fuse.
CHECK:
Check continuity of the AM2 fuse.
OK:
Continuity
HINT:

Fuse may be burnt out even if it appears to be OK during
visual inspection.

If fuse is OK, install it.
NG Go to step 4.
OK
2 Prepare for inspection (See step 1 on page DI±629).
3 Check SRS warning light circuit.
PREPARATION:
(a) Disconnect the airbag sensor assembly connector.
(b) Connect negative (±) terminal cable to the battery.
(c) Turn the ignition switch to ON.
CHECK:
Measure the voltage between body ground and LA terminal of
the harness side connector of the airbag sensor assembly.
OK:
Voltage: 10 ± 14 V
NG Check combination meter or repair SRS warn-
ing light circuit.
OK
Replace airbag sensor assembly.

H15526
J11
J/C AW±B 2KW±BJ24
J/C
W±BDLC3
P±BJ26
J/C
P±B
Tc
8 2D 8AA
413 CGTc
E
E19
A18
Instrument Panel J/BAirbag Sensor
Assembly
ID
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±641
2001 PRIUS (RM778U)
Tc Terminal Circuit
CIRCUIT DESCRIPTION
By connecting terminals Tc and CG of the DLC3 the airbag sensor assembly is set in the DTC output mode.
The DTCs are displayed by blinking the SRS warning light.
WIRING DIAGRAM
DI6Q0±06

AB0119H10689H10656
ON
Tc
(+) (±)
AB0117 AB0119H01302H12918
LOCK
ON
Airbag Sensor Assembly
Tc
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±643
2001 PRIUS (RM778U)
3 Check voltage between terminal Tc of DLC3 and body ground.
CHECK:
Measure the voltage between terminal Tc of DLC3 and body
ground.
OK:
Voltage: 10 ± 14 V
OK Check harness between terminal E1 of DLC3
and body ground.
NG
4 Check airbag sensor assembly.
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) Insert service wire into terminal Tc from back side as
shown in the illustration.
(e) Connect the airbag sensor assembly connector with ser-
vice wire.
(f) Connect negative (±) terminal cable to the battery.
(g) Turn the ignition switch to ON and wait at least for 20 se-
conds.
(h) Connect service wire of terminal Tc to body ground.
CHECK:
Check operation of the SRS warning light.
OK:
SRS waning light comes on.
NOTICE:
Pay due attention to the terminal connecting position to
avoid a malfunction.
OK Check harness between the airbag sensor as-
sembly and DLC3.
NG
Replace airbag sensor assembly.

AB0119H01304H01305
LOCKAirbag Sensor Assembly
Tc
(+)
(±)
DI±644
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
2001 PRIUS (RM778U)
If the DTC is displayed without a DTC check procedure, perform the following
troubleshooting.
1 Check resistance between terminal Tc of airbag sensor assembly and body
ground.
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.
CHECK:
Check resistance between terminal Tc of the airbag sensor as-
sembly connector and body ground.
OK:
Resistance: 1 MW or Higher
NG Repair or replace harness or connector.
OK
Replace airbag sensor assembly.

Flashing pattern No.1
Flashing pattern No.2
0.6 sec. 0.6 sec.
0.3 sec. 0.3 sec. 1.2 sec. ON
OFF ON
OFF
0.3 sec.
DI±670
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
2. FUEL GAUGE DIAGNOSIS CHECK
(a) Fuel emergency display
HINT:
If FR voltage input to the fuel sender gauge is abnormal (4.8 V or more, or 0.06 V or less) due to any error,
an emergency will be displayed.
(b) Display:
Immediately after the ignition switch is ON, all of the segments flash.
Diagnosis displayTrouble ItemPlausible Cause
All segments flashing
(Flashing pattern No. 1)
Cycle: 1.2 sec
Duty: 50 %Multiple communication errorCommunication is cut off.
4. Body ECU faulty
5. Engine ECU faulty
6. Open or short in wire harness for communica-
tion
HINT:
Referring to the attached reference material 1 or
2, specify the main cause
All segments flashing
(Flashing pattern No. 2)
(300 msec. ON, 300 msec OFF) x 2 + 1.2
sec. OFFSender gauge related trouble1. Sender gauge faulty
2. Open or short in wire harness
Display segments and ºEº flashing.
(Flashing pattern No. 1)
Cycle: 1.2 sec
Duty: 50 %Temperature sensor (located in the tank) related
trouble1. Temperature sensor faulty
2. Open or short in wire harness
Display segments and ºEº flashing.
(Flashing pattern No. 2)
(300 msec. ON, 300 msec. OFF) x 2 + 1.2
sec. OFFIndication sensor (located in the meter ) trouble1. Combination meter faulty
Segment No. 1 flashing
(Flashing pattern No. 1)
Cycle: 1.2 sec
Duty: 50 %This does not mean any failure.
When a battery is connected, it continues flash-
ing until the volume is confirmed.This occurs when the battery is turned ON.
HINT:
Low fuel warning: Cycle: 0.6 sec.;
Duty: 50 %

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

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

I15487
Body ECU
PBKL 3
9
3
1
10
88B9 IJ1
J24
J25 IJ1
2K2DW±B W±BW±BW±BP±L
P±L
W±B
J11
J/C
IDAAA
Instrument
Panel J/B B21
Buckle SW RH and
Seat Belt Warning
Occupant Detection SW
J/C
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±723
2001 PRIUS (RM778U)
Passenger buckle switch and seat belt warning occupant detec-
tion sensor
CIRCUIT DESCRIPTION
This circuit detects the conditions of the passenger buckle switch and the seat belt warning occupant detec-
tion sensor, and makes the passenger seat belt warning flash.
WIRING DIAGRAM
DI7NR±01