1991 LEXUS SC400 wiring

NG
OK
1
2
Proceed to next circuit inspection shown on
matrix chart (See page BE±371)
Check luggage compartment door opener
main switch and opener switch.
Check harness and connectors between ECU
and main switch, opener switch and body
ground (See page IN±27). Repair or replace harness or
connector.
NG
OK Replace luggage compartment door
opener main switch and/or opener
switch.
WIRING DIAGRAM
Luggage Compartment Door Opener Main Switch and
Opener Switch Circuit
CIRCUIT DESCRIPTION
The luggage compartment door opener main switch is off when it
is pushed in, and the luggage compartment door opener switch is
on when it is pulled.
The ECU energizes the luggage compartment door opener motor
only when the main switch and opener switch are on together.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
BE±390±
BODY ELECTRICAL SYSTEM Door Lock Control System
WhereEverybodyKnowsYourName

1
2
NG
OK
Proceed to next circuit inspection shown on
matrix chart (See page BE±371)
Check door open detection switch.
Check harness and connectors between ECU and
door open detection switch, door open detection
switch and body ground (See page
IN±27).
Repair or replace harness or
connector.
NG
OK Replace door open detection
switch.
WIRING DIAGRAM
Door Open Detection Switch Circuit
CIRCUIT DESCRIPTION
The door open detection switch is built in the door lock assembly. It is on when the door is open and
off when the door is closed.
DIAGNOSTIC CHART
BE±392±
BODY ELECTRICAL SYSTEM Door Lock Control System
WhereEverybodyKnowsYourName

DESCRIPTION
The wireless door lock control system is to lock and unlock all the doors a\
t a distance, transmitting a weak radio
wave from a transmitter contained in the master ignition key.
The weak radio wave (coded differently for each key) is sent to the receiver via the rear window defo\
gger wiring.
For the function of the component parts of this system, refer to the circui\
t description in circuit inspection.
PARTS LOCATION
BE±440±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName

DESCRIPTION
The wireless door lock control system is to lock and unlock all the door\
s at a distance, transmitting a weak radio
wave from a transmitter contained in the master ignition key.
The weak radio wave (coded differently for each key) is sent to the receiver via the rear window defo\
gger wiring.
For the function of the component parts of this system, refer to the circui\
t description in circuit inspection.
PARTS LOCATION
BE±440±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName

WIRING DIAGRAM
Check defogger wire (See page BE±173).NG
OK Repair defogger wire.
Replace antenna pinjack cable and
capacitor.1
INSPECTION OF ANTENNA CIRCUIT
Antenna Circuit
CIRCUIT DESCRIPTION
The antenna receives the electromagnetic wave emitted by the transmitter and sends i\
t to the wireless
door lock ECU.
DIAGNOSTIC CHART
HINT: Perform this inspection only when vehicle antenna is judged to be fault\
y in initial check type II.
BE±448
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName

(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:
w When replacing the ROM, always disconnect the
ECU connector first.
w 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
WhereEverybodyKnowsYourName

Terminals of ECU
WIRING DIAGRAM
No.SymbolTerminal NameNo.SymbolTerminal Name
W8±1+BPower SourceW8±6KSWKey Unlock Warning Switch
W8±2LSWD1Door Unlock Detection Switch LHW8±7EGround
W8±3LSWPDoor Unlock Detection Switch RHW8±8
W8±4UL1Door Key Lock and Unlock SwitchW8±9LSWD2Door Lock Motor LH
W8±5L1Door Key Lock and Unlock SwitchW8±10DSWDDoor Open Detection Switch
BE±452±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName

STANDARD VALUE OF ECU TERMINAL
 

Terminals
 

Symbols
 

Wiring
color 

Condition
 

Standard
Value
 

W8±1
eW8±7
 

+B1
eE
 

R±L
eW±B
 

Wireless door lock main switch ON 

10 ~ 14 V 


W8±1eW8±7 


+B1eE 


R±LeW±B 

Wireless door lock main switch OFF
 

Below 1 V
 W8±2
eBody LSWD1 eBody L±W eBody Door lock knob of driver's door LOCK 8 ~ 10 V
 
y
Ground 
y
Ground 
y
Ground Door lock knob of driver's door UNLOCK Below 1 V
 W8±3 eBody LSWP eBody P±B eBody Door lock knob of assistant's door LOCK 8 ~ 10 V
 
y
Ground 
y
Ground 
y
Ground Door lock knob of assistant's door UNLOCK Below 1 V
 


W8 4
eBody
 


UL1
eBody
 


GW
eBody
 


Turn ignition switch ON,
Key operate switch Left and Right UNLOCK 


Below 1 V 


W8±4
eBody
Ground 


UL1
eBody
Ground 


G±W
eBody
Ground 


Turn ignition switch ON
Key operate switch Left or Right UNLOCK 


Below 1 V
    Except above mention 8 ~ 10 V
 

W8±5
eBody
 

L1
eBody
 

G±Y
eBody
 

Turn ignition switch, ON
Key operate switch Right LOCK 

Below 1 V
 


y
Ground 


y
Ground 


y
Ground 

Turn ignition switch ON,
Except above mention 

8 ~ 10 V
 W8±6
eBody KSW eBody Ye Body Ignition key insert key cylinder Below 1 V 

y
Ground 

y
Ground 

y
Ground 
Ignition key pull out key cylinder 
10 ~ 14 V 

W8±7
eBody
Ground
 

E
e Body
Ground
 

W±B
eBody
Ground
 

Always
 

Below 1 V
 

W8±9
eBody
 

LSWD2
eBody
 

W±L
eBody
 

Door lock knob of driver's door LOCK
 

8 ~ 10 V
 
y
Ground 
y
Ground 
y
Ground Door lock knob of driver's door UNLOCK Below 1 V
    Door open detection switch Left and Right ON 
 W8±10
eBody DSWD eBody G±L eBody Door open detection switch Left or Right ON Below 1 V
 
y
Ground 
y
Ground 
y
Ground Door open detection switch Left or Right OFF 
    Door open detection switch Left and Right OFF 10 ~ 14 V
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±453
WhereEverybodyKnowsYourName