Lexus SC300 / Lexus SC400. Manual - part 194

PARTS REPLACEMENT

WIRELESS DOOR LOCK ECU REMOVAL
AND INSTALLATION

1. 

REMOVE WIRELESS DOOR LOCK ECU
(a)  Remove the rear seat.
(b)  Remove the RH quarter trim panel.
(c)  Disconnect the connectors.
(d)  Remove the ECU.

2. 

INSTALL WIRELESS DOOR LOCK ECU
For installation, follow the removal procedure in reverse.

WIRELESS DOOR LOCK ECU AND
TRANSMITTER REPLACEMENT

Disassembly and assembly of the wireless door lock ECU
and transmitter includes details of spare parts and replace-
ment procedure for defective parts found through trouble-
shooting.
Each part is a precision electronic component so handle with
care.
Destroy old ROM and transmitter to prevent reuse.

1. 

SPARE PARTS AND REPLACEMENT PROCEDURE FOR
MALFUNCTIONING PARTS
(For malfunctioning transmitter)
(a)  Prepare the new transmitter (with ROM).
(b)  Remove the ECU from the vehicle.
(c)  Remove the ROM from the ECU.
(d)  Install the new ROM into the ECU.
(e)  Install the ECU into the vehicle.
(f)  Check that door lock remote control operation works.
(g)  Cut the new key to the shape of the replaced key.

(For non–functioning battery)
(a)  Prepare new battery (with O–ring).
(b)  Remove battery and O–ring from transmitter.
(c)  Install new battery and O–ring into transmitter.

–

BODY ELECTRICAL SYSTEM

Wireless Door Lock Control System

BE–449

(For malfunctioning ECU)
(a)  Prepare the new ECU (without ROM).
(b)  Remove the ECU from the vehicle.
(c)  Remove the ROM from the ECU.
(d)  Install the ROM into the new ECU.
(e)  Install the new ECU into the vehicle.

2. 

REMOVAL OF ROM FROM ECU
(a)  Remove the cover from the hole for ROM insertion.
(b)  Using long nosed pliers, grasp the center of the print

board (ROM) and remove it.

NOTICE:

•

When replacing the ROM, always disconnect the
ECU connector first.

•

When removing the ROM, always grasp the board
and do not touch the IC parts or print wiring on the
board.

(c)  Insert the new print board (ROM) along the rails on both

sides and push it in with your finger until the terminal on
the end is completely inserted.

(d)  Install the cover to the hole for ROM insertion.

3. 

REPLACEMENT OF BATTERY FOR TRANSMITTER
(a)  Remove the screw from the transmitter.
(b)  Remove the cover.

BE–450

–

BODY ELECTRICAL SYSTEM

Wireless Door Lock Control System

(c)  Remove the O–ring and battery.
(d)  Set the new battery and O–ring into the transmitter.
(e)  Install the cover to the transmitter body taking care not

to twist or displace the O–ring.

(f)  Tighten the screw.

–

BODY ELECTRICAL SYSTEM

Wireless Door Lock Control System

BE–451

Terminals of ECU

WIRING DIAGRAM

No.

Symbol

Terminal Name

No.

Symbol

Terminal Name

W8–1

+B

Power Source

W8–6

KSW

Key Unlock Warning Switch

W8–2

LSWD1

Door Unlock Detection Switch LH

W8–7

E

Ground

W8–3

LSWP

Door Unlock Detection Switch RH

W8–8

W8–4

UL1

Door Key Lock and Unlock Switch

W8–9

LSWD2

Door Lock Motor LH

W8–5

L1

Door Key Lock and Unlock Switch

W8–10

DSWD

Door Open Detection Switch

BE–452

–

BODY ELECTRICAL SYSTEM

Wireless Door Lock Control System