2001 TOYOTA PRIUS air condition

A14054
11 1A 6
1K
BR 3
1BG±R
1
2 CAIA2
32E9ECM
CCV EVP1
E2
PTNK
VC E7
LE925
2
15V2 VSV
(EVAP)4
TBP Engine Room J/B
B±R 1
1 11F
1 1EFI
Relay
3
2
112
6 B EFI
W±B
BC1
V5 VSV (Purge Flow
Switching Valve) B±G
IE A F12
MAIN
Battery1 5
7 B
BB
C B
4 3
5
2
13
1 1F13
F13
J1
J/CJ7
J/C
A AW±BMREL
29
E9
E8
E9
E818
22 G±R
J/C
J5 J4
IA1 BB19
J4J5 J5J/C
V4
Vapor Pressure
Sensor
Y±RJ8
J/C
Y±R
BC1 BC1 BC1
BC1 BC1BC1
IO1
2
2
2 V6 VSV (Canister Closed Valve)
B
C Y±R
Y±R L±R L±RBRL B±R B CA
AB
R±L
FL Block No. 1
F18
FL Block No. 2 DI±82
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, first troubleshoot DTC P0441,
P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next.

Ask the customer whether, after the MIL came on, the customer found the fuel tank cap loose and tight-
ened it. Also ask the customer whether the fuel tank cap was loose when refuelling. If the fuel tank cap
was loose, it was the cause of the DTC. If the fuel tank cap was not loose or if the customer was not
sure if it was loose, troubleshoot according to the following procedure.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel
ratio was lean or rich, etc. at the time of the malfunction.

DI±88
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)DTC No.
DTC Detecting ConditionTrouble Area
P0441
Pressure in fuel tank does not drop during purge control (2 trip
detection logic)
P0441During purge cut±off, pressure in fuel tank is very low
compared with atmospheric pressure (2 trip detection logic)
Open or short in vapor pressure sensor circuit

Vapor pressure sensor

Open or short in VSV circuit for EVAPWhen VSV for CCV is ONpressure in fuel tank is maintained
Open or short in VSV circuit for EVAP
VSV f EVAPWhen VSV for CCV is ON, pressure in fuel tank is maintained
hi (2id i l i)
VSV for EVAPat atmospheric pressure (2 trip detection logic)
Open or short in VSV circuit for purge flow switching valve
P0446
Turning the VSV for purge flow switching valve is ON does not
lower the pressure sensor output.

Oen or short in VSV circuit for urge flow switching valve

VSV for purge flow switching valve

Charcoal canister cracked, hole or damaged
P0446Although the VSV for purge flow switching valve is OFF, fluc-
tuation in the pressure sensor output is great.
Open or short in VSV circuit for CCV

VSV for CCV

ECMTurning the VSV for CCV OFF does not charge the pressure
sensor output.
ECM
WIRING DIAGRAM
Refer to DTC P0440 on page DI±81.
INSPECTION PROCEDURE
HINT:

If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440,first troubleshoot DTC P0441,
P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel
ratio was lean or rich, etc. at the time of the malfunction.

When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
VSV for EVAP, charcoal canister and vapor pressure sensor.
TOYOTA hand±held tester:
1 Check whether hose close to fuel tank have been modified, and check whether
there are signs of any accident near fuel tank or charcoal canister (See page
DI±81).
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts.
NG Replace to TOYOTA genuine parts.
OK

± DIAGNOSTICSENGINE
DI±103
2001 PRIUS (RM778U)
DTC P0450 Evaporative Emission Control System
Pressure Sensor Malfunction
DTC P0451 Evaporative Emission Control System
Pressure Sensor Range/Performance
CIRCUIT DESCRIPTION
The vapor pressure sensor, VSV for canister closed valve (CCV) and VSV for pressure switching valve are
used to detect abnormalities in the evaporative emission control system.
The ECM decides whether there is an abnormality in the evaporative emission control system based on the
vapor pressure sensor signal.
DTC P0450 or P0451 is recorded by the ECM when the vapor pressure sensor malfunction.
DTC No.DTC Detecting ConditionTrouble Area
P0450
10 seconds or less after engine starting condition (a) or (b)
continues for 7 seconds or more: (2 trip detection logic)
(a) Vapor pressure sensor value < ±4.0 kPa (±30 mmHg, ±1.2
in.Hg)
(b) Vapor pressure sensor value
2.0 kPa (15 mmHg, 0.6
in.Hg)

Open or short in vapor pressure sensor circuit

Vapor pressure sensor
ECM
P0451
Vapor pressure sensor output extremely changes under condi-
tion:
Vehicle speed: 0 km/h (0mph),Engine speed: Idling (2 trip
detection logic)
ECM
WIRING DIAGRAM
Refer to DTC P0440 on page DI±81.
INSPECTION PROCEDURE
HINT:

If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, first trouble shoot DTC P0441,
P0446 P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel
ratio was lean or rich, etc. at the time of the malfunction.

When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
VSV for EVAP, charcoal canister and vapor pressure sensor.
DI7SV±01

A00022
From
Speed Sensor4±Pulse4±Pulse
Combination
MeterECM ABS ECU
A14030
C10
Combination
Meter
2A7
V±W Instrument Panel J/B
6
2B J27G
V±W5
E10ECM
SPD J28G
B
LJ/C
± DIAGNOSTICSENGINE
DI±105
2001 PRIUS (RM778U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
The speed sensor for ABS detects the wheel speed and sends the appropriate signals to the ABS ECU.
The ECU converts these signals into a 4±pulse signal and output it to the combination meter.
After this signal is converted into a more precise rectangular waveform by the waveform shaping circuit in-
side the combination meter, it is then transmitted to the ECM. The determines the vehicle speed based on
the frequency of these pulse signals.
DTC No.DTC Detecting ConditionTrouble Area
P0500
During vehicle is being driven, no vehicle speed sensor signal
to ECM
(2 trip detection logic)

Combination meter

ABS ECU

Open or short in vehicle speed sensor circuit

Vehicle speed sensor

ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
DI6VG±02

A14031
Throttle Control Motor
with Magnetic ClutchECM
(Shielded)
8
E7M+
7
E7M±
30
E7GE01 L
P 2
1 DI±108
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
DTC P1125 Throttle Control Motor Circuit Malfunction
CIRCUIT DESCRIPTION
Throttle motor is operated by the ECM and it opens and closes the throttle valve.
The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the
throttle body and it provides feedback to the ECM to control the throttle motor in order to the throttle valve
opening angle properly in response to driving condition.
If this DTC is stored, the ECM shuts down the power for the throttle motor, and the throttle valve is fully closed
by the return spring.
DTC No.DTC Detecting ConditionTrouble Area
Conditions (a) and (b) continue for 0.5 seconds:
(a) Throttle control motor output duty
80 %
(b) Throttle control motor current < 0.5 A

Open or short in throttle control motor circuit
P1125Throttle control motor current
16 A
Throttle control motor

ECMCondition (a) continues for 0.6 seconds:
(a) Throttle control motor current
7 A
ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel ratio was lean
or rich, etc. at the time of the malfunction.
DI7SW±01

A14032
THROECM
8
BatteryE76
+BM GR
1A B FL Block No. 1Engine Room J/B
2
1B 1
F12 1
F13
B±G
FL Block No. 2
MAIN
1 DI±110
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
DTC P1127 ETCS Actuator Power Source Circuit Mal-
function
CIRCUIT DESCRIPTION
Battery positive voltage is supplied to terminal BM of the ECM even once when the ignition switch is OFF
for the electric throttle control system.
If this DTC is stored, the ECM shuts down the power for the throttle motor, and the throttle valve is fully closed
by the return spring.
DTC No.DTC Detecting ConditionTrouble Area
P1127Open in ETCS power source circuit
Open in ETCS power source circuit

ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel ratio was lean
or rich, etc. at the time of the malfunction.
DI2EC±07

DI±112
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
DTC P1128 Throttle Control Motor Lock Malfunction
CIRCUIT DESCRIPTION
Throttle motor is operated by the ECM and it opens and closes the throttle valve.
The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the
throttle body and it provides feedback to the ECM to control the throttle motor in order the throttle valve open-
ing angle properly in response to driving condition.
If this DTC is stored, the ECM shuts down the power for the throttle motor, and the throttle valve is fully closed
by the return spring.
DTC No.DTC Detecting ConditionTrouble Area
P1128Lock throttle control motor during control throttle control motor
Throttle control motor

Throttle body
WIRING DIAGRAM
Refer to DTC P1125 on page DI±108.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel ratio was lean
or rich, etc. at the time of the malfunction.
1 Check throttle control motor (See page DI±108).
NG Replace throttle control motor
(See page SF±29).
OK
2 Visually check throttle valve.
PREPARATION:
Remove the intake air resonator.
CHECK:
Check whether or not a foreign body is caught between the throttle valve and housing.
NG Remove foreign body and clean throttle body.
DI7SX±01

A14055
BatteryEAN1
Noise
Filter Engine Room J/B
Ignition SW Instrument
Panel J/B3
B±R I4 Ignition Coil
and Igniter No. 4
1ECM
14
Y
E7
E7
E7
E7 13
12
25IGT4
IGT3
IGT2
IGF
E711
IGT1 1
2
4
G
W
B±R
B±R
Y±G 3
4
2 1I3 Ignition Coil
and Igniter No. 3
3
4
2 1I2 Ignition Coil
and Igniter No. 2
2 I1 Ignition Coil
and Igniter No. 1
1
3
4
B±W
B±W
B±W
B±W
B±W
B±W
B±RB±RB±R
B±R
W±B W±B
W±B
W±B
W±B
W±B
B±W
W±B B±W
W±R
B±W IG2 Relay
5
1 3
29
1J
3
1J 2
1A
3
1K
AM2
2
1B
B
F12
12G 11
2B 5
2C 22G 1
B±W
W±R
67
IG2AM2
FL
Block
No. 1
F13
1
B±G
FL
Block
No. 2
MAIN
W±B
A
AJ7
J/C
W±B
A
J1
J/C
IE
B±W
DI±116
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTC P1300 is displayed, check No.1 ignition coil with igniter circuit.

If DTC P1305 is displayed, check No.2 ignition coil with igniter circuit.

If DTC P1310 is displayed, check No.3 ignition coil with igniter circuit.

If DTC P1315 is displayed, check No.4 ignition coil with igniter circuit.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected, when troubleshooting it is useful for
determining whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel
ratio lean or rich, etc. at the time of the malfunction.