engine TOYOTA PRIUS 2001 Service Repair Manual

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

A14009
ON
SPD
(+) (±)
AT7809
4.5 ~ 5.5 V
0
DI±106
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedmeter in the combination meter is normal.
HINT:
The ABS ECU is operating normally if the speedometer display is normal.
NG Check and replace combination meter (See
page BE±2) and ABS ECU (See page
IN±41).
OK
2 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Remove the ECM with connector still connected (See
page SF±62).
(b) Drive the vehicle.
CHECK:
Measure voltage between terminal SPD of ECM connector and
body ground when the wheel is turned slowly.
OK:
Voltage is generated intermittently.
NG Check and repair harness and connector
between combination meter and ECM.
OK
Check and replace ECM (See page IN±41).

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

A03403A03404A03675
M+ Signal Waveform
5 V/
Division
GND
1 msec./Division
M± Signal Waveform
GND
5 V/
Division
1 msec./Division
± DIAGNOSTICSENGINE
DI±109
2001 PRIUS (RM778U)
1 Check throttle control motor circuit.
PREPARATION:
(a) Connect the oscilloscope between terminals M+ or M±
and E1 of the ECM connectors.
(b) Start the engine.
CHECK:
Check the waveform between terminals M+ or M± and E1 of the
ECM connectors when the engine is idling.
OK:
The correct waveforms are as shown.
HINT:
The waveform frequency varies depending on the throttle
opening.
OK Check and replace ECM (See page IN±41).
NG
2 Check throttle control motor (See page SF±24).
NG Replace throttle control motor with magnetic
clutch (See page SF±29).
OK
3 Check for open and short in harness and connector between throttle control mo-
tor and ECM (See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±41).

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

A13630THRO FuseR/B No.2
A13631
BM
(+)(±)
± DIAGNOSTICSENGINE
DI±111
2001 PRIUS (RM778U)
1 Check THRO fuse of R/B No.2.
PREPARATION:
Remove the THRO fuse from the Engine room J/B.
CHECK:
Check the countinuity of the THRO fuse.
OK:
Continuity
NG Check for short in all harness and components
connected to THRO fuse.
OK
2 Check voltage between terminal +BM of ECM connector and body ground.
PREPARATION:
Remove the ECM with connector still connected (See page
SF±62).
CHECK:
Measure the voltage between terminal BM of the ECM connec-
tor and body ground.
OK:
Voltage: 9 ± 14 V
OK Check and replace ECM (See page IN±41).
NG
Check and repair harness or connector be-
tween battery and ETCS fuse, and ETCS fuse
and ECM (See page IN±41).

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

± DIAGNOSTICSENGINE
DI±113
2001 PRIUS (RM778U)
OK
Replace throttle body.

± DIAGNOSTICSENGINE
DI±115
2001 PRIUS (RM778U)
DTC P1300 Igniter Circuit Malfunction (No.1)
DTC P1305 Igniter Circuit Malfunction (No.2)
DTC P1310 Igniter Circuit Malfunction (No.3)
DTC P1315 Igniter Circuit Malfunction (No.4)
CIRCUIT DESCRIPTION
A DIS (Direct Ignition System) has been adopted. The DIS improves the ignition timing accuracy, reduces
high±voltage loss, and enhances the the overall reliability of the ignition system by eliminating the distributor.
The DIS is a 1±cylinder ignition system which ignites one cylinder with one ignition coil. In the 1±cylinder
ignition system, the one spark plug is connected to the end of the secondary winding. High voltage generated
in the secondary winding is applied directly to the spark plug. The spark of the spark plug pass from the center
elecrtode to the ground electrode.
The ECM determines ignition timing and outputs the ignition signals (IGT) for each cylinder. Based on IGT
signals, the power transistors in the igniter cuts off the current to the primary coil in the ignition coil is supplied
to the spark plug that are connected to the end of the secondary coil. At the same time, the igniter also sends
an ignition confirmation signal (IGF) as a fail±safe measure to the ECM.
DTC No.DTC Detecting ConditionTrouble Area
P1300
P1305
P1310
P1315
No IGF signal to ECM while engine is running

Ignition system

Open or short in IGF1 and IGT1 ± 4 circuit from
ignition coil with igniter

No.1 ± No.4 ignition coil with igniter

ECM
DI6VI±02

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.