TOYOTA AVALON 2001 Service Repair Manual
Page 611 of 1897
DI-224- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
380 Author: Date:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check the DTC once more.
PREPARATION:
(a) Clear the DTC (See page DI-212).
(b) Turn the ignition switch OFF.
CHECK:
Turn the ignition switch ON, and check if the same DTC is stored in the memory.
NO No problem.
YES
Replace ABS ECU.
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 613 of 1897
F09802
ABS Actuator
and ECU
(Shielded)FL+
FL-
FR+
FR-
RL+
RL-
RR+ 2
B-WIE1A77
A76
A75
A74 BR
B-R
B-W
L
J1 J/C (Shielded)
(Shielded) 1 A8
ABS
Speed
Sensor
Front LH
L 2
1 A9
ABS
Speed
Sensor
Front RH1
IE12
IE13
BR
A BR
A
AA
A
BR BR BR
1
2 A29
ABS
Speed
Sensor
Rear LH
1
2 A30
ABS
Speed
Sensor
Rear RH
EEA79
A78
A72
A71
RR- LG
V
(Shielded) (Shielded) (Shielded)
(Shielded) (Shielded) (Shielded)LG
V LG
VBR
BR
IE18
IE17
IE16
IE19
IE110
IE111 ID111
ID122
ID121
IK110
IK112
IK111G
Y G
Y G
Y DI-226
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
382 Author: Date:
2001 AVALON (RM808U)
WIRING DIAGRAM
Page 614 of 1897
R14205
1
2
R14213
1
2
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)DI-227
383 Author: Date:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check speed sensor.
Front:
PREPARATION:
(a) Remove the front fender liner.
(b) Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 0.6 - 2.5 kW (1.6 ± 0.2 kW at 20 °C)
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MW or higher
Rear:
PREPARATION:
(a) Remove the seat cushion and seatback.
(b) Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 1.2 - 2.3 kW (1.6 ± 0.1 kW at 20 °C)
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MW or higher
NG Replace speed sensor.
NOTICE:
Check the speed sensor signal last (See page DI-212).
OK
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 618 of 1897
F09798
Battery W-B
W-BGND1ABS Actuator
and ECU
A715
EE EDY-R
IG1
W-R
ALT
AM1 Driver Side J/B
IG1 RelayECU-IG
No. 2
A719
GND2
A716 1H2
1C4 2
3 1
4 1G1
1B3
W42Ignition Switch
W-L
7IF1
W-L
5
52
1
BEngine Room R/B No. 5
FL Block Engine Room J/B
2H1
2G1
2F4
2F10 B-L
W-B F61
F81
F101
B
FL MAIN IGIG1 AM1
W-B
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)DI-231
387 Author: Date:
2001 AVALON (RM808U)
DTC 41 Power Source Circuit
CIRCUIT DESCRIPTION
This is the power source for the ECU, hence the actuators.
DTC No.DTC Detecting ConditionTrouble Area
41
At a vehicle speed of about 6 km/h (4 mph), low battery
voltage is less than 9.4 V during non-operation of ABS
control or less than 8.8 V during operation of ABS control,
and high battery voltage is more than 17.4 V.Battery
Charging system
Power source circuit
WIRING DIAGRAM
DI6NH-01
Page 619 of 1897
F07886
Driver Side J/B
ECU-IG
No. 2
DI-232- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
388 Author: Date:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check ECU-IG No. 2 fuse.
PREPARATION:
Remove ECU-IG No. 2 fuse from driver side J/B.
CHECK:
Check continuity of ECU-IG No. 2 fuse.
OK:
Continuity
NG Check for short circuit in all the harness and
components connected to ECU-IG No. 2 fuse
(See attached wiring diagram).
OK
2 Check battery positive voltage.
OK:
Voltage: 10 - 14 V
NG Check and repair the charging system (See
page CH-1).
OK
Page 620 of 1897
F00067
(+)(-) ON
A7
151916
F00068
(+) (-) LOCK
A71916
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)DI-233
389 Author: Date:
2001 AVALON (RM808U)
3 Check voltage between terminals IG1 (A7 - 15) and GND (A7 - 16, 19) of the
brake actuator connector.
PREPARATION:
Disconnect the connector from the brake actuator.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure the voltage between terminals A7 - 15 and A7
- 16, 19 of the brake actuator harness side connector.
OK:
Voltage: 10 - 14 V
OK Check and replace ABS ECU.
NG
4 Check continuity between terminals GND (A7 - 16, 19) of brake actuator connec-
tor and body ground.
CHECK:
Measure the resistance between terminal A7 - 16, 19 of brake
actuator harness side connector and body ground.
OK:
Resistance: 1 W or less
NG Repair or replace harness or connector.
OK
Check for open circuit in harness and connector between terminal IG1 of brake actuator
and ECU-IG fuse (See page IN-30).