1991 LEXUS SC300 key

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

CUSTOMER PROBLEM ANALYSIS CHECK SHEET
\
 
\

\
WIRELESS DOOR LOCK CONTROL System Check Sheet
Inspector 's
Name:
 


 


 

Registration No.
 


 Customer 's Name  Registration Year //
 


 


 

Frame No.
 


 


Date Vehicle
Brought In 

// 

Odometer Reading 


Km
Miles
 Date of Problem Occurrence\
 \
//
 

Frequency of Problem Occurrence
\
 
\

\

Constant  Sometimes ( times/per day, month)
 Once Only
 


Conditions at
 

Weather
\
 
\

\


Fine  Cloudy  Rainy  Snowy
 Various/Others
 


Conditions at
Time of Problem
Occurrence 

Outdoor Temperature
\
 
\

\


Hot  Warm  Cool
 Cold (Approx. 5F( 5C))
 


 

Place\
 
\

\

Everywhere  Specific Locality ( )
 

Date Transmitter Battery Last Replaced\
 
\

\
//
 \
 \

Whole wireless door lock control system does not operate
\

Whole wireless door lock control system does not operate.
 


\
 
\

\

Only door unlock operation is not possible.
 \
 \
Only door lock operation is not possible.
 


\
 
\

\

Only key confine prevention function is not possible.
 \
 \
 Wireless door lock function operates even when each door is opened.
 




\
 
\


\

\


Wireless door lock function incorrectly.
(Although one door is unlocked, when the transmitter
switch is pressed, all doors unlock.)
 





When RH door is unlocked.
 When LH door is unlocked.
 








\
 
\


\


\


\

\


Others
Problem Symptom
BE±444±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName

PRECHECK TYPE I
In cases where the wireless door lock control system fails to operate only\
at a specific locality, perform this check
at that locality.
Open the driver's door
(Other doors remain closed).Using the door lock control switch, perform
ªlock, unlockº
*1 operation 10 times within 30
seconds.
How many times in 10 seconds is ªlock, un-
lockº
*1 operation performed automatically by
the ECU?
Noise is being produced at that locality.
*3
Vehicle is now receiving signals from a
transmitter of another vehicle (during
transmission from transmitter of another
vehicle).
Malfunction on vehicle side
(Proceed to Matrix Chart of Problem
Symptom on page
BE±454).
Does not
operate
2 times
3 times
Normal
*2
*1: Performing lock and unlock once counts as one time.
*2: If noise is not constantly produced at the locality being used and inspect\
ion is performed on an occasion when there is no noise, then it may happen that the system is judged normal.\
*3: If the conclusion is that noise is produced in the locality the vehicle is\
used, then transmitter use is limited in that locality. Limitations on usage are described below.
HINT:
Because the transmitter uses weak electromagnetic waves, it is easily affected by noise, so remote control with-
in the normal range becomes difficult.
To reduce the influence of noise, bring the transmitter as close as possib\
le to the back window glass (antenna
section), or touch (ground) the grooved key tip of the transmitter to\
the door key cylinder and then operate the
transmitter switch; this should make door lock remote control operation possible.
If door lock remote control operation is still not possible, insert the \
key in the door key cylinder and press the
transmitter switch.
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±445
WhereEverybodyKnowsYourName

Open the driver's door
(Other doors remain closed).
Using the door lock control switch, perform
ªlock, unlockº
*1 operation 10 times with in
30 seconds.
Soon (less than 2 secs.) after performing
the above, continue to press the transmitter
switch for 10 seconds. How many times does ªlock, unlockº *1 op-
eration of all doors occur during the time the
transmitter is operated (approx. 10 secs.)? Malfunction on vehicle side
(Proceed to Matrix Chart of Problem
Symptom on page
BE±454).
Wrong transmitter parts (exclusive code
does not match).
[Replace transmitter and ROM in ECU.
(See page BE±449)]
Transmitter fault
(Inspect transmitter on page BE±447).
Close all doors.
Tune the FM radio to 94.9 MHz.
Inspect transmitter (See page BE±447).
Do all doors lock and unlock?
Is there noise on the radio while the trans-
mitter switch is being pushed? *2 Malfunction on antenna curcuit
(Inspect antenna circuit on page
BE±448).
Malfunction on vehicle side
(Proceed to Matrix Chart of Problem
Symptom on page BE±454).
3 times
2 timesDoes not
operate
YESYES
NO
NO Once

Disconnect the antenna cable from the ECU, directly insert
the transmitter (grooved section of key) and press the trans-
mitter switch. In this case do not let the transmitter come in
contact with the ECU case (because the transmitter will be
grounded).
PRECHECK TYPE II
Perform this check in cases where the wireless door lock control system fails t\
o operate anywhere.
*1: Performing lock and unlock once counts as one time.
*2: In some localities, inspection cannot be carried out because the local FM \
radio broadcast is also at 94.9 MHz. When this occurs, perform inspection using a portable radio in a place \
indoors free from the influence
of FM broadcasts.
BE±446
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName

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 SystemBE±449
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

MATRIX CHART OF PROBLEM SYMPTOMS
Perform troubleshooting of the circuits for the applicable problem symptom in t\
he order given in the chart below.
Proceed to the page located for each circuit.
HINT:
w Troubleshooting of the wireless door lock control system is based on the premise that the d\
oor lock
control system is operating normally. Accordingly, before troubleshooting the wireless door lock
control system, first make certain that the door lock control system is \
operating normally.
w If the instruction ºProceed to next circuit inspection shown on matrix \
chartº is given in the flow chart for each
circuit, proceed to the circuit with the next highest number in the table to con\
tinue the check.
w If the trouble still reappears even though there are no abnormalities in a\
ny of the other circuits, then check
and replace the Wireless Door Lock ECU as the last step.
See page
BE±460BE±462BE±464BE±466BE±468BE±470IN±32
SymptomSuspect
Area
ECU Power Source CircuitDoor Unlock Detection Switch CircuitDoor Key Lock and Unlock Swtich Circuit
(Unlock Side)Door Key Lock and Unlock Swtich Circuit
(Lock Side)Key Unlock Warning Switch CircuitDoor Open Detection Swtich CircuitWireless Door Lock ECU
All functions of wireless door lock control system do not
operate.134526
Only door unlock operation is not possible
(Lock operation is possible).213
Only door lock operation is not possible
(Unlock operation is possible).12
Only transmitter misoperation prevention function is not
possible12
Wireless door lock function operates even when each door is
opened.12
Wireless door lock functions incorrectly.
(Although one door is unlocked, when the transmitter switch
is pressed, all doors unlock.)
12
BE±454±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName