Page 521 of 1897
BR0LU-02
F09738
Sensor Rotor
Front Speed Sensor
N´m (kgf´cm, ft´lbf): Specified torque
8.0 (82, 71 in.´lbf)
5.4 (55, 48 in.´lbf)
- BRAKEFRONT SPEED SENSOR
BR-59
1458 Author: Date:
2001 AVALON (RM808U)
FRONT SPEED SENSOR
COMPONENTS
Page 612 of 1897
BR3583
BR3582F00010
RotorSpeed Sensor
Magnet
To ECU
+V
-VHigh Speed
Low Speed
CoilNS
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)DI-225
381 Author: Date:
2001 AVALON (RM808U)
DTC 31 - 36, 38, 39 Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects wheel speed and sends the ap-
propriate signals to the ECU. These signals are used to control
the ABS system. Each of the front and rear rotors has 48 serra-
tions.
When the rotors rotate, a magnetic field emitted by a permanent
magnet in the speed sensor generates an AC voltage. Since
the frequency of this AC voltage changes in direct proportion to
the speed of the rotor, the frequency is used by the ECU to de-
tect the speed of each wheel.
DTC No.DTC Detecting ConditionTrouble Area
31, 32, 33, 34
When any of the following 1. through 3. is detected:
1. Vehicle speed is more than 40 km/h (25 mph), and
pulses are not input for 0.01 sec.
2. After the initial start or restart and when the vehicle
speed has reached 12 km/h (7 mph), the wheel speed of
0 km/h (0 mph) is detected.
3. After the initial start or restart and when the vehicle
speed has reached 18 km/h (11 mph), the front wheel
speed of 0 km/h (0 mph) is detected.
Right front, left front, right rear, left rear speed sensor
Each speed sensor circuit
Sensor installation
35, 36, 38, 39Detecting abnormality in the resistance value of each speed
sensor.Right front, left front, right rear, left rear speed sensor
Each speed sensor circuit
HINT:
DTC No. 31 and 35 are for the right front speed sensor.
DTC No. 32 and 36 are for the left front speed sensor.
DTC No. 33 and 38 are for the right rear speed sensor.
DTC No. 34 and 39 are for the left rear speed sensor.
DI6NF-02
Page 615 of 1897
BR3795
OK NG OK NG
OK NGOK NG
W04200
Normal Signal Waveform
2 m/s / DivisionGND
1 V / Division
DI-228- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
384 Author: Date:
2001 AVALON (RM808U)
2 Check for open and short circuit in harness and connector between each speed
sensor and ABS ECU (See page IN-30).
NG Repair or replace harness or connector.
OK
3 Check speed sensor installation.
CHECK:
Check the speed sensor installation.
OK:
The installation bolt shall be tightened properly and
there is no clearance is allowed between the sensor
and front steering knuckle or rear axle carrier.
NG Replace speed sensor.
NOTICE:
Check the speed sensor signal last (See page DI-212).
OK
4 Check speed sensor and sensor rotor serrations.
REFERENCE: INSPECTION USING OSCILLOSCOPE
PREPARATION:
(a) Disconnect the connector from the brake actuator.
(b) Connect the oscilloscope to the terminals FR+, FL+, RR+
or RL+ and GND of the ABS ECU harness side connector.
CHECK:
Drive the vehicle at about 30 km/h (19 mph), and check the sig-
nal waveform.
OK Check and replace ABS ECU.
NG
Page 616 of 1897
R00948
R00947
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)DI-229
385 Author: Date:
2001 AVALON (RM808U)
5 Check sensor rotor and sensor tip.
Front:
PREPARATION:
Remove the front drive shaft (See page SA-16).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches, missing teeth or foreign objects.
PREPARATION:
Remove the front speed sensor (See page BR-60).
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
Rear:
PREPARATION:
Remove the axle hub (See page SA-45).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches, missing teeth or foreign objects.
PREPARATION:
Remove the rear speed sensor (See page BR-63).
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
NG Replace sensor rotor or speed sensor.
NOTICE:
Check the speed sensor signal last (See page DI-212).
OK
Check and replace ABS ECU.
Page 617 of 1897
DI-230- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
386 Author: Date:
2001 AVALON (RM808U)
DTC 37 Speed Sensor Rotor Faulty
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
37
When any of the following 1. through 3. is detected:
1. Occurrence of wheel speed difference between the front
and rear wheels of either left or right side of the vehicle
and the front left and right wheels. (Detection of mini tire
size, spinning wheel or decelerating wheel.)
2. Continuous ABS control for 60 sec. or more.
3. Interference on 1 or more wheels for 20 sec. with the
brake pedal depressed, or for 5 sec. when the brake
pedal is not depressed.
Speed sensor
Sensor rotor
INSPECTION PROCEDURE
1 Check sensor rotor (See page DI-225).
NG Replace sensor rotor.
OK
2 Check speed sensor (See page DI-225).
NG Replace speed sensor.
OK
3 Check for open or short circuit in harness and connector between speed sensor
and ABS ECU (See page IN-30).
NG Repair or replace harness and connector.
OK
Check and replace ABS ECU.
DI6NG-01
Page 630 of 1897
DI6N8-01
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)DI-215
371 Author: Date:
2001 AVALON (RM808U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Using SST 09843-18020, connect the terminals Tc and E1.
If any abnormality is found when inspecting parts, inspect the ECU.
If a malfunction code is displayed during the DTC check, check the circuit listed under the code. For
details of each code, refer to the page under respective ºDTC No.º in the DTC chart.
DTC No.
(See Page)Detection ItemTrouble Area
11
(DI-219)Open or short circuit in ABS solenoid relay circuitABS solenoid relay
ABS solenoid relay circuit
13
(DI-221)Open or short circuit in ABS pump motor circuitABS motor relay
ABS motor relay circuit
21
(DI-223)Open or short circuit in brake actuatorBrake actuator
SFRR or SFRH circuit
22
(DI-223)Open or short circuit in brake actuatorBrake actuator
SFLR or SFLH circuit
23
(DI-223)Open or short circuit in brake actuatorBrake actuator
SRRR or SRRH circuit
24
(DI-223)Open or short circuit in brake actuatorBrake actuator
SRLR or SRLH circuit
31*
(DI-225)Right front wheel speed sensor signal malfunction
32*
(DI-225)Left front wheel speed sensor signal malfunctionRight front, left front, right rear and left rear speed sensor
Eh d i it33*
(DI-225)Right rear wheel speed sensor signal malfunction
Each speed sensor circuit
Sensor installation
34*
(DI-225)Left rear wheel speed sensor signal malfunction
35*
(DI-225)Open circuit in right front wheel speed sensor circuitRight front, left front speed sensor
36*
(DI-225)Open circuit in left front wheel speed sensor circuit
Right front, left front s eed sensor
Each speed sensor circuit
37
(DI-230)Speed sensor rotor has wrong number of teeth on one of the 4
wheelsSpeed sensor
Sensor rotor
38*
(DI-225)Open circuit in right rear wheel speed sensor circuitRight rear, left rear speed sensor
39*
(DI-225)Open circuit in left rear wheel speed sensor circuit
Right rear, left rear s eed sensor
Each speed sensor circuit
41
(DI-231)Low and high battery positive voltage
Battery
Charging system
Power source circuit
58
(DI-234)Open circuit in stop light switch circuitStop light switch
Stop light switch circuit
62
(DI-236)Malfunction in ABS ECUABS ECU
Always ON
(DI-238)Malfunction in ABS ECUCharging system
ABS warning light circuit
*: As the DTC cannot only be erased by replacing parts, do either of the following operations.
(1) Clear DTC (See page DI-212).
(2) At a vehicle speed of 20 km/h (12 mph), drive the vehicle for 30 sec. or more.
Page 632 of 1897
DI6N9-01
F07882
Brake Actuator
(w/ ECU, Relay)Front Speed Sensor DLC1
DLC2
Sensor RotorRear Speed Sensor
ABS Warning Light
BRAKE Warning LightSensor Rotor
Front Speed Sensor
Rear Speed Sensor
Stop Light Switch
Sensor RotorActive
Lamp Relay
DI-216- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
372 Author: Date:
2001 AVALON (RM808U)
PARTS LOCATION
Page 635 of 1897
BR3893
Malfunction Code (Example Code 72, 76)
7
26 7
ON
OFF
0.5 sec. 0.5 sec. 0.5 sec. 0.5 sec.1.5 sec.
2.5 sec.
4 sec.
Repeat DI-214
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
370 Author: Date:
2001 AVALON (RM808U)
(9) After completing the check, disconnect the SST
from terminals Tc and E
1 of DLC1, and turn the igni-
tion switch OFF.
SST 09843-18020
DTC of speed sensor check function:
Code No.DiagnosisTrouble Area
71Low output voltage of right front speed sensor
Right front speed sensor
Sensor installation
Right front speed sensor rotor
72Low output voltage of left front speed sensor
Left front speed sensor
Sensor installation
Left front speed sensor rotor
73Low output voltage of right rear speed sensor
Right rear speed sensor
Sensor installation
Right rear speed sensor rotor
74Low output voltage of left rear speed sensor
Left rear speed sensor
Sensor installation
Left rear speed sensor rotor
75Abnormal change in output voltage of right front speed sen-
sorRight front speed sensor rotor
76Abnormal change in output voltage of left front speed sen-
sorLeft front speed sensor rotor
77Abnormal change in output voltage of right rear speed sen-
sorRight rear speed sensor rotor
78Abnormal change in output voltage of left rear speed sensorLeft rear speed sensor rotor
