Page 944 of 1943

DI±364
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)C1219/27
(DI±373)
Malfunction in regenerative solenoid (SS) circuitRegenerative solenoid (SS) circuit
Brake actuator
C1220/46
(DI±392)Malfunction in regulator (REG) pressure sensor
C1221/46
(DI±392)Malfunction in front (FR) pressure sensor
Each pressure sensor
Each pressure sensor circuit
Brake actuatorC1222/46
(DI±392)Malfunction in rear (RR) pressure sensor
Brake actuator
C1241/41
(DI±397)Low or abnormally high battery positive voltage in IG1 circuit
Battery
Charging system
Power source circuit
C1242/42*2
(DI±400)Open circuit in IG2 circuit
Battery
Charging system
Power source circuit
C1246/46
(DI±392)Malfunction in master cylinder (M/C) pressure sensorMaster cylinder (M/C) pressure sensor
Master cylinder (M/C) pressure sensor circuit
C1249/49
(DI±403)Open circuit in stop light switch circuitStop light switch
Stop light switch circuit
C1251/51*2
(DI±406)Malfunction in hydraulic brake booster pump motorHydraulic brake booster pump motor
C1252/52*2
(DI±409)Hydraulic brake booster pump motor ON time abnormally long
Hydraulic brake booster pump motor
Hydraulic brake booster pump motor circuit
Pressure switch (PH or PL)
C1253/53*2
(DI±416)Malfunction in hydro motor relay circuitHydro motor relay
Hydro motor relay circuit
C1254/54*2
(DI±421)Malfunction in pressure switchPressure switch (PH or PL)
Pressure switch circuit
C1256/56*2
(DI±424)Malfunction of accumulator low pressure
Accumulator
Pressure switch (PH or PL)
Hydraulic brake booster pump motor
C1257/57*2
(DI±430)Malfunction in power supply drive circuitBattery
Power Source circuit
C1259/59
(DI±433)Malfunction in regenerative of HV ECUHV control system
HV ECU
Always ON
(DI±434)Malfunction in brake ECU
Battery
Charging system
Power source circuit
Brake ECU
*1: As the DTC cannot be erased by replacing parts alone do either of the following operations.
(1) Clear DTC (See page DI±353).
(2) At the vehicle speed of 20 km/h (12 mph), drive the vehicle for 30 sec. or more.
*
2: Using the following table, troubled parts can be specified.
Page 949 of 1943

DI7OK±01
BR3583
BR3582F00010
RotorSpeed Sensor
Magnet
To ECU
+V
±VHigh Speed
Low Speed
CoilNS
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±371
2001 PRIUS (RM778U)
CIRCUIT INSPECTION
DTC
C0200/31 ± C0215/34Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects wheel speed and sends the ap-
propriate signals to the ECU. These signals are used for control
of both the ABS & EBD control system. The front and rear rotors
each have 48 serrations.
When the rotors rotate, the magnetic field emitted by the perma-
nent magnet in the speed sensor generates an AC voltage.
Since the frequency of this AC voltage changes in direct propor-
tion to the speed of the rotor, the frequency is used by the ECU
to detect the speed of each wheel.
DTC No.DTC Detecting ConditionTrouble Area
C0200/31
C0205/32
C0210/33
C0215/34
Detection of any of conditions 1. through 4.:
1. At vehicle speed of 10 km/h (6 mph) or more, pulses are
not input for 15 sec. or more.
2. While a vehicle is driven at a speed of 15 km/h (24 mph)
or more, pulse signals from the speed sensor are
instantly omitted 7 times or more.
3. While a vehicle is driven at a speed of 20 km/h (32 mph)
or more, error signals from the speed sensor are trans-
mitted consecutively 75 time or more within 5 min.
4. When the ignition switch is ON, an open circuit in the
speed sensor continues for 0.5 sec. or more.
Right front, left front, right rear and left rear speed sensor
Each speed sensor circuit
Sensor rotor
HINT:
DTC No. C0200/31 is for the right front speed sensor.
DTC No. C0205/32 is for the left front speed sensor.
DTC No. C0210/33 is for the right rear speed sensor.
DTC No. C0215/34 is for the left rear speed sensor.
Page 950 of 1943
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
Page 951 of 1943

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
Page 952 of 1943

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
Page 953 of 1943
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
Page 954 of 1943

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.
Page 955 of 1943
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.