LEXUS SC400 1991 Service Repair Manual

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HOW TO USE THIS MANUAL
WITH THE IGNITION SW TURNED ON, THE CURRENT FLOWS TO TERMINAL 3 OF THE POWER\
WINDOW MASTER SW, TERMINAL 2 OF THE POWER WINDOW CONTROL RELAY
AND TERMINAL 8 OF THE POWER WINDOW SW THROUGH THE DOOR FUSE.
1.DRIVER'S WINDOW ªMANUAL UPº OPERATION BY MASTER SW
HOLDING MANUAL SW (DRIVER'S) ON ªUPº POSITION LOCATED IN POWER WINDOW MASTER SW, THE CURRENT FLOWS TO TERMINAL 5 OF THE POWER W INDOW
CONTROL RELAY THROUGH TERMINAL 3 OF THE MASTER SW TERMINAL 2 TO OPERATE A POWER WINDOW CONTROL RELAY. THUS THE CURRENT INSIDE THE RELAY
FLOWS FROM TERMINAL 2 OF THE RELAY TERMINAL 1 TERMINAL 2 OF THE POWER WINDOW MOTOR  TERMINAL 1  TERMINAL 4 OF THE RELAY  TERMINAL
3  TO GROUND. THE MOTOR TURNS TO ASCENT THE WINDOW. RELEASING THIS SW, THE ROTATION OF MOTOR IS STOPPED AND THE WINDOWS CAN STOP AT WILL
POINT.
(FOR THE ªMANUAL DOWNº OPERATION, CURRENT FLOWS IN THE REVERSE DIRECTION BECAUSE THE TERMINALS WHERE\
IT FLOWS ARE CHANGED).
2.DRIVER'S WINDOW ªAUTO DOWNº OPERATION BY MASTER SW
ONCE THE ªAUTO DOWNº BUTTON OF THE MASTER SW IS PUSHED, THE CURRENT FLO\
WS TERMINAL 9 OF THE POWER WINDOW CONTROL RELAY THROUGH TERMINAL
3 OF THE MASTER SW TERMINALS 8 AND 9 TO OPERATE THE RELAY. THUS THE CURRENT INSIDE THE POWER WINDOW CONTROL RELAY FLOWS FROM TERMINAL
2 OF THE RELAY TERMINAL 4 TERMINAL 1 OF THE POWER WINDOW MOTOR  TERMINAL 2 TERMINAL 1 OF THE RELAY  TERMINAL 3  TO GROUND.
THE MOTOR CONTINUES THE ROTATION ENABLING TO DESCENT THE WINDOW.
THE WINDOW DESCENDS TO THE END POSITION. THE CURRENT WILL BE CUT OFF TO\
RELEASE THE AUTO DOWN FUNCTION BASED ON THE INCREASING CURRENT
BETWEEN TERMINAL 2 OF THE RELAY AND TERMINAL 1 IN RELAY.
3.DRIVER'S WINDOW AUTO DOWN RELEASE OPERATION BY MASTER SW
HOLDING THE MANUAL SW (DRIVER'S) ON ªUPº POSITION IN OPERATING AUTO DOWN. THE CURRENT FROM TERMINAL 3 OF THE MASTER SW PASSING TERMINAL 2
FLOWS TERMINAL 5 OF THE RELAY AND RELEASES THE AUTO DOWN FUNCTION IN THE POWER WINDOW CONTROL RELAY. RELEASING THE HAND FROM SW, WINDOW
STOPS AND CONTINUING ON TOUCHING SW, THE FUNCTION SWITCHES TO MANUAL UP OPERATION.
4.PASSENGER'S WINDOW UP OPERATION (MASTER SW) AND WINDOW LOCK SW OPERATION
HOLDING PASSENGER'S WINDOW SW (MASTER SW) ON ªUPº, THE CURRENT FLOWS FROM TERMINAL 3 OF THE MASTER SW PASSING TERMINAL 6 TO TERMINAL 3 OF
THE POWER WINDOW SW (PASSENGER'S) TERMINAL 4 TERMINAL 2 OF THE MOTOR TERMINAL 1 TERMINAL 9 OF THE POWER WINDOW SW TERMINAL
7  TERMINAL 1 OF THE MASTER SW TERMINAL 4 TO GROUND. THE MOTOR RUNS TO ASCENT THE WINDOW. RELEASING THIS SW, THE ROTATION OF MOTOR IS
STOPPED AND WINDOW CAN STOP AT WILL PLACE.
SWITCHING THE WINDOW LOCK SW IN ªLOCKº POSITION, THE CIRCUIT IS OP\
ENED AND STOPPED THE MOTOR ROTATION.
(FOR THE DOWN OPERATION, CURRENT FLOWS IN THE REVERSE DIRECTION BECAUSE THE TERMINALS WHERE\
IT FLOWS ARE CHANGED).
P 2 POWER WINDOW CONTROL RELAY
3±GROUND: ALWAYS CONTINUITY
2±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
5±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND MASTER SW AT UP POSITION
8±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND MASTER SW AT AUTO DOWN POSITION
9±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND MASTER SW AT DOWN OR AUTO DOWN POSITION
P 4 POWER WINDOW MASTER SW
4±GROUND: ALWAYS CONTINUITY
3±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
WINDOW LOCK SW
OPEN WITH WINDOW LOCK SW AT LOCK POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
P 221P 421P 621
P 321P 52121
: RELAY BLOCKS
CODESEE PAGERELAY BLOCK (RELAY BLOCK LOCATION)
116R/B NO. 1 (INSTRUMENT PANEL LEFT SIDE)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
3B14J/B NO. 3 AND COWL WIRE (INSTRUMENT PANEL LEFT SIDE)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
ID126FRONT DOOR RH WIRE AND COWL WIRE (RIGHT KICK PANEL)
IH126FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINT LOCATION
IC24COWL LEFT
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I 524COWL WIRE
SYSTEM OUTLINE
SERVICE HINTS
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:Explains the system outline.
: Indicates values or explains the function for reference during troublesh\
ooting.
: Indicates the reference page showing the position on the vehicle of the \
parts in the system circuit.
Example: Part ªP4º (Power Window Master SW) is on page 21 of the manual.
* The letter in the code is from the first letter of the part, and the number\
indicates its orderin parts starting with that letter.
Part is 4th in order
Power Window Master SW
Example: P
4
:
Indicates the reference page showing the position on the vehicle of Relay Block Connec\
tors in the
system circuit.
Example: Connector ª1º is described on page 16 of this manual and is installed on th\
e left side of the
instrument panel.
: Indicates the reference page showing the position on the vehicle of J/B and Wire H\
arness in the system
circuit.
Example: Connector ª3Bº connects the Cowl Wire and J/B No. 3. It is described on pag\
e 14 of this manual, and is installed on the instrument panel left side.
: Indicates the reference page describing the wiring harness and wiring harness connector (the female
wiring harness is shown first, followed by the male wiring harness).
Example: Connector ªID1ºconnects the front door RH wire (female) and cowl wire (ma\
le). It is described
on page 26 of this manual, and is installed on the right side kick panel.
: Indicates the reference page showing the position of the ground points o\
n the vehicle.
Example: Ground point ªICº is described on page 24 of this manual and is installed\
on the cowl left side.
: Indicates the reference page showing the position of the splice points on the veh\
icle.
Example: Splice point ªI 5º is on the Cowl Wire Harness and is described on\
page 24 of this manual.
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* The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.
POWER SOURCE (Current Flow Chart)
The chart below shows the route by which current flows from the battery to \
each electrical source (Fusible Link, Circuit
Breaker, Fuse, etc.) and other parts.
The next page and following pages show the parts to which each electrica\
l source outputs current.
POWER SOURCE
8
HOW TO USE THIS MANUAL
The ªCurrent Flow Chartº section, describes which parts each power so\
urce (fuses, fusible links, and circuit breakers)
transmits current to. In the Power Source circuit diagram, the conditions when ba\
ttery power is supplied to each system are
explained. Since all System Circuit diagrams start from the power source, the power\
source system must be fully understood.
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* The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.
GROUND POINT
9
The ground points circuit diagram shows the connections from all major p\
arts to the respective ground points. When
troubleshooting a faulty ground point, checking the system circuits which use a common ground may help you iden\
tify the
problem ground quickly. The relationship between ground points ( , , and shown below) can also be
checked this way.
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90
ILLUMINATION
1B
2
1K
5 3G
83A 12
3A
2
3A
93G 13A10
1I
3
1K
11
1J
1 3A
1
OFF
TAIL
HEAD 2 1 1 2
1G1
5
IF 1E
18 RL RV RE TC
RL RE
826 RV
7 314
4
3
4
6
G±O
G±O
G±O
G±O
L±B
Y±V
BR L G±O
W±B
W±G
W±B
L
W±B
WW±L
G±L
LG ±B G±W G±W W±L
LG±BG±W
W±B G±O
(US A )
( CANADA )
(USA )
TAILLIGHT
RELAY
INTE GRATION
RE LAY
BATTERY FUSE
BLOCK COMBINATION
SW
120A ALT 100A AM1
INTEGRATION
RE LAY
7. 5A
PANEL
GLOVE BOX
LIGHT SW GLOVE BOX LIGHT
RHEOSTATCOMBINATION METER
(
CANADA )
LIGHT
CONTROL SW
C15
F9
G2 G1I16I16
C12
R9
W
23 15 3C
1
A
17
B
3B 4B5B 2
A
,C14 B
G±O
(
USA )
( CANADA )
B
11
A
4
B
5
B
10
B3 12
(CANADA )
A
A
TC E I LL ± T
W±B
W±G
L
I18
L
L
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91
IQ1
4 I29 I29
3 2 2 15
11
32
111
10 1
2
3G
2 3H
53F 13H13H 63H2
3H
10 3C
33F 33E63H 93E5
IQ1
2
B
10 A
2
A
9
C
5
G
G
G
G
G
G±O
G±O
G±O
G±O
G±O
W±G
W±G
W±G
W±G
W±G
W±G
W±G
W±G
W±G
W±G G
G
W±G W±G
HA ZARD S W
RADIO AND PLAYER
A/C CONTROL
AND RADIO SW
TRACTION CUT SW
AND SEAT HEATER SW
CIGARETTE LIGHTER
A/T INDICATOR LIGHT
( FOR SHIFT LEVER )
TRI P S W AND THEFT DE TE RRE NT
INDICATOR LIGHT ECT PATTERN
SELECT SW (
W/ CD PLAYER )
( W/O CD PLAYER )
H7
R4 , R5 ,R 6
A1 5
T12
C11
A21
T1 5 E8AB C
REOS TAIL
IQ1
18
L
W±G
W±G
L
L
A1 3
A/C CONTROL
ASSEMBLY25 6
G
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92
ILLUMINATION
TAILLIGHT RELAY5±3 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
C15 LIGHT CONTROL SW [COMB. SW]
3±4 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A1328E 828R 4A29
A1528F 926R 5B29
A2128G 128R 6C29
C1128G 228R 929
C12A28H 729T1229
C14B28I16A29T1529
C1528I16B29
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
1E20INSTRUMENT PANEL WIRE
1I
1J20COWL WIRE
1K
20COWL WIRE
3A
3C
3E22INSTRUMENT PANEL WIRE3F22INSTRUMENT PANEL WIRE
3G
3H
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IG136INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO.5)
IQ138INSTRUMENT PANEL WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PANEL CENTER)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I1838INSTRUMENT PANEL WIREI2938CONSOLE BOX WIRE
SERVICE HINTS
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94
INTERIOR LIGHT
21I
61E 91D10 1J 11F61F 21K1
4
1B
51H 10 1D61E11 1F 81H9
4
B6 IP 1
15
IP1 20
IJ IF
2 1 R
R
R
R
R
R±W
BR±W W±B
R±W
W±B
W±B
R
R R R R R
G±L
R±W
W±B
W±B
W±B
BR±W R±W
R±W
R±W
R±W
W±B
W±B
W±B
10A
GAUGE 7. 5A
RA DIO
NO. 210A
DOME
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
DIODE
DOOR OPEN
DETECTION SW RH
INTEGRATION
RELAY FADE OUT
CONTROL CIRCUIT1
R±W
D11
1
11
2
10
4
6
7 2
1D
8
B4
6 3 B4
4
1
4
1 A
1
B
1
A
2
B
3
IP 1
6
IF2
16
R±W P±B
L±W
R±W P±B
L±W
W±B
W±B
W±B
B7
(
USA )
( CA NADA )
DOOR KEY LOCK AND
UNLOCK SW LH
DOOR KEY LOCK AND
UNLOCK SW RH
DOOR OPEN
DETECTION SW LH D8 D7
D106 3
R±W
R±W
I16
,
AB
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95
B2I15
B2
B1 3A
6
3D
4
2 1 2
1 2
12
12
1
2 1
2
1
3
ON
DOOR
BX1
4
IP 1
17
Bc1
25
1
R
R
R
R
R
R±W
BR±W W±B
R±W
R±W
R±W
R
R
R
R
R
R
R
R
R
R
R
R R
R
R±W
R±W R±W R±W W±B W±B
BR±W
R±W R±W
R±W
W±B
IGNITION KEY CYLINDER
LIGHT
STEP LIGHT
PERSONAL LIGHT
VANITY LIGHT RH
VANITY LIGHT LHOPEN DOOR WARNING
LIGHT [COMB. METER]
DOOR COURTESY LIGHT
LH RH
LUGGAGE COMPARTMENT
LIGHT
1
2 A
11
B
12
I14
S11
P20
V6
V5
D5 D6
C12 , C 1 4
L6 BA
L7
LUGGAGE COMPARTMENT
LIGHT SW INTERIOR
MAP
MAP
OFF
I6
I7 B1
R
W±B
W±B
(
W/O M00N R00F )
( W/ M00N R00F )
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