2001 TOYOTA AVALON Service Repair Manual

F00064
LOCK
16(+)(-) LOCK
(+)(-)LOCK
19 1817
(+)(-) A7
DI-222- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)
378 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check voltage between terminals +B (A7 - 17, 18) and GND (A7 - 16, 19) of brake
actuator connector.
PREPARATION:
Disconnect the connector from the brake actuator.
CHECK:
Measure the voltage between terminals A7 - 17, 18 and A7 -
16, 19 of brake actuator harness side connector.
OK:
Voltage: 10 - 14 V
NG Check and replace fuses.
Check and repair harness or connector.
OK
If the same code is still output after the DTC is deleted, check the contact condition of each con-
nection. If the connections are normal, the ECU may be defective.

F09803
ABS Actuator and ECU
+B
BAT
GND1
GND2 W-B
FL MAINFL Block
ALT
B-L
BatteryA717
A718
A719
A716 L
L
W-B
EE5 5
12 B
10 2F
42F 12H
12G
W-B
ED 1
F8 1
F6
BABS Engine Room R/B No. 5
Engine Room J/B
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM WITH ELECTRONIC
BRAKE FORCE DISTRIBUTION (EBD)DI-223
379 Author
: Date
:
2001 AVALON (RM808U)
DTC 21 - 24 ABS 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
21, 22, 23, 24Solenoid signal does not match the check result.
Brake actuator

Each solenoid circuit
WIRING DIAGRAM
DI6NE-01

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.

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

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

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

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

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.