LEXUS LS430 2003 Factory Repair Manual

SYSTEM INDEX
System NameSee Procedure
Front Power Seat Control SystemINITIALIZATION

Fig. 1: Locating Front Power Seat Control System Components (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 2: Locating Front Power Seat Control System Components (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 3: Locating Front Power Seat Control System Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Communication Table

Fig. 4: Communication Table
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.FRONT POWER SEAT CONTROL SYSTEM DESCRIPTION
The power seat is standard equipment for the front seats and optional equipment for the rear seats.
On the LS430, a memory system for the driver seat is provided as standard equipment.
2.FUNCTION OF MAIN COMPONENT
The following functions are available.
MAIN COMPONENT FUNCTION
ComponentsFunction
Seat slide motorReceives signal from driver seat ECU, motor operates, and driver side's
seat slides forward and rearward.
Seat reclining motorReceives signal from driver seat ECU, motor operates, and driver side's
seat reclines forward and rearward.
Seat cushion slide motorReceives signal from driver seat ECU, motor operates, and driver side's
seat cushion slides.
Seat front vertical motorReceives signal from driver seat ECU, motor operates, and driver side's
seat front vertical raises and lowers.
Seat rear vertical motorReceives signal from driver seat ECU, motor operates, and driver side's
seat rear vertical raises and lowers.
Seat lumbar support upper
motorReceives signal from driver seat ECU, motor operates, and driver side's
seat lumbar support upper can be adjusted.
Seat lumbar support lower
motorReceives signal from driver seat ECU, motor operates, and driver side's
seat lumbar support lower can be adjusted.
Seat headrest height motorReceives signal from driver seat ECU, motor operates, and driver side's

3.SYSTEM OPERATION
The front power seat's adjustment and position memory are shown in the chart below.
SYSTEM OPERATION
For the memory function, first, memory switch operation is transferred from the driver door ECU to the
driver seat ECU via the multiplex communication line. Then, either the seat position is recorded in
memory or a previously recorded seat position is recalled.
HINT:
Use this procedure to troubleshoot the front power seat control system with memory function.
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1.VEHICLE BROUGHT TO WORKSHOP
2.CUSTOMER PROBLEM ANALYSIS CHECK AND PROBLEM SYMPTOM CHECK (SEE
CUSTOMER PROBLEM ANALYSIS CHECK
)
3.CHECK COMMUNICATION FUNCTION OF LARGE-SCALE MULTIPLEX
COMMUNICATION SYSTEM (BEAN)
seat headrest raises and lowers.
Seat position sensorIs built in each seat adjuster and sends seat position data to driver seat
ECU so that it can detect seat positions at all times.
Seat control switchBased on switches operated, seat adjuster signals are input into driver seat
ECU and seat is adjusted accordingly. Lumbar support adjustments are
also done.
Set switch Memory switchWhen set switch and memory switch are pressed simultaneously, SET, 1, 2
or 3 switch is input to driver door ECU and driver side's seat position is
recorded. Then, when memory switch is pressed, SET, 1, 2 or 3 switch is
input to driver door ECU and driver side's seat position changes according
to memory.
Seat Adjustment FunctionDriverFront Passenger
Fore-and-Aft SlidePower and memoryPower
RecliningPower and memoryPower
Cushion SlidePower and memory-
Front Vertical HeightPower and memoryPower
Rear VerticalPower and memoryPower
Dual Lumbar SupportPower-
Single Lumbar Support-Manual
Headrest Fore-and-AftManualManual
Headrest HeightPower and memoryPower

a. Use the hand-held tester to check for normal function of the multiplex communication system.
1. (ECU not connected, communication line malfunctioning) Without code outputs, proceed to
A.
2. (ECU not connected, communication line malfunctioning) With code outputs, proceed to B.
B: Go to MULTIPLEX COMMUNICATION SYSTEM (SEE MULTIPLEX COMMUNICATION
SYSTEM )
A: Go to Next Step
4.(SEE PROBLEM SYMPTOMS TABLE
)
a. If the fault is not listed on the problem symptoms table, proceed to A.
b. If the fault is listed on the problem symptoms table, proceed to B.
B: Go to step 6
A: GO TO NEXT STEP
5.OVERALL ANALYSIS AND TROUBLESHOOTING
a. (SEE DATA LIST/ACTIVE TEST
)
1. Inspection with the hand-held tester (DATA LIST)
2. Inspection with the hand-held tester (ACTIVE TEST)
b. (SEE TERMINALS OF ECU
)
c. (SEE INSPECTION
)
6.ADJUST, REPAIR OR REPLACE
7.CONFIRMATION TEST
END

Fig. 5: Customer Problem Analysis Check Sheet
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
The following item can be customized.

Front power seat:
FRONT POWER SEAT - CUSTOMIZE PARAMETERS
1.INITIALIZE FRONT POWER SEAT CONTROL SYSTEM
a. The power seat ECU must be initialized under any of the following conditions.
The battery is disconnected.
The D/C cut fuse is replaced.
The power seat switch (power seat ECU) is replaced.
The power seat assy is removed from the vehicle.
b. Initialize the power seat ECU as follows.
1. Using the seat switches, fully slide the seat forward, fully recline the seatback forward, and
fully raise the seat cushion and headrest.
2. Using the seat switches, fully slide the seat rearward, fully recline the seatback rearward, and
fully lower the seat cushion and headrest.
Display (Item)DefaultContentsSetting
HEADREST CONTROLAVAILFunction that activates
physique compensation
headrest control when driver
seat is moved (sliding).NOT AVL/AVAIL

Fig. 6: Problem Symptoms Table
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.