1991 LEXUS SC300 key

TERMINALS OF ECU
 No. Symbol Terminal Name No. Symbol Terminal Name T8±3 ACT ± Door Lock Motor T8±13 DSWD Door Open Detection Switch 

T8±4
 

ACT +
 

Door Lock Motor
 

T8±14
 

L1
 

Door Key Lock and Unlock Switch
(Lock)
 

T8±5
 

TO
 

Luggage Compartment Door Opener
Motor 

T8±15
 

UL1
 

Door Key Lock and Unlock Switch
(Unlock)
 T8±6 KSW Key Unlock Warning Switch T8±16 E Ground 

T8±7 

LSWP 

Door Unlock Detection Switch 

T8±17 

L2 

Door Lock Control Switch (Lock)
 T8±8 + B2 Actuator Power Source T8±18 UL2 Door Lock Control Switch (Unlock)
 


T8±10 


UL3 


Door Key Lock and Unlock Switch
(Unlock) 


T8±19 


TSW 


Luggage Compartment Door Opener
Switch
 T8±11 LSWD Door Unlock Detection Switch T8±20 + B1 ECU Power Source
 T8±12 DSWP Door Open Detection Switch   
BE±368±
BODY ELECTRICAL SYSTEM Door Lock Control System
WhereEverybodyKnowsYourName

STANDARD VALUE OF ECU TERMINAL
 

Terminals 

Symbols 


Wiring
Color 

Condition 

Standard Value
 T9±3
e T9±4 ACT e ACT+ L±W e L±R Ignition switch OFF 50
or less
 T9±5 e T9±16 T0 e E B e W±B Ignition switch OFF 100
or less
 
T9 6 eT9 16
 
KSW eE
 
Ye WB
 Key unlock warning switch ON.
(Key is inserted into key cylinder). 1
or less
 


T9±6
e T9±16 


KSW
e E 


Y
e W±B 

Key unlock warning switch OFF.
(Key is not inserted into key cylinder). 

1 M

or higher
 

T9±7
e T9±16
 

LSWP
e E
 

P±B
e W±B
 


Door unlock detection switch ON.
(Passenger's) 

1

or less
    Door unlock detection switch OFF. 1 M
higher
 T9±8 e T9±16 +B2 e E L±W e W±B Always 10±14 V
 
T9 10 eT9 16
 
UL3 eE
 
Ge WB
 Door key lock and unlock switch ºunlockº
position. 1
or less
 


T9±10
e T9±16 


UL3
e E 


G
e W±B 

Door key lock and unlock switch OFF or
ºlockº position. 

1 M

or higher
 
T9 11 eT9 16
 
LSWD eE
 
WL eWB
 Door unlock detection switch ON. (driver's) 1
or less
 T9±11 e T9±16 LSWD e E W±L e W±B Door unlock detection switch OFF. (driver's) 1 M
or higher
 

T9 12
eT9 16
 

DSWP
eE
 

RW
eWB
 


Door open detection switch (passenger's)
ON (door opened). 

1

or less
 


T9±12
e T9±16 


DSWP
e E 


R±W
e W±B 


Door open detection switch (passenger's)
OFF (door closed). 


1 M

or higher
 
T9 13 eT9 16
 
DSWD eE
 
RB eWB
 Door open detection switch (driver's)
ON (door opened). 1
or less
 


T9±13
e T9±16 


DSWD
e E 


R±B
e W±B 

Door open detection switch (driver's)
OFF (Door closed). 

1 M

or higher
 

T9 14
eT9 16
 

L1
eE
 

GY
eWB
 


Door key lock and unlock switch ºlockº
position. 

1

or less
 


T9±14
e T9±16 


L1
e E 


G±Y
e W±B 


Door key lock and unlock switch OFF or
ºunlockº position. 


1 M

or higher
 
T9 15 eT9 16
 
UL1 eE
 
GW eWB
 Door key lock and unlock switch ºunlockº
position. 1
or less
 


T9±15
e T9±16 


UL1
e E 


G±W
e W±B 

Door key lock and unlock switch OFF or
ºlockº position. 

1 M

or higher
 


T9±16
e Body
Ground 


E
e Body
Ground 


W±B
e Body
Ground 

Always 

1

or less
    Door lock control switch ªlockº position. 1
or less
 

T9±17 e T9±16 

L2 e E 

R±B e W±B 

Door lock control switch OFF or ªunlockº
position. 

1 M
or higher
    Door lock control switch ªunlockº position 1
or less 

T9±18
e T9±16 

UL2
e E 

G±L
e W±B 

Door lock control switch OFF or ªlockº
position. 

1 M

or higher
±
BODY ELECTRICAL SYSTEM Door Lock Control SystemBE±369
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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:
If the instruction ªProceed 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.

If the trouble still reappears even though there are no abnormalities in a\
ny of the other circuits, then check
or replace the Theft Deterrent and Door Lock ECU as the last step.
See page
BE±376BE±378BE±380BE±382BE±384BE±386BE±388BE±390BE±392IN±32
SymptomSuspect Area
ECU Power Source CircuitActuator Power Source CircuitDoor Lock Motor CircuitLuggage Compartment Door Opener Motor
CircuitDoor Lock Control Switch CircuitDoor key Lock and Unlock Switch CircuitKey Unlock Warning Switch CircuitLuggage Compartment Door Opener Main
Switch and Opener Switch CircuitDoor Open Detection Switch CircuitTheft Deterrent and Door Lock ECU
Whole functions of the door lock control system does notWhole functions of the door lock control system does not
t12435operate.12435
All doors or some doors are not locked and unlocked with theAll doors or some doors are not locked and unlocked with the
Door Lock Control Switch and Key o
perated SwitchDoor Lock Control Switch and Key operated Switch.
(Luggage compartment door opener function normally oper3124(Luggage compartment door opener function normally oper-
t)
3124
ate.)
Doors cannot be locked or unlocked with the door lock con-Doors cannot be locked or unlocked with the door lock con
trol switch. (Doors lock and unlock normally with the key op-1234(yy
erated switch.)
1234
Doors are not locked or unlocked with the key operatedDoors are not locked or unlocked with the key o erated
switch. (Doors lock and unlock normally with the door lock12(y
control switch.)
12
Key confinementprevention function does not operateKey confinement prevention function does not operate.123y
Doors lock and unlock normally with the key o
perated switch123Doors lock and unlock normally with the key operated switch.
Luggage compartment door opener function does not oper-Luggage compartment door opener function does not oper-
t213ate.213
±
BODY ELECTRICAL SYSTEM Door Lock Control SystemBE±371
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Door Key Lock and Unlock Switch Circuit
CIRCUIT DESCRIPTION
The door key lock and unlock switch is built in the door key cylinder.
When the key is turned to the lock side, terminal 3 of the switch is grounde\
d and when the key is turned
to the unlock side, terminal 1 of the switch is grounded.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
OKOK NG NG
Check door key lock and unlock switch.
Check harness and connectors between ECU
and switch, switch and body ground
(See page IN±27). Replace door key lock and unlock
switch.
1
2
Proceed to next circuit inspection shown on
matrix chart (See page
BE±371). Repair or replace harness or
connector.
WIRING DIAGRAM
BE±386±
BODY ELECTRICAL SYSTEM Door Lock Control System
WhereEverybodyKnowsYourName

OKNG
OKNG
INSPECTION PROCEDURE
1Check door key lock and unlock switch.
C
OK
P1. Remove the door trim and service hole cover.
2. Disconnect the door ley lock and unlock switch con-
nector.
Check continuity between terminals 1, 2 and 3 of door
key lock and unlock switch is turned to the lock side, un-
lock side and not turned.
Replace door key lock and unlock switch.
2Check harness and connectors between ECU ans switch, switch and body ground (See page
IN±27 ).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on ma-
trix chart (See page BE±371).
±
BODY ELECTRICAL SYSTEM Door Lock Control SystemBE±387
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OKOK NG NG
Check key unlock warning switch.
Check harness and connectors between ECU and
key unlock warning switch, key unlock warning
switch and body ground (See page
IN±27).
Replace key unlock warning
switch.1
2
Proceed to next circuit inspection shown on
matrix chart (See page BE±371). Repair or replace harness or
connector.
WIRING DIAGRAM
Key Unlock Warning Switch Circuit
CIRCUIT DESCRIPTION
The key unlock warning switch goes on when the ignition key is inserted in the key cylinder and goes
off when the ignition key is removed.
The ECU operates the key confinement prevention function while the key unlo\
ck warning switch is on.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
BE±388±
BODY ELECTRICAL SYSTEM Door Lock Control System
WhereEverybodyKnowsYourName

OKNG
OKNG
INSPECTION PROCEDURE
1Check key unlock warning switch.
C
OK
PDisconnect key unlock warning switch connector.
Check continuity between terminal 9 and 10 of key un-
lock warning switch connector, when the key is inserted
to the key cylinder or removed.
Replace key unlock warning switch.
2Check harness and connectors between ECU and key unlock warning switch, key un\
lock warn-
ing switch and body ground (See page IN±27).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on ma-
trix chart (See page BE±371).
±
BODY ELECTRICAL SYSTEM Door Lock Control SystemBE±389
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