Page 679 of 1897

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
Page 681 of 1897
F07895
ON
(+) (-) 128
29
F07896
(+)
(-) LOCK
2928
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-299
455 Author: Date:
2001 AVALON (RM808U)
3 Check voltage between terminals IG1 (1) and GND (28, 29) of ABS & BA & TRAC
& VSC ECU.
PREPARATION:
Disconnect the connector from the ABS & BA & TRAC & VSC
ECU.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure the voltage between terminals 1 and 28, 29 of
ABS & BA & TRAC & VSC ECU harness side connector.
OK:
Voltage: 10 - 14 V
OK Check and replace ABS & BA & TRAC & VSC
ECU.
NG
4 Check continuity between terminals GND (28, 29) of ABS & BA & TRAC & VSC
ECU and body ground.
CHECK:
Measure the resistance between terminal 28, 29 of ABS & BA
& TRAC & VSC ECU 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 ABS & BA & TRAC & VSC ECU and
ECU-IG fuse (See page IN-30).
Page 683 of 1897

F07902
PMCE2
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-301
457 Author: Date:
2001 AVALON (RM808U)
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 master cylinder pressure 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 brake fluid pressure value of the master cylinder pressure sensor displayed on the TOYOTA
hand-held tester is changing when depressing the brake pedal.
OK:
Brake fluid pressure value must be changing.
OK Go to step 4.
NG
2 Check master cylinder pressure sensor.
PREPARATION:
Install LSPV gauge to the front caliper bleeder plug portion, and
bleed the air from LSPV gauge.
SST 09709-29018
CHECK:
Start the engine and depress the brake pedal, then check the
relation between the fluid pressure and voltage of PMC and E2
terminals of the master cylinder pressure sensor with connector
still connected.
OK:
Front brake caliper fluid pressureVoltage
0 kPa (0 Kgf/cm2, 0 psi)0.44 - 0.76 V
5,883 kPa (60 kgf/cm2, 853 psi)1.34 - 1.66 V
11,768 kPa (120 kgf/cm2, 1,706 psi)2.24 - 2.56 V
HINT:
Voltage between terminals VCM and E2: 4.7 - 5.3 V
NG Replace master cylinder pressure sensor.
OK
Page 685 of 1897
F09817
ABS & BA & TRAC
& VSC ECU
48
A20
STP
ALTJ/B No. 3
FL Block
FL MAIN
Battery Driver Side J/B
S4
Stop Light SwitchG-W
STOP
L5
Light Failure SensorR8
Rear Combination
Light RH
G-R
J12
J/C J/B No. 4
16
4D 16
4F 3
3F 3
3C 5
1B 3
1D
4 1E
5IK1
7 12R
Driver Side J/B
11
1D 1
1G W
1
F101
F6B2
G-R W-B BB
B3
6
C Stop R7
Rear Combination
Light LH
3
6 Stop
1 R-W
W-B H11
High Mounted
Stop Light
21
C
C
W-B
BM G-R W-B G-W G-W
G-W
G-W
G-W
J12
J/C
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-303
459 Author: Date:
2001 AVALON (RM808U)
DTC C1249 / 58 Stop Light Switch Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1249 / 58
After the ignition switch is turned ON, the condition that the
STP terminal voltage of ECU is 55 % to 75 % of supplied
voltage, continues for 1 sec. or more.Stop light switch
Stop light switch circuit
WIRING DIAGRAM
DI6O8-03
Page 690 of 1897
F09810
ABS & BA &
TRAC & VSC ECU
ML- ML+
A622
24
A20 A20
IE1 Precharge Pump
V
VW-R
W-R
IE18
9 A61
6
ML- ML+
ML- ML+ Brake Actuator
1 2 DI-308
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
464 Author: Date:
2001 AVALON (RM808U)
DTC C1351 / 52Precharge Pump Motor Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1351 / 52
When any of the following 1. or 2. is detected:
1. After the ignition switch is turned ON, an open or short
circuit continues for 0.06 sec. or more.
2. The precharge pump motor voltage is out of range when
precharge pump if off.
Precharge pump motor
Precharge pump motor circuit
WIRING DIAGRAM
DI6OB-02
Page 691 of 1897

F07901
2 1
(-)(+)
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-309
465 Author: Date:
2001 AVALON (RM808U)
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 TOYOTA hand-held tester.
1 Check precharge pump motor operation.
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 ACTIVE TEST mode on the TOYOTA hand-held tester.
CHECK:
Check the operation sound of the precharge pump motor when operating it with the TOYOTA hand-held
tester.
OK:
The operation sound of the precharge pump motor should be heard.
NG Go to step 3.
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.
2 Check precharge pump motor operation.
PREPARATION:
Disconnect the connector from the precharge pump motor.
CHECK:
Connect ML+ (2) terminal to the battery positive (+) and ML- (1)
terminal to the battery negative (-).
OK:
The operation sound of the pump motor should be
heard.
NG Check and replace precharge pump.
OK
Page 696 of 1897
F09477
ON
NEO
13
F03007
(Reference)
3 - 6 V
Below 1 V
DI-314
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
470 Author: Date:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check for open and short circuit in harness and connector between terminal
NEO of translate ECU and terminal NEO of ECM (See page IN-30).
NG Repair or replace harness and connector.
OK
2 Check voltage between terminal NEO (13) of translate ECU and body ground.
PREPARATION:
Remove the translate ECU with connectors still connected.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure the voltage between terminal 13 of the translate
ECU and body ground under the engine conditions below.
OK:
Engine conditionVoltage
OFF (IG ON)3 - 6 V or below 1 V
ON (Idling)3 - 6 V e below 1 V (Pulse)
NG Check and replace ECM.
OK
Check and replace transrate ECU.
If the same code is still output after the DTC is deleted, check the contact condition of each con-
nection.
Page 702 of 1897
F09822
ABS & BA &
TRAC & VSC ECU
IND A2031
V V18
IL1 M6 M69
4SLIP
R-B J/B No. 4
4D
4F 413
R-B
Driver Side J/B
1G1
1D10
1B1C 3 41 2IG1 Relay GAUGE
No. 1
W
W-R
2
IG1
AM1 4Ignition Switch
IF17
W-L
551
2 AM1 Engine Room R/B No. 5
B
2G
2H1 1 Engine Room J/B
B-L
F6 1 F10 F81
1
ALT FL Block
IG
Battery
FL MAIN
B Multi Display
4 3
W-BW-L
- DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI-333
489 Author: Date:
2001 AVALON (RM808U)
SLIP Indicator Light Circuit
CIRCUIT DESCRIPTION
The SLIP indicator light blinks during TRAC & VSC operation.
WIRING DIAGRAM
DI6OL-03