2001 TOYOTA AVALON Service Repair Manual

DI-512- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
668 Author
: Date
:
2001 AVALON (RM808U)
Driver 's seat reclining switch:
Switch positionTester connectionSpecified condition
FORWARD1 - 3Continuity
REAR1 - 2Continuity
Passenger 's slide switch:
Switch positionTester connectionSpecified condition
FRONT1 - 9Continuity
BACK1 - 6Continuity
Passenger 's front vertical switch:
Switch positionTester connectionSpecified condition
UP1 - 10Continuity
DOWN1 - 5Continuity
Passenger 's lifter switch:
Switch positionTester connectionSpecified condition
UP1 - 7Continuity
DOWN1 - 8Continuity
Passenger 's reclining switch:
Switch positionTester connectionSpecified condition
FORWARD1 - 3Continuity
REAR1 - 2Continuity
NG Replace power seat control switch.
OK
3 Check harness and connectors between Seat Position Control ECU and power
seat control switch (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace Seat Position Control
ECU.

I13621
Seat Memory SwitchPower Seat ECU
SWE SW2
MMRY 21
320
9SW1
7 1 4
2
P21 P21 P21
P21
2
1
MMRY
EY
G-W
G-Y
W-B
S14
I11616
(+)
(-)9 (MMRY)
19 (SGND)
20 (SW2) 21 (SW1)
- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI-513
669 Author
: Date
:
2001 AVALON (RM808U)
Seat Memory Switch
CIRCUIT DESCRIPTION
Seat memory switch send memory and return signals to the seat position control ECU.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between each terminal of the seat memory switch and SGND of
Seat Position Control ECU connector.
PREPARATION:
Remove Seat Position Control ECU with connectors still con-
nected.
CHECK:
Measure voltage between terminal of the seat memory switch
and SGND of Seat Position Control ECU connector.
(The illustration shows inspection of the Memory 1 as an exam-
ple.)
OK:
At each terminal with switch ON0 V
At each terminal with switch OFF10 ~ 14 V
OK Proceed to next circuit inspection shown in
problem symptom table (See page DI-493).
DI0GH-06

N21463
(Example)
Inspection of SET Switch
2
1
DI-514- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
670 Author
: Date
:
2001 AVALON (RM808U)
NG
2 Check seat memory switch.
PREPARATION:
Disconnect seat memory switch connector.
CHECK:
Check continuity of each terminal.
OK:
Switch positionTerminal
SET switch ON1 - 2
Memory switch 12 - 3
Memory switch 22 - 4
NG Replace seat memory switch.
OK
3 Check harness and connectors between Seat Position Control ECU and seat
memory switch (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace Seat Position Control
ECU.

DI0FR-06
POWER SEAT CONTROL SYSTEM Check Sheet
Inspector 's name:
Customer 's Name
Date of VehicleRegistration No.
Registration Year
Frame No.
Odometer Reading / /km
Mile
How Often Problem Occurs
/ /

Continuous
Intermittent ( Times a day) Brought in

Manual Function
does not operate.
Slide
Front Vertical
Rear Vertical
Reclining

Memory function does not operate.

Position return function does not stop when brake pedal is depressed.
Date Problem First Occurred
Problem Symptom

Slide
Front Vertical
Rear Vertical

Does not operate in any conditions

Only with key inserted

Only with key not inserted

Only with memory & return switch 1 or 2
Return Function
does not operate.
- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI-489
645 Author
: Date
:
2001 AVALON (RM808U)
CUSTOMER PROBLEM ANALYSIS CHECK

DI0FP-07
Customer Problem Analysis
Vehicle Brought to Workshop
Problem Symptom ConfirmationSymptom Simulation Symptom does not occur
Problem Symptom Table
Circuit Inspection
Identification of Problem
Repair
Confirmation Test
EndTitles inside
are titles of pages in this
manual with the page number indicated in the
bottom portion. See the indicated pages
for detailed explanations. 1
23
4
5
7P. DI-489
P. DI-493
P. IN-20
P. DI-494 - DI-513
Symptom occur
6
Parts Inspection
Step 5, 7 : Diagnostic steps permitting the use
of the hand-held tester and break-
out-box.
DI-488- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
644 Author
: Date
:
2001 AVALON (RM808U)
POWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
HOW TO PROCEED WITH TROUBLESHOOTING
Perform troubleshooting in accordance with the procedure on the following page.

DI0FT-05
I12537Front Vertical MotorEngine Room Junction Block

ECU-B NO. 1 Fuse
Instrument Panel Junction Block

PWR SEAT M-Fuse
Reclining Motor
Power Seat Control ECU
Rear Vertical
Motor
Slide MotorLumbar Support Switch
Seat Memory Switch
Power Seat Control Switch DI-490
- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
646 Author
: Date
:
2001 AVALON (RM808U)
PARTS LOCATION

DI0FV-08
- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI-493
649 Author
: Date
:
2001 AVALON (RM808U)
PROBLEM SYMPTOMS TABLE
Perform troubleshooting of the circuits for the applicable problem symptom in the order given in the chart
below. Proceed to the page located for each circuit.
HINT:

If the instruction ºProceed to next circuit inspection shown on problem symptom tableº is given in the
flow chart for each circuit, proceed to the circuit with the next highest number in the table to continue
the check.

If the trouble still reappears even though there are no abnormalities in any of the other circuits, then
check and replace the Seat Position Control ECU as the last step.
SymptomSuspect AreaSee page
Both manual & return functions do not operate(All functions).
3. +B power source circuit
4. Power seat control switch circuit
5. Motor circuit
6. Power seat control ECUDI-494
DI-510
DI-500
IN-30
Both manual & return functions do not operate(One function only).1. Motor circuit
2. Power seat control ECUDI-500
IN-30
One or all functions do not operate for manual operation only.1. Power seat control switch circuit
2. Power seat control ECUDI-510
IN-30
Memory function does not operate.
1. Power seat memory switch circuit
2. Ignition switch circuit
3. Power seat control ECUDI-510
DI-508
IN-30
Return operation does not stop when brake pedal is depressed.1. Stop light switch circuit
2. Power seat control ECUDI-662
IN-30
Only return function does not operate or operates a little, then
stops (All return functions).
1. Power seat memory switch circuit
2. ECU power source circuit
3. Position sensor power source circuit
4. Power seat control ECUDI-513
DI-497
DI-504
IN-30
Only return function does not operate or operates a little, then
stops (Only one return function).1. Position sensor circuit
2. Power seat control ECUDI-506
IN-30

DI6KY-01
I11581
P20P21
- DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI-491
647 Author
: Date
:
2001 AVALON (RM808U)
TERMINALS OF ECU
Symbols (Terminals No.)Wiring ColorConditionSTD Voltage (V)
SSFV e SGND
(P21-4 e P21-19)L-B e BRFront vertical operation0 V e 8 V
SSRL e SGND
(P21-17 e P21-19)L-W e BRRear vertical operation0 V e 8 V
SSRR e SGND
(P21-16e P21-19)L-R e BRReclining operation0 V e 8 V
PVCC e SGND
(P21-5 e P21-19)R e BRPower seat operation8 V
FDWN e Body Ground RBSeat lowered using front vertical SWBelow 1 VFDWN e Body Ground
(P21-24 eBody Ground)R-BOthers10 - 14 V
IG e Body Ground
(P21-13 eBody Ground)R-BIgnition SW ON10 - 14 V
SYSB e Body Ground
(P21-25 eBody Ground)W-GAlways10 - 14 V
MPX1Bd G dMultiplex communication circuit signals0 V e 12 VMPX1 e Body Ground
(P21-14 eBody Ground)G-WOthersResistance
(Approx. 2.5 kW)
SGND e Body Ground
(P21-19 eBody Ground)BRAlwaysBelow 1 V
SSRS e SGND
(P21-3 eP21-19)L e BRSlide operation0 V e 8 V
SLDF e Body Ground BSeat moved forward using slide SWBelow 1 VSLDF e Body Ground
(P21-6 eBody Ground)BOthers10 - 14 V
SLDR e Body Ground BRSeat moved to rear using slide SWBelow 1 VSLDR e Body Ground
(P21-8 eBody Ground)B-ROthers10 - 14 V
LUP e Body Ground RWSeat raised using rear vertical SWBelow 1 VLUP e Body Ground
(P21-22 eBody Ground)R-WOthers10 - 14 V
LDWN e Body Ground RYSeat lowered using rear vertical SWBelow 1 VLDWN e Body Ground
(P21-1 1 eBody Ground)R-YOthers10 - 14 V
FUP e Body Ground BYSeat raised using front vertical SWBelow 1 VFUP e Body Ground
(P21-23 eBody Ground)B-YOthers10 - 14 V
RCLF e Body Ground GBSeat moved forward using reclining SWBelow 1 VRCLF e Body Ground
(P21-10 eBody Ground)G-BOthers10 - 14 V
RCLR e Body Ground GSeat moved to rear using reclining SWBelow 1 VRCLR e Body Ground
(P21-12 eBody Ground)GOthers10 - 14 V
RCL- e GND RBWBSeat moved to rear using reclining SW10 - 14 VRCL e GND
(P20-1 e P20-7)R-B e W-BOthersBelow 1 V