2001 TOYOTA AVALON Service Repair Manual

I13613
Cruise Control ECU
14
OD
6
ECT
G-Y
S2ECT No.2 SolenoidII221
B
6 ECM
GR OD1
S2E7
E6 24
1
G-Y G-YB
B
E1
C15
J8
J/C
G-Y
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-581
737 Author
: Date
:
2001 AVALON (RM808U)
Electronically Controlled Transmission Communication Circuit
CIRCUIT DESCRIPTION
When driving uphill under the cruise control, in order to reduce shifting due to ON-OFF overdrive operation
and to provide smooth driving, when down shifting in the electronically controlled transmission occurs, a sig-
nal to prevent upshift until the end of the uphill slope is sent from the cruise control ECU to the electronically
controlled transmission.
Terminal ECT of the cruise control ECU detects the shift change signal (output to electronically controlled
transmission No. 2 solenoid) from the ECM.
If the vehicle speeds down, also when terminal ECT of the cruise control ECU receives down shifting signal,
it sends a signal from terminal OD to ECM to cut overdrive until the end of the uphill slope, and the gear shifts
are reduced and gear shift points in the electronically controlled transmission are changed.
WIRING DIAGRAM
DI08U-13

AB0119
I00143
I00174
ON
O/D
(-) (+)
DI-582
- DIAGNOSTICSCRUISE CONTROL SYSTEM
738 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check operation of overdrive.
PREPARATION:
Test drive after engine warms up.
CHECK:
Check that overdrive ON e OFF occurs by operation of OD switch ON-OFF.
NG Check and repair electronically controlled
transmission (See page DI-158).
OK
2 Check voltage between terminal OD of harness side connector of cruise control
ECU and body ground.
PREPARATION:
(a) Remove the ECU with connector still connected.
(b) Turn ignition switch ON.
(c) Disconnect the ECU connector.
CHECK:
Measure voltage between terminal OD of harness side connec-
tor of ECU and body ground.
OK:
Voltage: 10 - 14 V
NG Go to step 5.
OK

I00141
ECT
(-) (+)
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-583
739 Author
: Date
:
2001 AVALON (RM808U)
3 Check voltage between terminal ECT of cruise control ECU connector and body
ground (On test drive).
PREPARATION:
(a) Connect the ECU connector.
(b) Test drive after engine warms up.
CHECK:
Check voltage between terminal ECT of ECU connector and
body ground when OD switch is ON and OFF.
OK:
OD switch positionVoltage
ON8 - 14 V
OFFBelow 0.5 V
OK Proceed to next circuit inspection shown in
problem symptom table (See page DI-560).
NG
4 Check harness and connector between terminal ECT of cruise control ECU and
electronically controlled transmission solenoid (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU.
5 Check harness and connector between terminal OD of cruise control ECU and
terminal OD1 of ECM (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU (See
page IN-30).

I17550
Cruise Control ECU
D 3
W-B 2
Ignition Switch1 II1
1G
3
4 4
2 1C
1
F10
1
ALT FL Block
1
FL MAINBattery IG1AM1CCS
F6 F8W-L26
1 20
AM1 Y-RY-R
R-L
R-LR-L
R-Y23
3D20
3C20
3C7
R-LY-R 4C6
4C19
II14
10 DL 2
W-R W
4
27
IF15
5 2
1
1 1
2H
2G
B-L1C1
1B3
IG B IG1 Relay
GAUGE NO. 2 A/T Indicator Light
Translate ECU
*1: w/ Traction Control
*2: w/o Tranction Control*1*2
T5
P1C15
I15
W-L
D6
DiodeY-R
*3: Floor Shift
*4: Column ShiftJ/B No. 4
J/B No. 3
*4
*3
Driver Side J/B
Engine Room R/B No. 5
BEngine Room J/B DI-584
- DIAGNOSTICSCRUISE CONTROL SYSTEM
740 Author
: Date
:
2001 AVALON (RM808U)
Park/Neutral Position Switch Circuit
CIRCUIT DESCRIPTION
When the shift position is except D, a signal is sent from the park/neutral position switch to the ECU. When
this signal is input during cruise control driving, the ECU cancels the cruise control.
WIRING DIAGRAM
DI08V-15

Input SignalIndicator Light
Blinking Pattern
Turn PNP switch
OFF (Shift to posi-
tions except D )LightON
OFFSW ON
SW OFF
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-585
741 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check starter operation.
CHECK:
Check that the starter operates normally and that the engine starts.
NG Proceed to engine troubleshooting.
OK
2 Input signal check.
PREPARATION:
See input signal check on page DI-551.
CHECK:
Check the indicator light when shifting into positions except D.
OK:
The indicator light goes off when shifting into posi-
tions except D.
OK Proceed to next circuit inspection shown in
problem symptom table (See page DI-560).
NG

AB0119
I00139
I00175
ON
D
(-) (+)
DI-586
- DIAGNOSTICSCRUISE CONTROL SYSTEM
742 Author
: Date
:
2001 AVALON (RM808U)
3 Check voltage between terminal D of cruise control ECU connector and body
ground.
PREPARATION:
Turn ignition switch ON.
CHECK:
Measure voltage between terminal D of ECU connector and
body ground when shifting into D position and other positions.
OK:
Shift PositionVoltage
D position10 - 14 V
Other positionsBelow 1 V
OK Proceed to next circuit inspection shown in
problem symptom table (See page DI-560).
NG
4 Check harness and connector between cruise control ECU and park/neutral
position switch (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU (See
page IN-30).

I13608
Cruise Control ECU
2
STP
G-W
R3
3C 1B
1
4Stop Light Switch
2
95
FL BlockC15
C15 3
II1
BatterySTOP
W
B 1D33
3D
P-B
W-B
IJ AJ9 J/C W-BP-BG-B8
L F61
F101
ALT
FL MAIN1D11
1G1
II1 13
43
C4
Cruise Control Actuator
S4 Stop Light Switch
S4J/B No. 3
Driver Side J/B Driver Side J/B
G-W
G-W DI-578
- DIAGNOSTICSCRUISE CONTROL SYSTEM
734 Author
: Date
:
2001 AVALON (RM808U)
Stop Light Switch Circuit
CIRCUIT DESCRIPTION
When the brake pedal is depressed, the stop light switch sends a signal to the ECU. When the ECU receives
this signal, it cancels the cruise control.
A fail-safe function is provided so that the cancel functions normally, even if there is a malfunction in the stop
light signal circuit.
The cancel conditions are: Battery positive voltage at terminal STP-
When the brake is ON, battery positive voltage normally is applied through the STOP fuse and stop light
switch to terminal STP- of the ECU, and the ECU turns the cruise control OFF.
If the harness connected to terminal STP- has an open circuit, terminal STP- will have battery positive volt-
age and the cruise control will be turned OFF.
Also, when the brake is ON, the magnetic clutch circuit is cut mechanically by the stop light switch, turning
the cruise control OFF. (See page DI-563 for operation of the magnetic clutch)
WIRING DIAGRAM
DI08T-17

Input SignalIndicator Light
Blinking Pattern
Stop Light
switch ON
LightOFF
ONSW OFF
SW ON
- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-579
735 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check operation of stop light.
CHECK:
Check that stop light comes ON when brake pedal is depressed, and turns OFF when brake pedal is re-
leased.
NG Check stop light system (See page BE-2).
OK
2 Input signal check.
CHECK:
(a) See input signal check on DI-551.
(b) Check the indicator light when the brake pedal is de-
pressed.
OK:
The indicator light goes OFF when the brake pedal is
depressed.
OK Proceed to next circuit inspection shown in
problem symptom table (See page DI-560).
NG