lock LEXUS SC400 1991 Service Repair Manual
[x] Cancel search | Manufacturer: LEXUS, Model Year: 1991, Model line: SC400, Model: LEXUS SC400 1991Pages: 4087, PDF Size: 75.75 MB
Page 4068 of 4087

88
TAILLIGHT
WHEN THE LIGHT CONTROL SW IS TURNED TO TAIL OR HEAD POSITION. THE CURRENT FLOWS TO TERMINAL 3 OF THE LIGHT
FAILURE SENSOR THROUGH THE TAIL FUSE.
WHEN THE IGNITION SW IS TURNED ON, THE CURRENT FLOWS FROM THE GAUGE FUSE TO TERMINAL 8 OF THE LIGHT FAILURE
SENSOR, AND ALSO FLOWS THROUGH THE REAR LIGHT WARNING LIGHT TO TERMINAL 4 OF THE LIGHT FAILURE SENSOR.
TAILLIGHT DISCONNECTION WARNING
WITH THE IGNITION SW ON AND THE LIGHT CONTROL SW TURNED TO TAIL OR HEAD POSITION. IF THE TAILLIGHT CIRCUIT IS
OPEN, THE LIGHT FAILURE SENSOR DETECTS THE FAILURE BY THE CHANGE IN CURRENT FLOWING FROM TERMINAL 3 OF THE
LIGHT FAILURE SENSOR TO TERMINAL 9, 11 AND THE WARNING CIRCUIT OF THE LIGHT FAILURE SENSOR IS ACTIVATED.
AS A RESULT, THE CURRENT FLOWS FROM TERMINAL 4 OF THE LIGHT FAILURE SENSOR " TERMINAL 11 " GROUND AND TURNS
THE REAR LIGHT WARNING LIGHT ON, WHICH REMAINS ON UNTIL THE LIGHT CONTROL SW IS TURNED O\
FF.
TAILLIGHT RELAY
5±3 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
L 3 LIGHT FAILURE SENSOR
4, 8±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
3±GROUND : APPROX. 12 VOLTS WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
11±GROUND : ALWAYS CONTINUITY
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C13B28F 526L 230
C14A28F 626L 330
C1528F 926R1031
F 326I16A29 (USA)R1131
F 426I16B29 (CANADA)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1A20ENGINE ROOM MAIN WIRE1B20ENGINE ROOM MAIN WIRE
1C20FLOOR WIRE
1E20INSTRUMENT PANEL WIRE
1J20COWL WIRE1K20COWL WIRE
3A22INSTRUMENT PANEL WIRE3D22INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
BU140FLOOR WIRE AND INSTRUMENT PANEL WIRE (LEFT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EA34FRONT SIDE OF RIGHT FENDER
IF36LEFT KICK PANEL
BM40BACK PANEL CENTER
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
E 1E1134ENGINE ROOM MAIN WIRE
E 434ENGINE ROOM MAIN WIREB1440FLOOR MAIN WIREE 534ENGINE ROOM MAIN WIREB1540FLOOR MAIN WIRE
SYSTEM OUTLINE
SERVICE HINTS
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Page 4070 of 4087

11 2
THEFT DETERRENT AND DOOR LOCK CONTROL
2
1I
14
1K
13
1K
11 2
3A
1
1J
1
1B
22
1H
13 3F
7
1E
18 1I
16 4
4
1D
8 1H
10 1B
5
1D 10 I8
I11
I11
B4
9
10
1 2IE1
6
IG1
17 IF2 15 IF214
IF2
16 IF2 18 IF2 5IF24
IF2
7
B
13
TAIL B
5
HE AD A
2
IG B
7
ACC A
20
+B1
A
16 E
A
6 KSW
A
19 TSW
A
14 L1
A
10 UL3
A
13 DSWD
A
11 LSWD
A
17 L2
A
18 UL2
1
13
6 4
7 24
2
31
8
21
IF 2 1
M
64 5 31 2
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
60A MAIN
120A ALT
100A AM1
LOCK
UNLOCK
LOCK
UNLOCK
15A
ECU±IG 15A
CIG10A
DOME
HEA DLIGHT
RELAY
G±Y
G±Y
G±L
R±B
L±W
L±R
W±B
W±B
W±B
W±L W
W
B±RL±R R
R
R±Y
G±W
W±B
Y
L
G±Y G G±Y
R±B
W±L
R±BG± L
R±B
G±L
L±W
L±W
R±W
L±W
L±W
R±BG±L
W±B L±R
W±B W±B W±B
G
G±Y L
W±B
W±B W±B
R±YTAI L LI GHT
RELAY
W±LW
TO FUSE º 15A TAILº
THEFT DETERRENT AND DOOR LOCK ECU
UNLOCK WA RNING SW
[IGNITION SW]
LUGGAGE COMPARTMENT
DOOR OPENER SW
DOOR KEY LOCK AND
UNLOCK SW LH
DOOR LOCK MOTOR,
DOOR UNLOCK DETE CTION AND
DOOR OPEN DETECTION SW LH
POWERWINDOWMASTERAND
DOOR LOCK CONTROL SW LH
FUSE BLOCK
L±R
BATTERY
F9
I15
L1
D7
D10
P5
T8 , T9 B A
DIODE
32 51 2
W±B
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Page 4071 of 4087

11 3
M
64 5 31 2
1K
4
2
2
2 2
I11
B7 B7 I11
EB1
3 IE1
15
IP1
20
IP1
8IP1 19
IP 1
15 IP1 6IP1 18 IP1 5IP114 IE 1
14 BT1 9
IP1
7
A
15 UL1
A
12 DSWP
A
7 LSW P
A
3 ACT±
A
4 ACT+
B
12 DS WH
A
5 TOA
1
SRLY25 13
2
31
2
31
IJ EA
2 1
PRND 2 L
146578 9
GR
R±B
L
G±W G
W
A/T INDICATOR SW
[NEUTRAL START SW AND BACK±UP LIGHT SW]
N1
2
3
FROM POWER SOYURCE SYSTEM
(
SEE PAGE 56 )
7. 5A
ST
P
N STARTER
RE LA Y
THEFT DETERRENT AND DOOR LOCK ECU
LOCK
UNLOCK
LOCK
UNLOCK
DOOR KEY LOCK AND
UNLOCK SW RH
DOOR LOCK MOTOR,
DOOR UNLOCK DETE CTION AND
DOOR OPEN DETECTION SW RH DOOR LOCK
CONTROL SW RHENGINE HOOD
COURTESY SW
LUGGAGE COMPARTMENT
DOOR OPENER MOTOR
G± Y G±L
R±B
L±W
L±R W±B
L±R L±R B
Y
W
B
L±O B
B
L±O
B
G±L L±R
G±L B
W±B W±B
L±R
W±B W±B W±B
W±B W±B
L±R R±BG±L
L±W
P±B
R±W G±W
G±Y G±Y
G±W
R±W P±B
L±W
R±BG±L L±W
P±B
R±W
G±W
L4 E5
D9
D11 D8
T8
,T
9
B A
M
1
IJ1
6
B±W
( A/T )
IJ28
B±W B
( M/T )(
M/T)
B±W
( A/T )
B±W
( M/T )
CLUTCH STA RT
SW (
M/T )
C23
( A/T )
B3 3
W±BW±B
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Page 4072 of 4087

11 4
THEFT DETERRENT AND DOOR LOCK CONTROL
2
5
1K
71E 5
44 1I
71J 1
3 11 IE1
9
2
1
BM IF BL
BT1
8BT1 7IG1 2IJ1
4
IJ1
9
B
11
HORN B
4
SH B
8
PRLY A
8
+B 2
B
1 LUG
B
10 DS WL
A
9 IND
4
I72
12
1
4
3
3
15
10 1 2
BY1
8
IH FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
25A
HAZ±HORN 30A
POWER30A
DOOR
POWER
MAIN
RELAY
W
WW W
G±R
WW
B±O
B±O
Y±RW±B
L±W
L±W
L±R
L±R
W±B W±B G±B
R±W L±G
L±G
R±W G±B
R
BR W±B
TRIP S W AND
THEFT DETERRENT
INDICATOR LIGHT
COMB INATION
METER
FUEL L I D
OPENER SOLENOID
FUEL LI D
OPENER SW
THEFT
DETERRENT
HORN
HORN
RELAY
LUGGAGE COMPARTMENT
LIGHT SW LUGGAGE COMPARTMENT
KEYUNLOCKSW
THEFT DETERRENT AND DOOR LOCK ECU T8
,T9 T1
F1 0
F1 4
T1 5
C14
L6 L5
B
A
B
6
52
31
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Page 4073 of 4087

11 5
CURRENT ALWAYS FLOWS TO TERMINAL (A)8 OF THE DOOR LOCK ECU THROUGH THE DOOR FUSE, AND TO TERMINAL (A)20
THROUGH THE DOME FUSE.
WHEN THE IGNITION SW IS TURNED ON, THE CURRENT FLOWING THROUGH THE ECU±IG FUSE " TERMINAL (A)2 OF THE ECU "
TERMINAL (B)8 FLOWS THROUGH THE COIL SIDE OF THE POWER MAIN RELAY TO GROUND, CAUSING THE RELAY TO OPERATE.
THE CURRENT FLOWING THROUGH THE POWER FUSE FLOWS TO THE DOOR LOCK CONTROL SW LH, CAUSING THE INDICATOR
LIGHT TO LIGHT UP.
1. MANUAL LOCK OPERATION
WHEN THE DOOR CONTROL SW OR KEY SW ARE PUSHED TO LOCK POSITION, A LOCK SIGNAL IS INPUT TO TERMINAL (A)17, (A)14
(FOR KEY SW) OF THE DOOR LOCK ECU AND CAUSES THE ECU TO FUNCTION. CURRENT FLOWS FROM TERMINAL (A)8 OF THE
ECU " TERMINAL (A)4 " TERMINAL 5 OF THE DOOR LOCK MOTORS " TERMINAL 2 " TERMINAL (A)3 OF THE ECU " TERMINAL
(A)16 " TO GROUND AND THE DOOR LOCK MOTOR CAUSES THE DOOR TO LOCK.
2. MANUAL UNLOCK OPERATION
WHEN THE DOOR LOCK CONTROL SW OR KEY ARE PUSHED TO UNLOCK POSITION, AN UNLOCK SIGNAL IS INPUT TO TERMINAL
(A)18, (A)10 (FOR KEY SW LH) OR (A)15 (FOR KEY SW RH) OF THE DOOR LOCK ECU AND CAUSES THE ECU TO FUNCTION.
CURRENT FLOWS FROM TERMINAL (A)8 OF THE ECU " TERMINAL (A)3 " TERMINAL 2 OF THE DOOR LOCK MOTORS " TERMINAL
5 " TERMINAL (A)4 OF THE ECU "TERMINAL (A)16 " TO GROUND AND THE DOOR LOCK MOTOR CAUSES THE DOOR TO
UNLOCK.
WHEN UNLOCK OPERATION OCCURS USING THE LH DOOR KEY SW, PERFORMING THE UNLOCK OPERATION ONCE UNLOCKS
ONLY THE DRIVER'S DOOR. TO UNLOCK ALL THE OTHER DOORS TOGETHER, UNLOCK OPERATION MUST BE PERFORMED AGAIN
WITHIN 3 SECONDS OF THE FIRST OPERATION.
3. IGNITION KEY REMINDER OPERATION
* OPERATION OF DOOR LOCK BUTTON (OPERATION OF DOOR LOCK MOTORS)
WHEN THE IGNITION KEY IS IN THE CYLINDER (UNLOCK WARNING SW ON) AND THE DOOR IS OPENED AND LOCKED USING
DOOR LOCK BUTTON (DOOR LOCK MOTOR), THE DOOR IS LOCKED ONCE BUT EACH DOOR IS UNLOCKED SOON BY THE
OPERATION OF THE ECU. AS A RESULT OF ECU ACTIVATION, THE CURRENT FLOWS FROM TERMINAL (A)8 OF THE ECU "
TERMINAL (A)3 " TERMINAL 2 OF THE DOOR LOCK MOTORS " TERMINAL 5 " TERMINAL (A)4 OF THE ECU " TERMINAL (A)16
" TO GROUND AND CAUSES ALL THE DOORS TO UNLOCK.
THE SAME APPLIES TO OPERATION OF THE DOOR LOCK CONTROL SW AND DOOR LOCK KEY SW.
* KEY LESS LOCK OPERATION
WHEN THE IGNITION KEY IS STILL INSERTED IN THE CYLINDER (UNLOCK WARNING SW ON), THE DOOR IS OPEN AND UNLOCK
OPERATION IS PREVENTED BY KEEPING THE DOOR LOCK BUTTON PRESSED TO THE LOCK SIDE, THE DOOR IS KEPT IN THE
LOCK CONDITION. IF THE DOOR IS THEN CLOSED, A SIGNAL IS INPUT TO THE ECU FROM THE DOOR COURTESY SW. THIS
ACTIVATES THE ECU AND EACH DOOR IS UNLOCKED.
SYSTEM OUTLINE
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Page 4074 of 4087

11 6
THEFT DETERRENT AND DOOR LOCK CONTROL
D 7, D 8 DOOR KEY LOCK AND UNLOCK SW LH, RH
1±2 : CLOSED WITH DOOR LOCK CYLINDER UNLOCKED WITH KEY
3±2 : CLOSED WITH DOOR LOCK CYLINDER LOCKED WITH KEY
D10, D11 DOOR LOCK MOTOR, DOOR UNLOCK DETECTION SW AND DOOR OPEN DETECTION SW LH, RH
1±4: CLOSED WITH UNLOCK POSITION
E 5 ENGINE HOOD COURTESY SW
1±2: CLOSED WITH ENGINE HOOD OPEN
I15 UNLOCK WARNING SW [IGNITION SW]
9±10: CLOSED WITH IGNITION KEY IN CYLINDER
L 5 LUGGAGE COMPARTMENT KEY UNLOCK SW
1±3: CLOSED WITH DOOR LOCK CYLINDER UNLOCK WITH KEY
L 6 LUGGAGE COMPARTMENT LIGHT SW
1±GROUND: CLOSED WITH DOOR OPEN
T 8(B) THEFT DETERRENT AND DOOR LOCK ECU
1±GROUND: CONTINUITY WITH LUGGAGE COMPARTMENT DOOR TO UNLOCK POSITION
12±GROUND: CONTINUITY WITH ENGINE HOOD OPEN
10±GROUND: CONTINUITY WITH LUGGAGE COMPARTMENT DOOR OPEN
7±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ACC OR ON POSITION
T 9(A) THEFT DETERRENT AND DOOR LOCK ECU
1±GROUND: APPROX. 12 VOLTS WITH SHIFT LEVER IN N OR P POSITION AND IGNITION SW AT ST POSITION
2±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
6±GROUND: CONTINUITY WITH IGNITION KEY IN CYLINDER
7±GROUND: CONTINUITY WITH FRONT RH DOOR TO UNLOCK POSITION
8±GROUND: ALWAYS APPROX. 12 VOLTS
10±GROUND: CONTINUITY WITH DOOR LOCK KEY SW LH TO UNLOCK POSITION
11±GROUND: CONTINUITY WITH FRONT LH DOOR TO UNLOCK POSITION
12±GROUND: CONTINUITY WITH FRONT RH DOOR OPENED
13±GROUND: CONTINUITY WITH FRONT LH DOOR OPENED
14±GROUND: CONTINUITY WITH DOOR LOCK KEY SW RH TO LOCK POSITION
15±GROUND: CONTINUITY WITH DOOR LOCK KEY SW RH TO UNLOCK POSITION
20±GROUND: ALWAYS APPROX. 12 VOLTS
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C1428F 926N 127
C2328F1028P 531
D 730F1430T 127
D 830I1529T 8B29
D 930L 129T 9A29
D1030L 430T1529
D1130L 530
E 526L 630
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
422LEFT KICK PANEL (J/B NO.1 LEFT)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
1D20FRONT DOOR LH WIRE
1E20INSTRUMENT PANEL WIRE
1H
1I20COWL WIRE1J20COWL WIRE
1K
3A22INSTRUMENT PANEL WIRE3F22INSTRUMENT PANEL WIRE
SERVICE HINTS
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Page 4078 of 4087

12
TROUBLESHOOTING
HOW TO REPLACE TERMINAL
(with terminal retainer or secondary locking
device)
1. PREPARE THE SPECIAL TOOLHINT: To remove the terminal from the connector, please construct and use the special tool or like object shown
on the left.
2. DISCONNECT CONNECTOR
3. DISENGAGE THE SECONDARY LOCKING DEVICE OR TERMINAL RETAINER
(a) Locking device must be disengaged before theterminal locking clip can be released and the terminal
removed from the connector.
(b) Use a special tool or the terminal pick to unlock the secondary locking device or terminal retainer.
NOTICE:
Do not remove the terminal retainer from connector
body.
For Non±Waterproof Type Connector
HINT: The needle insertion position varies according to the connector's shape (number of terminals
etc.), so check the position before inserting it.
ªCase 1º Raise the terminal retainer up to the temporary
lock position.
ªCase 2º Open the secondary locking device.
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Page 4079 of 4087

13
For Waterproof Type Connector
HINT: Terminal retainer color is differentaccording to connector body.
Example:
Terminal Retainer
: Connector Body
Black or White : Gray
Black or White : Dark Gray
Gray or White : Black
ªCase 1º Type where terminal retainer is pulled up
to the temporary lock position (Pull Type).
Insert the special tool into the terminal
retainer access hole ( Mark) and pull the
terminal retainer up to the temporary lock
position.
HINT: The needle insertion position varies according to the connector's shape
(Number of terminals, etc.), so check the
position before inserting it.
ªCase 2º Type which cannot be pulled as far as
Power Lock
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Page 4080 of 4087

14
TROUBLESHOOTING
Insert the tool straight into the access hole of terminal
retainer as shown.
Push the terminal retainer down to the temporary lock
position.
(c) Release the locking lug from terminal and pull theterminal out from rear.
4. INSTALL TERMINAL TO CONNECTOR (a) Insert the terminal.
HINT:
1. Make sure the terminal is positioned correctly.
2. Insert the terminal until the locking lug locks firmly.
3. Insert the terminal with terminal retainer in thetemporary lock position.
(b) Push the secondary locking device or terminal retainer into the full lock position.
5. CONNECT CONNECTOR
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Page 4081 of 4087

15
ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine and ECT ECU in this vehicle, connectors are used
which require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connectorAfter completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connectorcorrectly with the female connector, then press them
together.
(b) Tighten the bolt. Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
A/C = Air Conditioning O/D = Overdrive
ABS = Anti±Lock Brake System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
CB = Circuit Breaker SRS = Supplement Restraint System
COMB. = Combination SW = Switch
ECT = Electronic Controlled Transmission TDCL = Total Diagnostic Communication Link
ECU = Electronic Control Unit TEMP. = Temperature
EGR = Exhaust Gas Recirculation TRAC = Traction Control
FL = Fusible Link VSV = Vacuum Switching Valve
ISC = Idle Speed Control W/ = With
J/B = Junction Block W/O = Without
LH = Left-Hand
* The titles given inside the components are the names of the terminals (ter\
minal codes) and are not treatedas being abbreviations.
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