O2 sensor TOYOTA PRIUS 2001 Service Repair Manual

F12670
Brake ECU
A4
Speed Sensor
Front LH
P
L15 16
11 2 1 2
1
1
2
2 1FR+FL±
FR±
RR+ FL+
RR±RL+
RL± 5R
G
BR
14 B10
13
Y
BR19
20
B1112 (Shielded)
BR±B IB1

B11B11 B11 B11
RSS 21FSS 24 B10
B10
B10
B10
(Shielded)
(Shielded) (Shielded)
(Shielded)
(Shielded)P
L P
LIB1 IB1 2
1 A5
Speed Sensor
Front RH
A23
Speed Sensor
Rear LH
A24
Speed Sensor
Rear RH DI±372
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
WIRING DIAGRAM

R14205
1
2
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±373
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:
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 the TOYOTA hand±held tester.
1 Check output value of speed sensor.
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 DATALIST mode on the TOYOTA hand±held tester.
CHECK:
Check that there is no difference between the speed value output from the speed sensor displayed on the
TOYOTA hand±held tester and the speed value displayed on the speedometer when driving the vehicle.
OK:
There is almost no difference from the displayed speed value.
HINT:
There is tolerance of ± 10 % in the speedometer indication.
OK Check and replace brake ECU.
NG
2 Check speed sensor.
Front:
PREPARATION:
(a) Remove the front fender liner.
(b) Make sure that there is no looseness at the connector
lock part and connecting part of the connector.
(c) Disconnect the speed sensor connector.
CHECK:
Measure resistance between terminals 1 and 2 of speed sensor
connector.
OK:
Resistance: 0.6 ± 2.5 kW
CHECK:
Measure resistance between terminals 1 and 2 of speed sensor
connector and body ground.
OK:
Resistance: 10 MW or higher

F10179
1
2
F10180
Connector 1
12
Connector 2
1
2
DI±374
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
Rear:
PREPARATION:
(a) Make sure that there is no looseness at the connector
lock part and connecting part of the connector.
(b) Disconnect the speed sensor connector at hub bearing .
CHECK:
Measure resistance between terminals 1 and 2 of speed sensor
connector.
OK:
Resistance: 0.7 ± 2.2 kW
CHECK:
Measure resistance between terminals 1 and 2 of speed sensor
connector and body ground.
OK:
Resistance: 1 MW or higher
Rear speed sensor sub±wire harness:
PREPARATION:
(a) Remove the seat cushion and seatback.
(b) Make sure that there is no looseness at the connector
lock part and connecting part of the connector.
(c) Disconnect the speed sensor connector inside vehicle.
CHECK:
(a) Measure resistance between terminal 1 of connector 1
and terninal 2 of connector 2.
(b) Measure resistance between terminal 2 of connector 1
and terninal 1 of connector 2.
OK:
Resistance: below 1 W
CHECK:
Measure resistance between terminals 1 and 2 of speed sensor
connector 1 and body ground.
OK:
Resistance: 10 MW or higher
NG Replace speed sensor or sub±wire harness.
NOTICE:
Check the speed sensor signal last (See page DI±353).
OK

BR3795F10178
F10452
Front
Rear OK
NG OKNG
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±375
2001 PRIUS (RM778U)
3 Check for open and short circuit in harness and connector between each speed
sensor and brake ECU (See page IN±41).
NG Repair or replace harness or connector.
OK
4 Check speed sensor installation.
CHECK:
Check the speed sensor installation.
OK:
The installation bolt is tightened properly and there is
no clearance between the sensor and steering
knuckle or rear axle carrier.
Torque:
Front speed sensor : 8.0 N´m (82 kgf´cm, 71 in.´lbf)
NG Replace speed sensor.
NOTICE:
Check the speed sensor signal last (See page DI±353).
OK

W04200
Normal Signal Waveform
1 V / Division2 m/s / DivisionGND
R00948
DI±376
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
5 Check speed sensor and sensor rotor serrations.
REFERENCE: INSPECTION USING OSCILLOSCOPE
PREPARATION:
(a) Remove the brake ECU with connectors still connected.
(b) Connect the oscilloscope to the terminals FR+, FL+, RR+
or RL+ and GND of the brake ECU.
CHECK:
Drive the vehicle with about 20 km/h (12 mph), and check the
signal waveform.
HINT:

As the vehicle speed (rpm of the wheels) increases, a
cycle of the waveform becomes shorter and the fluctua-
tion in the output voltage becomes greater.

When noise is identified in the waveform on the oscillo-
scope, error signals are generated due to the speed sen-
sor rotor's scratches, looseness or foreign matter depos-
ited on it.
OK Check and replace brake ECU.
NG
6 Check sensor rotor and sensor tip.
Front:
PREPARATION:
Remove the front drive shaft (See page SA±17).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches or missing teeth or foreign objects.
PREPARATION:
Remove the front speed sensor (See page BR±53).
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
HINT:
If foreign matter (including that on the sensor rotor side) is iden-
tified, remove it and after reassembling, check the output wave-
form.

W04846
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±377
2001 PRIUS (RM778U)
Rear:
PREPARATION:
Remove the rear speed sensor (See page BR±56).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches or missing teeth or foreign objects.
HINT:
If the sensor rotor is damaged or deformed, replace the hub as-
sembly.
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
HINT:
If foreign matter (including that on the sensor rotor side) is iden-
tified, remove it and after reassembling, check the output wave-
form.
NG Replace sensor rotor or speed sensor.
NOTICE:
Check the speed sensor signal last (See page DI±353).
OK
Check and replace brake ECU.

± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±397
2001 PRIUS (RM778U)
DTCC1220±C1222/C1246/46Each Hydraulic Pressure Sensor Cir-
cuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1220/46
Either of the following 1. or 2. is detected:
1. When the ignition switch is ON, the condition that the
voltage of the terminal PREG in brake ECU is 0.14 V or
less or 4.85 V or more, or that of terminal VREG is 4.4 V
or less or 5.6 V or more continues for 1.2 sec. or more.
2. At a vehicle speed of 15 km/h (24 mph) or more, when
both the brake switch and hydro motor are OFF, the
voltage ratio of the terminal PREG to VREG of brake
ECU is 0.06 or less or 0.14 or more continues for 8 sec.
and this condition occurs consecutively 10 times.

Regulator (REG) pressure sensor

Regulator (REG) pressure sensor circuit

Brake actuator
C1221/46
Either of the following 1. or 2. is detected:
1. When the ignition switch is ON, the condition that the
voltage of the terminal PFR in brake ECU is 0.14 V or
less or 4.85 V or more, or that of terminal VFR is 4.4 V
or less or 5.6 V or more continues for 1.2 sec. or more.
2. At a vehicle speed of 15 km/h (24 mph) or more, when
both the brake switch and hydro motor are OFF, the
voltage ratio of the terminal PFR to VFR of brake ECU is
0.06 or less or 0.14 or more continues for 8 sec. and this
condition occurs consecutively 10 times.

Front (FR) pressure sensor

Front (FR) pressure sensor circuit

Brake actuator
C1222/46
Either of the following 1. or 2. is detected:
1. When the ignition switch is ON, the condition that the
voltage of the terminal PRR in brake ECU is 0.14 V or
less or 4.85 V or more, or that of terminal VRR is 4.4 V
or less or 5.6 V or more continues for 1.2 sec. or more.
2. At a vehicle speed of 15 km/h (24 mph) or more, when
both the brake switch and hydro motor are OFF, the
voltage ratio of the terminal PRR to VRR of brake ECU
is 0.06 or less or 0.14 or more continues for 8 sec. and
this condition occurs consecutively 10 times.

Rear (RR) pressure sensor

Rear (RR) pressure sensor circuit

Brake actuator
C1246/46
Either of the following 1. or 2. is detected:
1. When the ignition switch is ON, the condition that the
voltage of the terminal PMC in brake ECU is 0.14 V or
less or 4.85 V or more, or that of terminal VMC is 4.4 V
or less or 5.6 V or more continues for 1.2 sec. or more.
2. At a vehicle speed of 15 km/h (24 mph) or more, when
both the brake switch and hydro motor are OFF, the
voltage ratio of the terminal PMC to VMC of brake ECU
is 0.06 or less or 0.14 or more continues for 8 sec. and
this condition occurs consecutively 10 times.

Master cylinder (M/C) pressure sensor

Master cylinder (M/C) pressure sensor circuit

Brake actuator
DI296±06

± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±399
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:
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 the TOYOTA hand±held tester.
1 Check output value of the each pressure sensor.
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 DATALIST mode on the TOYOTA hand±held tester.
CHECK:
Check that the brake fluid pressure value of the master cylinder pressure sensor, regulator pressure sensor,
front pressure sensor and rear pressure sensor displayed on the TOYOTA hand±held tester is changing
when depressing the brake pedal.
OK:
Brake fluid pressure value must be changing.
OK Go to step 4.
NG

F12669
ON
E
2
FRR
PREG
PFR
PMC
EREGERR
EFR
DI±400
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
2 Check each pressure sensor.
PREPARATION:
(a) Install the LSPV gauge to the front caliper bleeder plug
portion, and bleed LSPV gauge.
SST 09709±29018
(b) Remove the brake ECU with connectors still connected.
CHECK:
Turn the ignition switch ON and depress the brake pedal, then
check the relation between the fluid pressure and voltage of ter-
minals of each pressure sensor shown below with the connec-
tor still connected.
Pressure sensor nameSymbols
Master cylinder pressure sensorPMC ± E2
Regulator pressure sensorPREG ± EREG
Front pressure sensorPFR ± EFR
Rear pressure sensorPRR ± ERR
OK:
Front brake caliper fluid pressureVoltage
0 kPa (0 Kgf/cm2, 0 psi)0.37 ± 0.63 V
5,883 kPa (60 kgf/cm2, 853 psi)1.57 ± 1.83 V
11,768 kPa (120 kgf/cm2, 1,706 psi)2.77 ± 3.03 V
HINT:
It should be taken into account that the difference in voltage be-
tween terminals is caused by the slightly different pressure ap-
plied to each pressure sensor.
OK Go to step 4.
NG
3 Check for open and short circuit in harness and connector between each pres-
sure sensor and brake ECU (See page IN±41).
NG Repair or replace harness or connector.
OK
Replace brake actuator.

F12687
DLC3
2DTs 4
Ts
8
4 CG14ID1GR±G
B11
W±B
AJ11
J/C
A
ID
C Instrument Panel J/BBrake ECU
J16
J/C
J24
J/CB
W±B W±B
A2K 8 3
GR±G GR±G
B DI±454
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
Ts Terminal Circuit
CIRCUIT DESCRIPTION
The sensor check circuit detects abnormalities in the speed sensor signal which cannot be detected by the
DTC check.
Connecting terminals Ts and CG of the DLC3 starts the check.
WIRING DIAGRAM
DI29J±12