brake sensor TOYOTA SIENNA 2007 Service Manual PDF

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–9
BC
PROBLEM SYMPTOMS TABLE
If there are no DTCs output but the problem still occurs,
check the circuits for each problem symptom in the order
given in the table below and proceed to the relevant
troubleshooting page.
NOTICE:
When replacing the brake actuator assembly, sensor,
etc., turn the ignition switch off.
HINT:
Inspect the fuse and relay before investigating the suspected
areas as shown in the table below. Inspect each malfunction
circuit in numerical order for the corresponding symptom.
Anti-lock brake system:
Symptom Suspected Area See page
ABS does not operate1. Check the DTC again and make sure that the normal
system code is output.BC-10
2. IG power source circuitBC-37
3. Front speed sensor circuitBC-17
4. Rear speed sensor circuitBC-23
5. Check the brake actuator with the intelligent tester. If
abnormal, check the hydraulic circuit for leakage.BC-183
6. If the symptoms still occur even after the above circuits in
suspected areas have been inspected and proved to be
normal, replace the brake actuator assembly.BC-184
ABS does not operate efficiently1. Check the DTC again and make sure that the normal
system code is output.BC-10
2. Front speed sensor circuitBC-17
3. Rear speed sensor circuitBC-23
4. Stop light switch circuitBC-41
5. Check the brake actuator with intelligent tester. If abnormal,
check that hydraulic circuit for leakage.BC-183
6. If the symptoms still occur even after the above circuits in
suspected areas have been inspected and proved to be
normal, replace the brake actuator assembly.BC-184
ABS warning light abnormal (Remains on)1. ABS warning light circuitBC-47
2. Brake actuator assemblyBC-184
ABS warning light abnormal (Does not come on)1. ABS warning light circuitBC-50
2. Brake actuator assemblyBC-184
BRAKE warning light abnormal (Remains on)1. BRAKE warning light circuitBC-52
2. Brake actuator assemblyBC-184
BRAKE warning light abnormal (Does not come on)1. BRAKE warning light circuitBC-59
2. Brake actuator assemblyBC-184
DTC check cannot be done1. Check the DTC again and make sure that the normal
system code is output.BC-10
2. TC and CG terminal circuitBC-61
3. If the symptoms still occur even after the above circuits in
suspected areas have been inspected and proved to be
normal, replace the brake actuator assembly.BC-184
Test mode (Signal check) cannot be done1. TS and CG terminal circuitBC-64
2. Brake actuator assemblyBC-184

BC–4BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
TEST MODE PROCEDURE
1. SPEED SENSOR SIGNAL CHECK (WHEN USING SST
CHECK WIRE):
HINT:
• If the ignition switch is turned from the ON to the ACC
or LOCK position during Test Mode, the DTCs of the
signal check function will be erased.
(a) Turn the ignition switch off.
(b) Check that the steering wheel is in the straight-
ahead position and move the shift lever to the P
position (Automatic Transmission) or apply the
parking brake (Manual Transmission).
(c) Using SST, connect terminals TS and CG of the
DLC3.
SST 09843-18040
(d) Turn the ignition switch to the ON position.
(e) Check that the ABS warning light is blinking in the
Test Mode.
HINT:
If the ABS warning light does not blink, inspect the
TS and CG terminal circuit and the ABS warning
light circuit.
(f) Start the engine.
(g) Using SST, perform the speed sensor signal check
in Test Mode.
SST 09843-18040
(h) Drive the vehicle straight forward.
(i) Accelerate the vehicle to a speed of 28 mph (45 km/
h) or higher for several seconds and check that the
ABS warning light goes off.
HINT:
The signal check may not be completed if the
vehicle has its wheels spun.
(j) Stop the vehicle.
NOTICE:
• The speed sensor signal check may not be
completed if the steering wheel is turned or
the wheels are spun during the check.
G022987E07
BR03904E13
Trouble Area See procedure
TS and CG terminal circuitBC-64
ABS warning light circuitBC-47 or BC-50

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–5
BC
• After the ABS warning light goes off and if
vehicle speed exceeds 50 mph (80 km/h), the
signal check code will be stored again.
Decelerate or stop the vehicle before the
speed reaches 50 mph (80 km/h).
• If the signal check has not been completed,
the ABS warning light blinks while driving
and the ABS system does not operate.
HINT:
When the signal check has been completed, the
ABS warning light goes off while driving and blinks
in the Test Mode pattern while stationary.
2. READ DTC
(a) Using SST, connect terminals TC and CG of the
DLC3.
SST 09843-18040
(b) Read the number of blinks of the ABS warning light.
HINT:
• See the list of DTC.
• If every sensor is normal, the normal system
code is output. (A cycle of 0.25 second ON and
0.25 second OFF is repeated.)
• If more than 1 malfunction is detected at the
same time, the lowest numbered code will be
displayed first.
(c) After performing the check, disconnect the SST
from terminals TS and CG, TC and CG of the DLC3
and turn the ignition switch off.
3. DTC OF TEST MODE (SIGNAL CHECK) FUNCTION
G022986E01
I042842E02
Code No. Diagnosis Trouble Area
C1271/71 Low output signal of front speed sensor RH• Front speed sensor RH
• Sensor installation
• Speed sensor rotor
C1272/72 Low output signal of front speed sensor LH• Front speed sensor LH
• Sensor installation
• Speed sensor rotor
C1273/73 Low output signal of rear speed sensor RH• Rear speed sensor RH
• Sensor installation
• Speed sensor rotor

BC–6BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
HINT:
The codes in this table are output only in Test Mode
(signal check).
4. SPEED SENSOR SIGNAL CHECK (WHEN USING
INTELLIGENT TESTER):
HINT:
• If the ignition switch is turned from the ON to the ACC
or LOCK position during Test Mode, DTCs of the
signal check function will be erased.
• During Test Mode, the ECU records all DTCs of the
signal check function. By performing the signal check,
the codes are erased if normality is confirmed. The
remaining codes are the codes where an abnormality
was found.
(a) Turn the ignition switch off.
(b) Check that the steering wheel is in the straight-
ahead position.
(c) Connect the intelligent tester to the DLC3.
(d) Turn the ignition switch to the ON position.
(e) Set the intelligent tester to Test Mode (select
"SIGNAL CHECK").
HINT:
Refer to the intelligent tester operator's manual for
further details.
C1274/74 Low output signal of rear speed sensor LH• Rear speed sensor LH
• Sensor installation
• Speed sensor rotor
C1275/75Abnormal change in output signal of front speed sensor
RHSpeed sensor rotor
C1276/76Abnormal change in output signal of front speed sensor
LHSpeed sensor rotor
C1277/77Abnormal change in output signal of rear speed sensor
RHSpeed sensor rotor
C1278/78Abnormal change in output signal of rear speed sensor
LHSpeed sensor rotor Code No. Diagnosis Trouble Area
E144486E01

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–7
BC
(f) Check that the ABS warning light is blinking in the
Test Mode.
HINT:
If the ABS warning light does not blink, inspect the
TS and CG terminal circuit and the ABS warning
light circuit.
(g) Start the engine.
(h) Using the intelligent tester, perform the speed
sensor signal check in Test Mode.
(i) Drive the vehicle straight forward.
(j) Accelerate the vehicle to a speed of 28 mph (45 km/
h) or higher for several seconds and check that the
ABS warning light goes off.
HINT:
The signal check may not be completed if the
vehicle has its wheels spun.
(k) Stop the vehicle.
NOTICE:
• The speed sensor signal check may not be
completed if the steering wheel is turned or
the wheels are spun during the check.
• After the ABS warning light goes off and if
vehicle speed exceeds 50 mph (80 km/h), a
signal check code will be stored again.
Decelerate or stop the vehicle before the
speed reaches 50 mph (80 km/h).
• If the signal check has not been completed,
the ABS warning light blinks while driving
and the ABS system does not operate.
HINT:
When the signal check has been completed, the
ABS warning light goes off while driving and blinks
in the Test Mode pattern while stationary.
5. READ DTC
(a) Read the DTC(s) by following the tester screen.
HINT:
• Refer to the intelligent tester operator's manual
for further details.
• See the list of DTC.
6. DTC OF TEST MODE (SIGNAL CHECK) FUNCTION
BR03904E13
Trouble Area See procedure
TS and CG terminal circuitBC-64
ABS warning light circuitBC-47 or BC-50
Code No. Diagnosis Trouble Area
C1271/71 Low output signal of front speed sensor RH• Front speed sensor RH
• Sensor installation
• Speed sensor rotor
C1272/72 Low output signal of front speed sensor LH• Front speed sensor LH
• Sensor installation
• Speed sensor rotor
C1273/73 Low output signal of rear speed sensor RH• Rear speed sensor RH
• Sensor installation
• Speed sensor rotor

BC–8BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
HINT:
The codes in this table are output only in Test Mode
(signal check).
C1274/74 Low output signal of rear speed sensor LH• Rear speed sensor LH
• Sensor installation
• Speed sensor rotor
C1275/75Abnormal change in output signal of front speed sensor
RHSpeed sensor rotor
C1276/76Abnormal change in output signal of front speed sensor
LHSpeed sensor rotor
C1277/77Abnormal change in output signal of rear speed sensor
RHSpeed sensor rotor
C1278/78Abnormal change in output signal of rear speed sensor
LHSpeed sensor rotor Code No. Diagnosis Trouble Area

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–25
BC
DESCRIPTION
Refer to DTCs C0200/31, C0205/32, C1235/35, and C1236/36 (See page BC-17).
DTCs C1273/73 to C1278/78 can be deleted when the speed sensor sends a vehicle speed signal or the
Test Mode ends. DTCs C1273/73 to C1278/78 are output only in the Test Mode.
HINT:
• DTC C0210/33 and C1238/38 are for the rear speed sensor RH.
• DTC C0215/34 and C1239/39 are for the rear speed sensor LH.
DTC C0210/33 Rear Speed Sensor RH Circuit
DTC C0215/34 Rear Speed Sensor LH Circuit
DTC C1238/38Foreign Object is Attached on Tip of Rear
Speed Sensor RH
DTC C1239/39Foreign Object is Attached on Tip of Rear
Speed Sensor LH
DTC C1273/73Low Output Signal of Rear Speed Sensor RH
(Test Mode DTC)
DTC C1274/74Low Output Signal of Rear Speed Sensor LH
(Test Mode DTC)
DTC C1277/77Abnormal Change in Output Signal of Rear
Speed Sensor RH (Test Mode DTC)
DTC C1278/78Abnormal Change in Output Signal of Rear
Speed Sensor LH (Test Mode DTC)
DTC No. DTC Detection Condition Trouble Area
C0210/33
C0215/34With vehicle speed at 10 km/h (6 mph) or more, sensor
signal circuit of faulty wheel is open or short for 1
second or more.
• Momentary interruption of sensor signal of faulty
wheel has occurred 7 times or more.
• Sensor signal circuit is open for 0.5 seconds or
more.• Rear speed sensor RH/LH
• Rear speed sensor RH/LH circuit
• Speed sensor rotor
• Sensor installation
• Brake actuator assembly
C1238/38
C1239/39At vehicle speed of 20 km/h (12 mph) or more, condition
that noise is included in speed sensor signal continues
for 5 seconds or more.• Rear speed sensor RH/LH
• Speed sensor rotor
• Sensor installation
• Brake actuator assembly

BC–26BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1 when using the intelligent tester and start from step 3 when not using the
intelligent tester.
(a) Select the DATA LIST mode on the intelligent tester.
ABS:
(b) Check that there is the speed value output from the
speed sensor displayed on the intelligent tester and the
speed value displayed on the speedometer are almost
the same when driving the vehicle.
OK:
The speed value output from the speed sensor
displayed on the intelligent tester is the same as
the actual vehicle speed.
NG
OK
1READ VALUE OF INTELLIGENT TESTER (REAR SPEED SENSOR)
F040100E03
Item (Display)Measurement Item / Range
(Display)Normal Condition Diagnostic Note
WHEEL SPD RRWheel speed sensor (RR) reading
/ min.: 0 km/h (0 mph), max.: 326
km/h (202 mph)Actual wheel speedSimilar speed as indicated on
speedometer
WHEEL SPD RLWheel speed sensor (RL) reading
/ min.: 0 km/h (0 mph), max.: 326
km/h (202 mph)Actual wheel speedSimilar speed as indicated on
speedometer
Go to step 3

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–27
BC
(a) Clear the DTC (See page BC-10).
(b) Perform sensor signal check in TEST MODE
PROCEDURE (See page BC-3).
OK:
All Test Mode DTCs are erased.
OK
NG
(a) Turn the ignition switch off.
(b) Check the speed sensor installation.
OK:
The installation nut is tightened properly.
There is no clearance between the sensor and the
rear axle.
To r q u e :
8.0 N*m (82 kgf*cm, 71 in.*lbf)
NOTICE:
Check the speed sensor signal after replacement
(See page BC-3).
NG
OK
(a) Remove the rear speed sensor (See page BC-190).
(b) Check the sensor tip.
OK:
No scratches or foreign matter on the sensor tip.
NOTICE:
Check the speed sensor signal after cleaning or
replacement (See page BC-3).
NG
OK
2PERFORM TEST MODE INSPECTION (SIGNAL CHECK)
Go to step 8
3INSPECT REAR SPEED SENSOR INSTALLATION
BR03795E21
INSTALL REAR SPEED SENSOR
CORRECTLY
4INSPECT SPEED SENSOR TIP
CLEAN OR REPLACE REAR SPEED
SENSOR

BC–28BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
(a) Install the rear speed sensor.
(b) Disconnect the rear speed sensor connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance
RH:
LH:
NOTICE:
Check the speed sensor signal after replacement
(See page BC-3).
NG
OK
5INSPECT HARNESS AND CONNECTOR (BETWEEN REAR SPEED SENSOR AND SKID
CONTROL SENSOR WIRE)
F041836
Tester Connection Specified Condition
2 (RR-) - 1 (RR+) 1.09+-0.2 k
at 20C
2 (RR-) - Body ground 10 k
or higher
1 (RR+) - Body ground 10 k
or higher
Tester Connection Specified Condition
2 (RL-) - 1 (RL+) 1.09+-0.2 k
at 20C
2 (RL-) - Body ground 10 k
or higher
1 (RL+) - Body ground 10 k
or higher
REPLACE REAR SPEED SENSOR