2001 TOYOTA PRIUS Service Repair Manual

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.

DI±378
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
DTCC0226/21 ± C0246/23ABS Solenoid Circuit
DTC
C1217/25 ± C1219/27Regenerative Solenoid Circuit
CIRCUIT DESCRIPTION
This solenoid goes on when signals are received from the ECU and controls the pressure acting on the wheel
cylinders thus controlling the braking force.
DTC No.DTC Detecting ConditionTrouble Area
C0226/21Open or short circuit in SFRH or SFRR circuit continues for
0.05 sec. or more.
SFRH or SFRR circuit

Brake actuator
C0236/22Open or short circuit in SFLH or SFLR circuit continues for
0.05 sec. or more.
SFLH or SFLR circuit

Brake actuator
C0246/23Open or short circuit in SRR or SRH circuit continues for
0.05 sec. or more.
SRR or SRH circuit

Brake actuator
C1217/25Open or short circuit in SMC1 circuit continues for 0.05 sec.
or more.
SMC1 circuit

Brake actuator
C1218/26Open or short circuit in SMC2 circuit continues for 0.05 sec.
or more.
SMC2 circuit

Brake actuator
C1219/27Open or short circuit in SS circuit continues for 0.05 sec. or
more.
SS circuit

Brake actuator
DI28Z±13

F12671
Brake ECU
SFRH
SFRR
SFLH
SFLR Engine Room
R/B No. 3
19
5 1121
4 W±R
2 1 4
3
7 14
IER1+
SR
8 W±B
F102
Brake Actuator 1
A
Battery10R±W
Y±B
G±W
G±O G±B
B39
32 5
12
R±Y ABS No. 1
BS
SFRR
SFLH
SFLR
SRRH
SRRR
SMC1
SS J1
J/C1
4 W
3 FL
Block
No. 1 2
1
B3 B3 B2
B3 B2 B3 B3B3B11 IA2
R±L R±G R±B SFRH
SMC2Y±B
Y±B
3
B10SRRH
SRRR
SMC1
SS SMC2 9
B10B10 B10B10 B10B10 B10B10 B10 B±L7
3
3
3
3 36
J7
J/C
W±B AA
B2 3
3Engine
Room
R/B No. 3
F131
1
B±G
1
FL
Block
No. 2ABS Solenoid Relay
R
DC/DC
MAIN
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±379
2001 PRIUS (RM778U)
WIRING DIAGRAM