2001 TOYOTA PRIUS bulb

BODY ELECTRICAL ± LIGHTING
151LBE68151LBE67
Multi-Reflector Type HeadlightConventional Headlight Reflector
(Multiple Parabolic Shape)
Headlight Bulb
Headlight Bulb
Lens
Light DistributionReflector
(Rotating Parabolic Shape)
Headlight Bulb
Lens Cut
Lens
Light Distribution
182BE03
From
BatteryDimmer Relay
Headlight
Relay
Parking
Brake Switch
H-LP DIM
PKBDaytime
Running
Light Relay
DRL
From
BatteryEH
HILO HI
LO
No.4
Daytime
Running
Light Relay
144
LIGHTING
HEADLIGHTS
The prius has newly adopted the multi-reflector headlights. Conventional headlights accomplish the dispersion
and distribution of the light that is emitted by the bulbs through the lens cut pattern. However, with the multi-reflec-
tor type headlights, the light from the bulbs is dispersed and distributed through multiple parabolic shaped reflec-
tors. As a result, the lens cut pattern is no longer provided in the center of the lens, thus realizing a clear look.

Light Distribution Diagram 
DAYTIME RUNNING LIGHT SYSTEM
The daytime running light system is adopted for Canada model as standard and U.S.A. model as optional
equipment. This system is designed to automatically activate the headlights (dimmed low beams) during the
daytime to keep the car highly visible to other vehicles.
This system is controlled by a semi-conductor relay circuit (daytime running light relay).

PP26E±02
PP±50
± PREPARATIONBODY ELECTRICAL
2001 PRIUS (RM778U)
EQUIPMENT
Voltmeter
Ammeter
Ohmmeter
Test lead
SyphonBrake fluid level warning switch
Bulb (3.4W)Fuel sender gauge, Fuel level warning switch
Dry cell batteryWireless door lock transmitter
Torque wrench
Masking tapeRear window defogger wire
Tin foilRear window defogger wire

DI6UT±02
DI±14
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instru-
ment or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for that code
listed in the table below. For details of each code, turn to the page referred to under the ''See page
'' for the respective ''DTC No.'' in the DTC chart.
When the ignition switch is ON and ºREADYº indicator light is OFF, the bulb check of the ºMILº is per-
formed (ºMILº is ON).
When ºMILº is ON, but the DTC of the engine is not memorized, it may be because of HV control system
abnormality, so check HV control system beforehand.
SAE CONTROLLED:
DTC No.Detection ItemTrouble AreaMIL*1Memory
P0100
(DI±23)Mass Air Flow Circuit Malfunc-
tionOpen or short in mass air flow meter circuit
Mass air flow meter
ECM

P0101
(DI±27)Mass Air Flow Circuit Range/
Performance ProblemMass air flow meter
P0110
(DI±28)Intake Air Temp. Circuit Malfunc-
tionOpen or short in intake air temp. sensor circuit
Intake air temp. sensor (built into mass air flow meter)
ECM

P0115
(DI±32)Engine Coolant Temp. Circuit
MalfunctionOpen or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM

P0116
(DI±36)Engine Coolant Temp. Circuit
Range/Performance ProblemCooling system
Engine coolant temp. sensor
P0120
(DI±38)Throttle/Pedal Position Sensor/
Switch ºAº Circuit MalfunctionOpen or short in throttle position sensor circuit
Throttle position sensor
ECM

P0121
(DI±43)Throttle/Pedal Position Sensor/
Switch ºAº Circuit Range/Perfor-
mance ProblemThrottle position sensor
ECM
P0125
(DI±44)Insufficient Coolant Temp. for
Closed Loop Fuel Control
Open or short in heated oxygen sensor (bank 1 sensor 1)
circuit
Heated oxygen sensor (bank 1 sensor 1)
Air induction system
Fuel pressure
Injector
Gas leakage on exhaust system
ECM

P0128
(DI±49)Thermostat Malfunction
Thermostat
Cooling system
Water temperature
ECM

P0130
(DI±50)Heated Oxygen Sensor Circuit
Malfunction (Bank 1 Sensor 1)
(Except Calif.)
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
Air induction system
EGR system
Fuel pressure
Injector
ECM


A14037
Combination MeterECM
Instrument Panel J/B
W
BatteryE10 IG1 Relay
6
J11
J/C IG1C11
C10
ID DC/DCG±R
2A
A 5
W
W±B
F114
3GAUGE
Ignition SW 22
2 3B±Y
21
2 1
1 1
MAINL
AM1
B±G4
FL Block No. 1FL Block No. 2 F1312D
2B 2K 2H
86 5
AM1
W±G
MIL
DI±166
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
MIL Circuit Malfunction
CIRCUIT DESCRIPTION
If the ECM detects trouble, the MIL lights up. At this time, the ECM records a DTC in memory.
HINT:
When the ignition switch is ON and ºREADYº indicator light is OFF, the bulb check of the ºMILº is performed
(ºMILº is ON).
When ºMILº is ON, but the DTC of the engine is not memorized, it may be because of HV control system
abnormality, so check HV control system beforehand.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Troubleshoot in accordance with the chart below for each trouble symptom.
MIL does not light up
Start inspection from step 1 in case of using TOYOTA hand±held
tester and start from step 2 in case of not using TOYOTA hand±
held tester
MIL remains on
After inspection of step 3, start inspection from step 4 in case of
using TOYOTA hand±held tester and start from step 5 in case of
not using TOYOTA hand±held tester
DI6MN±03

± DIAGNOSTICSENGINE
DI±167
2001 PRIUS (RM778U)
1 Inspect diagnosis (normal mode, check mode) (See page DI±3).
OK Check and replace ECM (See page IN±41).
NG
2 Check MIL.
See combination meter troubleshooting on page BE±2.
NG Repair or replace bulb or combination meter as-
sembly.
OK
3 Check that ECM connectors are securely connected to ECM.
NO Connect connector to ECM.
YES
Check for open circuit in harness and connector between combination meter and ECM (See
page IN±41).
4 Check operation of MIL (See step 1).
OK Check and replace ECM (See page IN±41).
NG

A14089
B12009
F12396
DLC3
TOYOTA Hand±held Tester
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±179
2001 PRIUS (RM778U)
(b) Check the master warning light.
(1) Turn the ignition switch ON and confirm that the
master warning light comes on.
HINT:
If the master warning light does not come on, suspect a burnt
fuse, burnt bulb, or open in wiring harness.
(2) When the ºREADYº light is ON, the master warning
light should go off.
If the lamp remains on, the diagnosis system has detected a
malfunction in the system or the meassage such as ºWhen you
park your care, make sure you shift to Park P.º and ºThe batter-
ies will not charge if the shifter is Nº appears on the multi±in-
formation display.
Since DTC may be stored even though the lamp is OFF, be sure
to check DTC.
(c) Check the DTC.
(1) Prepare a TOYOTA hand±held tester.
(2) Connect the TOYOTA hand±held tester to the
DLC3.
(3) Turn the ignition switch ON and push the TOYOTA
hand±held tester main switch ON.
(4) Use the TOYOTA hand±held tester to check the
DTC, information code and freeze frame data and
note them down. (For operating instructions, see
the TOYOTA hand±held tester operator's manual).
HINT:

For one DTC, the HV diagnosis system can memorize
more than one information code and freeze frame data
corresponding to them. Therefore, when troubleshooting,
check all of the information codes, record the freeze
frame data and then start inspection according to the pro-
cedures of ºCircuit Inspectionº.

The HV ECU is communicating with each ECU of the en-
gine brake, HV battery and EMPS. So, if a warning is out-
put from the HV control system, check and record DTCs
of all ECUs. (See tables on the following pages.)
(5) See a related page to confirm details of the DTC.

A14089
B12009
F12396
DLC3
TOYOTA hand±held tester
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±317
2001 PRIUS (RM778U)
(2) Inspect the auxiliary battery, fuses, fusible links, wir-
ing harness, connectors and ground.
(b) Check the master warning light.
(1) Turn the ignition switch ON and confirm that the
master warning light comes on.
HINT:
If the master warning light does not come on, suspect a burnt
fuse, burnt bulb, or open in wiring harness.
(2) When the ºREADYº light is ON, the master warning
light should go off.
If the lamp remains on, the diagnosis system has detected a
malfunction or abnormality in the system.
(c) Check the DTC.
(1) Prepare a TOYOTA hand±held tester.
(2) Connect the TOYOTA hand±held tester to the
DLC3.
(3) Turn the ignition switch ON and push the TOYOTA
hand±held tester main switch ON.
(4) Use the TOYOTA hand±held tester to check the
DTC and freeze frame data and note them down.
(For operating instructions, see the TOYOTA hand±
held tester operator's manual).
Since the HV battery ECU stores DTC and freeze
frame data, when troubleshooting, check all of the
DTC, write down the freeze fame data and perform
inspection according to the procedures of ºCircuit
Inspectionº.
Because the HV battery ECU is communicating with
the HV ECU, if any DTC is stored in the HV battery
ECU, check and record DTC stored in the HV ECU
(For tables for DTC, see page DI±177).
(5) See a related page to confirm details of the DTC.

± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±443
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:
Troubleshoot in accordance with the chart below for each trouble symptom.
ABS warning light does not light up*1
ABS warning light remains on*2
*1: Start the inspection from step 1 in case of using the TOYOTA hand±held tester and start from step 2 in
case of not using TOYOTA hand±held tester.
*2: After inspection with step 4, start the inspection from step 5 in case of using the TOYOTA hand±held
tester and start from step 6 in case of not using TOYOTA hand±held tester.
1 Check operation of the brake warning light.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON, and push the TOYOTA hand±held tester main switch ON.
(c) Select the ACTIVE TEST mode on the TOYOTA hand±held tester.
CHECK:
Check that ºONº and ºOFFº of the ABS warning light can be shown on the combination meter on the TOYOTA
hand±held tester.
OK Check and replace brake ECU.
NG
2 Check ABS warning light.
See combination meter troubleshooting on page BE±2.
NG Repair bulb or combination meter assembly.
OK