TOYOTA AVALON 2001 Service Repair Manual

F09478
1
3
4
1
2
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-289
445 Author
: Date
:
2001 AVALON (RM808U)
3 Check yaw rate sensor.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure the voltage between terminals IGA (3) and
GYW2 (1), YAW2 (4) and GYW2 (1) of the yaw rate sensor
with connector still connected.
OK:
Terminals 3 and 1
(IGA - GYW2)Approx. 12 V
Terminals 4 and 1
(YAW2 - GYW2)Approx. 2.5 V
NG Replace yaw rate sensor.
OK
4 Check for open and short circuit in harness and connector between yaw rate
sensor and ABS & BA & TRAC & VSC ECU (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace ABS & BA & TRAC & VSC
ECU.

F09814
J/B No. 3
15
3B 15
3AABS & BA & TRAC
& VSC ECU
40
A20
LBL Driver Side J/B
Engine Room J/B
M6
Multi
DisplayIC1 Translate
ECU
L-B 25
T5 11
T5
16
T5R-W
7
R-W
3
4
R-B LVL2LBL
BRL R-W
R-W
Level
Warning Switch12
1I 8
1H
R-W
12
BB J1
J/B
W-B
EDDriver Side J/B
GAUGE No. 1
W-B
W-B
J/B No. 4
10
1DR-B4
4D13
4F 4
2D4
2F
BRAKE
DI-290
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
446 Author
: Date
:
2001 AVALON (RM808U)
DTC C1202 / 44 Brake Fluid Level Warning Switch Cir-
cuit
CIRCUIT DESCRIPTION
The brake fluid level warning switch sends appropriate signals to the ECU when the brake fluid level is low-
ered.
HINT:
Depressing the parking brake pedal turns on the brake warning light, but this DTC No. C1202/44 is not out-
put.
DTC No.DTC Detecting ConditionTrouble Area
C1202 / 44
Fluid level in the brake master cylinder reservoir tank re-
mains low for 60 sec. or more. This means brake fluid
warning switch likes on.
Brake fluid level

Brake fluid level warning switch

Brake fluid level warning switch circuit
WIRING DIAGRAM
DI6O3-01

- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-291
447 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check brake fluid level.
CHECK:
Check the amount of fluid in the brake reservoir.
NG Check for fluid leakage, repair brake line and
add fluid.
OK
2 Check brake fluid level warning switch (See page BE-53).
NG Replace brake fluid level warning switch.
OK
3 Check for open circuit in all the harness and components connected to brake
fluid level warning light (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace ABS & BA & TRAC & VSC
ECU.

F09819
Translate ECU
SS2 SS1 RSS VSC- VSC+ T5
T5
T5
T5
T54
5
18 17
6W
O
BR
L
B-W
(Shielded)5
48
7 C11
Steering
Sensor
W-B R-B19 6
77
3B 3A 3A
3A(Shielded)
59
61
60
2 ABS & BA &
TRAC & VSC ECU
SS1
SS2
FSS
R+ A20
BR
GR-R
W-B
A
AJ5
J/C
W-B
IG J/B No. 3A20
A20
A20 DI-292
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
448 Author
: Date
:
DTC C1208 / 54 Steering Angle Sensor Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1208 / 54
Detection of any of conditions 1. through 7:
1. When the condition that ECU terminal IG1 voltage is 9.8
v or more, and does not receive data from steering angle
sensor continues for 0.1 sec. or more.
2. Sensor internal failure.
3. The offset value is out of range.
4. Sensor signal change higher.
5. Steering angle value difference between measured and
reference is out of range.
6. Steering sensor is not centered.
7. Steering sensor signal is out of range.

Steering angle sensor

Steering angle sensor circuit
WIRING DIAGRAM
DI6O4-01

- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-294
449 Author
: Date
:
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1 in case of using the TOYOTA hand-held tester and start from step 2 in case
of not using the TOYOTA hand-held tester.
1 Check output value of the steering angle sensor.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the TOYOTA hand-held tester main switch ON.
(c) Select the DATALIST mode on the TOYOTA hand-held tester.
CHECK:
Check that the steering wheel turning angle value of the steering angle sensor displayed on the TOYOTA
hand-held tester is appropriate when turning the steering wheel.
OK:
Steering wheel turning angle value must be appropriate.
OK Go to step 4.
NG
2 Check the installation condition of steering angle sensor and adapter.
NG Repair or replace steering angle sensor (See
page SR-12).
OK
3 Check for open and short circuit in harness and connector between steering
angle sensor, translate ECU and ABS & BA & TRAC & VSC ECU (See page
IN-30).
NG Repair or replace harness or connector.
OK

DI-294
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
450 Author
: Date
:
4 Calibrate the steering angle sensor (See page DI-252).
NG Replace steering angle sensor.
OK
5 Is DTC still output?
Check DTC on page DI-252.
NO No problem.
YES
6 Replace steering angle sensor. Is DTC still output?
NOTICE:
When replacing the steering angle sensor, perform the zero point calibration (See page DI-252).
NO No problem.
YES
Replace skid control ECU.
NOTICE:
When replacing the skid control ECU, perform the zero point calibration (See page DI-252).

- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-295
451 Author
: Date
:
2001 AVALON (RM808U)
DTCC1237 / 37 Wrong Number of Teeth at 1 of 4 Wheels
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1237 / 37
Detection of any of conditions from 1. through 4.:
1. When the ignition switch is ON, the speed difference
between the rear right and rear left wheels is 5 km/h
(3mph) or more (vehicle speed: 100 km/h (62 mph) or
less).
2. When the ignition switch is ON, the slip difference be-
tween the reference wheel and any other wheels is 6 %
or more (vehicle speed: 100 km/h (62 mph) or more).
3. Continuous ABS control for 60 sec. or more.
4. 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.

Tire size

Speed sensor rotor
INSPECTION PROCEDURE
1 Check tire size.
NG Replace tires so that all 4 tires are the same in
size.
OK
2 Check sensor rotor (See page DI-267).
NG Replace speed sensor rotor.
OK
3 Check speed sensor (See page DI-267).
NG Replace speed sensor.
OK
DI6O5-01

DI-296
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
452 Author
: Date
:
2001 AVALON (RM808U)
4 Check for open and short circuit in harness and connector between front speed
sensor, rear speed sensor and ABS & BA & TRAC & VSC ECU (See page
IN-30).
NG Repair or replace harness and connector.
OK
Check and replace ABS & BA & TRAC & VSC
ECU.

F09821
ABS & BA &
TRAC & VSC ECU
1
A20
IG1
IJ Engine Room R/B No. 5J/B No. 3
J9
J/C
FL MAIN
BatteryEngine Room J/B
Y-R
J/B No. 4
18
4A 18
4H
Y-R Y-R11
3F 2
3C Driver Side J/B
Ignition Switch
ALTGND2 IG1 RelayECU-IG
No. 2
W-R13
1B
3
1B 1
1G
4
1C1
2
4 3
4
IG1
AM1AM1
B-L 2 W-L7
IF1W-L
55 21
B
1
2H 1
2G
F8 F101 1
F61GND1 29
A20
28
A20 W-B
W-B
W-B A
J5
J/C
J4
J/C A
AB
B W-B
W-B
W-B
IG W-B
W-B
FL Block W
B
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-297
453 Author
: Date
:
2001 AVALON (RM808U)
DTC C1241 / 41 IG Power Source Circuit
CIRCUIT DESCRIPTION
This is the power source for the ECU, hence the brake actuators.
DTC No.DTC Detecting ConditionTrouble Area
C1241 / 41
At a vehicle speed of 6 km/h (4 mph) or more, the condition
that low battery voltage is 9.8 V or less (during non-opera-
tion of ABS control) or 9.4 V or less (during operation of
ABS control) and high battery voltage is more than 17.4 V,
continues for 0.5 sec. or more.

Battery

Charging system

Power source circuit
WIRING DIAGRAM
DI6O6-03

F07886
Driver Side J/B
ECU-IG
No. 2
DI-298
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
454 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check ECU-IG No. 2 fuse.
PREPARATION:
Remove the ECU-IG No. 2 fuse from the driver side J/B.
CHECK:
Check continuity of the 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