ECU 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 3975 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
16 LEXUS SC300
4ACC
IG1
ST1
IG2
AM1 2
1
11 AM2
3A
4
1J
7
1B
5 1J
5
2
1J
5
3C
4
1B
4 1E
12 1K 13 2 1K 4
3E
13A 8
3D
13 1H 10
16 IE1
15 IG1
10 IK1 2IJ2 1IJ2 9IJ2 7IG2
4 3
2 IE2 6 IE2 1 IE2 5 IE2 11 IE2 10 I E2 MEA
IG
1A
C14 A 3F
43E 3
Y
Y
B±R R
W± R R
BR±Y
P
W
G±W
Y± B
P± B R±W
R±LL
W±B
R±B
LG±R P
LG
G±R B±W
Y± B
Y±B
P±B
P±B
R± B
LG±R P
LG
G± R W±R W±R
W
R
W± R R
BR±Y
P
W± L
W W
W±B
W±B
W±B R±L R±L B±W
16
1
20
9
23
22
3
15 10
13
10 4 1115 5
6
1
3 4 18 13 24 25 26 12 11
675
123 MC
MO
VR3
VR2
VR1
GN D
CCS
CMS
PKB
TC
PI
100A AM1
120A ALT
60A MAIN
30A AM2 30A INJ
B BAT T N&C ECT I DL OD SPD STP+ STP± LY±B
3H
12
B
(
US A )
( CANADA )
6
W
4
W± R
BATTERY CRUI SE CONT ROL
INDICATOR LI GHT
[COMB. METER]
T6
TDCL
(Tot al Diagnos tic
Communic ation Link )C3
CHECK
CONNECTOR
F9
FUSE BLOCK
C15
CRUISE
CONTROL SW
[ COMB. SW]CA NCEL
RE SUME/
ACCEL SET/
COAST
MA I N
C8
CRUISE CONTROL ACTUATOR
POTENTIO METER
MAGNETI C
CLUTCH
C1 9
CRUI SE CONT ROL E CU
S12
STOP LIGHT SW From Stop Light SW
<4±6><5±6> Fr om º STOPº Fus e
<4±6><5±6> Fr om Combination Meter
< 21±5>
Fr om Engine and ECT ECU
<3±4> 10A GAUGE
15A ECU±IG 10A DOME 7. 5A ST
B±WB±Y W
40A IGSW
Cruise Control
14
5
47
14
9
Power
Source
C1 2 B , C14 A
TC
A/ D TC
To Parking Brake SW
< 21±2>
13 IG1
P± B
P±B
To Engine and ECT ECU
<3±3> Fr om Engine and ECT ECU
<3±2>8
I15
IGNITION SW
Ins trument panel
br ace LHFront side of
r ight fender
2
1
CRUISE CONTROL INDICATOR
LIGHT[ COMB. METER] 20 B
C12 B VR1 VR2 VR3 MC L
MO
GND
1221
IJ16
IJZ10
B±W
B±W B
B±W B±W
B±W
B±W
B±W
2
(
M/T )
( A/T )
C2 3
CL UTCH
START SW
C24
CRUISE CONTROL
CLUTCH SW
( M/T )
( A/T )
10 11 12 13 17 18 19 20 21 12345 6789
14 15 16
17 18
1 2345 6789 10
23
22
21
20
19
15
14
13
12
11 16
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Page 3977 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
17 LEXUS SC300 (
Cont . ne xt pa ge )
4 ACC
IG1
ST1
AM1 3
2
1J
7 1B
21J 51J822
1B
51E 11
1E
51K 7 1K
13 1I 14 22
1H
10
1B
4
1
4 9IJ1 4IJ19IE1
8BY1 8 BT1 14 IE1 7 BT1 9 IP1 17 IG1 15 IF2 14 IF2 1 2
8A +B 2 2A
IG 7B
ACC 4B
SH 20 A
+B1 5B
HE AD 13 B
TAI L 1A
SRLY 11 B
HORN 8B
DS WP
10 B DS WL
12 B DSWH
1B LUG
5ATO
19 ATSW
6AKSW
14 AL1
10 AUL 3
3 1 2
1 1
2
2
1 1
BL BM EA IF 3F
7
3A
1
18
1E 10
1D
1
1J
16 A
E
15 AUL 1
18 A UL2
17 A LSWP
5IF2 4IF2 5IP1 14IP1 8IP1 19IP1 12 A
PCTY 7A
LSWP 4A
ACT+ 3A
ACT± 11 A
LSWD 13 A
DS WD
LOCK
UNLOCK
IJ
IF 20 IP12
31
1
3
2
LOCK
UNLOCK
1
2
8
LOCK
UNLOCK
1
3
2
LOCK
UNLOCK
G±W G± Y Y
R±B
W± L L±W L±R
P± B
R± W R
G±Y G±W
W±B
W±B
W± B
W± B
W± B G± Y
R± B G±L
W
R
R±Y
G±W L±O
G±R Y±R
R± W P± B
L±R
L±W
W± L R±B R
W
B±O
L±R
B±R
L±W L±W
W
W
W
R W
W± L
W
W± L
W± L
W
L±R
L±G
G±L
R±W
B
W±B
L
Y G±Y
G
R±B G±L
G±Y
G±W
G±W G± YG± L
R±B G± L
R±B G
G± Y
W±B
W± B W± B W± B
R
W±B
W±B
W± B
W± B W±B
R± L
B±Y
B±O
4 1
3 2
60A MAIN
100A AM1
120A ALT
40A
IGSW
F9
FUSE BL OCK I15
IGNITION SW
30A
DOOR
15A
ECU±
IG15A
CI G
25A
HAZ±HORN 10A
DOME
T1
THEFT DET ERRENT
HORN
THEFT DETERRENT AND DOOR LOCK ECU
F10
FUEL LID
OPENER SW
L±R
L±G
G± L
R± W
B
L
BATTERY
F14
FUEL LID OPENER
SOLENOID
L5
LUGGAGE COMPARTMENT
KEY UNLOCK SW E5
ENGI NE HOOD
COURTE SY SW
To Luggage Compartment
Light SW< 6±3> L4
LUGGAGE COMPARTMENT
DOOR OPENER MOT OR
L1
LUGGAGE COMPARTMENT
DOOR OPENER SW
To UNLOCK WARNING SW
<4±4><5±4>D7
DOORKEYLOCKAND
UNLOCK SW LH
P5
DOOR LOCK CONT ROL S W LH
[ POWER WI NDOW MASTER SW] Fr om Headlight Relay
<4±2><5±3>
From Taillight Relay
<4±3><5±3>
Fr om Sterter Relay
<1±3><2±2>
Fr om Hor n Rel ay
< 13±1>
To Power Main Relay
< 12±4>
D9
DOOR LOCK CONT RL
SW RH
D8
DOORKEYLOCKAND
UNLOCK SW RH
Power
Source Theft Deterrent and Door Lock Control
W± L
B±YR± L
6 2
7 T8 B , T9 A
Fr om Tilt and Power
Telesc opic ECU< 11±1>
Y
Under the center
pillar RH Ba ck
panel
centerFro nt si d e of
right fender
Lef t kic k panel
Left k ick panel Right k ick
panel
R± B
M6
5
5
6
2IG19A
To Trip SW and
Theft Deterr ent
I ndic ator Light
< 21±4>
G± B G± BIND
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Page 3978 of 4087

567 8
17 LEXUS SC300(
Cont ' d )
1I
16 4 4
1D
8 44
16 IF2 18 IF2 18 IP1 6 IP1 15 IP1
7IF2 7IP1 20IP1
1D
10
1J
1
IF IJ
645 546 312 213
MM 16 BX1 9 BX1 8 BX1 2 BX1 11 BX1 15 BX1 3 BX1
7 BY13A
6
3E
7
245610931 7 2 3
BL
R
R±W P±BL±R
L±W
W±L R± B Y
G± Y
G±W P± B
W±L G±L
L±W L±W L±W
L±R L±R W±B
R±W
W± B
L±W
R±W
R±W
R±W P±B
L±W L±W L±W
W±B
L±R
L±R
L±R
W±B
W± B
W± B
R±WP±B L±W
L±R
R±W G±L W± L
L±W
G±W G± Y Y
G± L
W± L
P±BR±L
W± B
W± B R± L
P±B
W±L
G±L Y
G±Y
G± W L±W
RR
L±W
P±B22 11
DI ODE
DI ODE
D1 0
DOOR LOCK MOTOR,
DOOR UNLOCK DETECTION SW
AND DOOR OPEN DETECTI ON SW
LH
D11
DOOR L OCK MOTOR,
DOOR UNL OCK DE TE CTI ON SW
AND DOOR OPEN DET ECTI ON SW
RHL SWD UL L UL SW CTY LSW2 LSWP +B
GNDW7
WI RE LE SS DOOR L OCK
MAIN SW
W8
WI RE LE S S DOOR L OCK ECU
Theft Deterrent and Door Lock Control
From Integration
Relay< 4±3> < 6±3>
Fr om Integration Relay
<4±3><5±3> Fr om Integration Relay
<4±3><5±3>
G±L
From Door Courtesy
Light LH< 6±3> R±W
From I ntegrat ion Relay
<4±3><5±3>
L±W
Wireless Door Lock Remote Control
P± B
T HEFT DET ERRENT AND DOOR L OCK ECU6
4
3
2
1
789101112 14 5
13 13
245 6789
10 11 12 13 14 15 16 17 18 19 20
T8 B T9 A
OR A NGE OR AN GE
Left k ick panel Right k ick panel Under the center
pillar RH
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Page 3979 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
18 LEXUS SC300
1J
7 2
3 1J
5
1B
4 2
4 1C
6
4
ACC
IG1
ST1
AM1 2
4
7 9A 10A
8BS1
10 19 22 25 23 18 12 11 24 6 1 394 105
416 5
612
4B 5A 12A 5B 12B 8A 8B 1B 6B 2B 7B 2A 7A
6 20 Bc1 4 Bc2 3 Bc2 19 Bc1 16 Bc1 5 Bc1 17 Bc1 6 Bc1 15 Bc1 7 Bc2 4 Bc1 8 Bc2
10 IP1 1 I P15BT1 6BT1 11 A
6A
1A
11 B
19 BT1
20 BT1
18 Bc1 4 BS1 81514317
EB
16543 8 7 2
52
3A
W± L W± L W
B±Y
B±R W
W
W± L
R
Y± B
B
Y
O R
BR
GR±W
G
R± W G
W
B
B
W±B
W± B W
BR
W
L±R W
W
L±R R±L
R±L L±O
L±Y
L±B
B±Y B±R L
LG
L
LG V
V
LG L
LG
L
B±R B± YL±B
L±Y
L±O L
R±B BR
G± W
R±W
L±W
B±W
LG
L
15A
ECU± I G
15A
TEL
40A
IGSW
G±B
R
60A MAIN 100A AM1
120A ALT
BATTERY
F9
FUSE BLOCK
From Radio and Player
(
w/ CD Player )
< 19±1>
Fr om Stereo Power
Amplifier
( w/o CD Player )
< 20±1>
To Radio and Player
< 19±1> < 20±3>
F12
FRONT DOOR
SPEAKER RH MIC+ GND
M1
MOBILE PHONE
TEL EP HONE TRA NS CE I VE R
C1 6
TELEPHONE
MICROPHONE
[COMB. SW]
TELEPHONE TRANSCEI VER AND SPEAKER RELAY
SPEAKER RELAY B
Power
Source Cellular Mobile Telephone
(
SHI ELDED )
(
SHIELDED )
(SHI ELDED )
(
SHIELDED )
(SHI ELDED )
(
SHIELDED )W
I15
IGNITION SW
T16 A , T17 B 2
3
5
7
8
9
10
12 4
11 1
6 5
4
3
2
1
6789101112
AB
TELEPHONE TRANSCEIVER AND SPEAKER RELAY
T16 T17
12 Fr ont s ide of
left fender
10
9
BR BR BR
BR±W BR±W BR±W
BR BR
BR±W
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Page 3980 of 4087

1234
19 LEXUS SC300
4ACC
IG1
ST1
AM1 3
2
3BV1
2 BV2 1 BV2 6 IQ2 7 I Q2 4 BV2 3 BV2 10 BV2 9 BV2 6 BV1 5 BV1 4 BV1
10 I F2 1 IF22IG2 1IG2 11Bc2 12Bc2
10 BV1
11 IQ2 3 IQ1
7 BV2 2 BV1 19 BV1 7 BV1 18 BV1
3IG2
1Bc2
10 Bc 1
9Bc1
8Bc1
23 Bc1
8 BV2
12 IQ2 24 Bc 1
II BM 1J
5
1J
8
2
1C
6
1E
10
2
1B
4 1J
7
AMP E
MU TE A MP RU ± RU +
7A
10 C
4C
8A
3A
4A
3D
1D
6D
2D
3C
1A
6 5A 2A 6A 1B 3B 2B 6B 1C 5C 9C 2C
74
MU TE
AMP
RU±
RU+
RL±
RL +
RR±
RR+
FL±
FL+
FR±
FR+ TLMT PWR VOL+ VOLC SGND B ACC ANT ANTA ANTB WP+ WP± ACC +B E ANTB ANTA ANT ACC B IG
6
3
8
5
2
1
7
3
4
9
10
26 5 1 47
B
W
P±L
R± B BR
R± B P±L
W B Y B
W R
V
V
V
R
W B
Y
B
W
P±L
BR
BR P± L
W± B Y± R
L±W
P±G GR
L±Y
B±R
R±W
B±W
GR
L±Y
BR
L±Y
GR L±Y
GR
P± G
L±W Y±R L±Y
G±RL±YGR
P± G
L±W Y±R
Y±R
L±WP±G GR
L±Y L±Y W
P±L
VV
G±RR±L
R± W G± Y W
W± L W
LG L
P
P
P
P
V LG
L W
BR
BR
B±Y
P±L
B±Y
E
1 11 2
2 22 1
60A MAIN
100A AM1
120A ALT
40A
IGSW I15
IGNITION SW
BATTERY 20A
RADIO No. 1
7. 5A
RA DI O No. 2
RADIO AND PLAYER
F9
FUSE BLOCK A3 2
AUTO ANTENNA MOT OR AND REL AY
W1 0
WOOF ER SPEAKER
AMPLIFIER
W9
WOOFER
SPEAKER
R12
REAR
SPEAKER LH
R13
REAR
SPEAKER RH
F1 0
FRONT DOOR
SPEAKER LH
15A
ECU±I G
To Telephone Tr ans ceiv er
and Speaker Relay
< 18±7>
To A/ C Cont rol Sw
and Radio Sw
< 22±4>
To A/ C Cont rol Sw
and Radio Sw
< 22±4>
To Telephone Transc eiver
and Speak er Relay
< 18±7>
Power
Source
Radio and Player
(
w/ o CD Player )
Auto Antenna
2IE1L±Y
( SHI ELDED )
P± L (
SHI EL DED )
R2 ,R3 ,R5 , R6
CDA B 12
5
34
678910 12
3456
12 34
5678910 12
3456
CD A B
R2 R3 R5 R6 RADIO AND PLAYER
L±Y
GR
3
4
Under the
as htr ay RHBack panel
center
8
7
BR
Y B
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Page 3982 of 4087

567 8
20 LEXUS SC300(
Cont ' d )
2
MUTE
5 RU±1
RU+
9
WF±
10WF+
6
AMP 8
GN D 3
B 4
ACC 7
E 6 BV2 5 BV2 2 IG2 1 IG2
11 BC2 12 BC2
10 IF2 1 IF2
6 IQ2 7 IQ2
1B FR+ 2B
FL +
5B
FR± 6B
FL ± 3B
RR+ 4B
RR± 8B
RL+ 9B
RL ±
6A AMP
11 ASGND
10 AGND
9ABEEP
3AMU TE
8AR¥
L
7AR¥
R
2AR¥
L
1AF¥
R
7AE
2
12 121
2
1
8 BV2
12 IQ2 II 23 Bc1 9 Bc1
8Bc1 1Bc2 10Bc1 1J
5
1C
6
4
AMP
7E
1
ANTB 2
ANTA 5
ANT3
B 8
ACC 6
IG
24 Bc 1
BM
B±Y
GR
L±Y
L±W B± R
L±G
Y± R
R± BL±B
P±L WB
BR
GY
W
BR L
R L±Y
R± B P± L P± L
BR
BR
P
V
P
V
P
V
P
V
LG
L
P
V
B Y
Y±R
L±W
P± G L±Y GR
B±RGR
L±Y
B±R L±G
Y±R
Y B
W R
P±L
P±L
W± B
BR
BR BR BR
R
L
BR W
Y
G
BR
P±L GR
L±Y
L±W L±B P±L
L±YGR GR
B± Y
To Telephon
Transceiver
and Relay< 18±1>
15A
ECU± I G
W
B
B±W
R± W
W9
WOOFER
SPEAKER
W10 WOOFER SPEAKER
AMPLIFIER STEREO POWER AMPLIFIERR12
REAR
SPEAKER LH
R13
REAR
SPEAKER RH
F10
FRONT DOOR
SPEAKER LH
A32
AUTO ANTENNA MOTOR AND RELAY
Radio and Player(
w/ CD Player )
Auto Antenna
(SHI ELDED )
( SHI ELDED ) (
SHIELDED )
(
PIONEER )
( PIONEER )
P± L
(NAKAMICHI )
( PI ONEER )
(
PIONEER )
BR±B
S13 , S14 AB
6
4
3
2
1
7 8 9 10 11 12 14 5
13
12
5 34
678910 A
B
STEREO POWER
AMPLIFIER
S1 3
S1 4
P±L L±B
Under the
as htr ay RH Back panel c ent er
(
PIONEER )
10 B 14 AL±YGR+B ACC
L±Y
GR
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Page 3983 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
21 LEXUS SC300 (
Cont . ne xt pa ge )
4 ACC
IG1
ST 1
IG2
AM1
3
2
6
11 AM2
1J
7
1B
4 16 IE1
20 IK110 IK2
1IE1
1J
31J 51J821B 2
1E
1E
18
1E 1H1E 2 1E
131B
IG1 20 3D
3A 4
3D
2
3C
6
3A
2
3F
1 2 1 6
3F 5
3C
5
3A
IK16
IK1 7
10 IJ1
IE110
IG118
EB
19 IG1
ED EA 13 IE2 14 IG3 W± R
R
Y
B± O Y± B
V±R V± Y
R± W
L±R
W
R±Y B
V±W V
R
L±R
P± L
R
L±R L±R
P± L
P± L
Y
B±O B±YP±L
W± L
R± W
B
W± B R±W
B
W
W
W±L
W± L W±L
W
W±R
Y±B
V±R
V± Y
R±WV±Y V± R Y±B
W± R
W
W± R
B± O
R±W R± W
B
B
R±W R±W
R±W V±Y
BR
W± B
R±W Y
W±B Y
R4713
21 11
4
12
8
7
9
2
1
2
340A IGSW
100A AM1
120A ALT
60A MAIN
30A INJ
30A AM2
14
9 I15
IGNITION SW
7. 5A I GN
10A GAUGE
15A CIG
10A DOME
15A ECU±B
From ABS ECU
<9±2>
From ABS ECU
< 8±5>
(
* 1 )
(
* 2)
6
BATTERY
F9
FUSE BLOCK
12
O2
OI L P RE SS URE SW
C5
COOLANT LEUEL
WARNING SW E6
ENGI NE OI L L EVEL
WARNING SW
P3
PARKI NG
BRAKE SWD2
DIODE
(f or Par king
Brake )
B1
BRAKE FLUID
LEVEL SW
B
B
R±W R±WR±W
R±W
B
B B
( Canada )
(
Canada )
( US A )
(USA )
(
US A )
(
US A )
(
Canada )
(
Canada )(
Canada )
(
* 2
) (
* 1)
(
US A )(
US A)
(
USA )
R±W
R± W
Fro m Dayt i me
Running Light
Relay< 4±4>
Fr om Cr uise Control
ECU< 16±2> T1 5
TRIP SW AND THEFT DETERRENT
I NDI CA TOR L I GHT
S3
SPEED SENSOR No. 1
From Tr act ion ECU
<8±7>
2
W
12 12 2 54 11 13 *
1: (
w/ Tr action Contr ol )
* 2: (
w/oTractionControl )
Power
Source Combination Meter
R±WL±R
R
4 3
SECURITY
M
H
SET
RESET A/ B
W1
WASHER
LEVEL SW
P± L
L±R
R W± R
From ABS ECU
<8±5>
( * 1)
R
R
10 11 12 13 17 18 19 20 21 12345 6789
14 15 16 12 34 56 78
9 10 1112 13 14 1516 1718
17 18
1 2345 6789 10
23
22
21
20
19
15
14
13
12
11 16
AB C
C12 C13 C14 COMBINATION METER
1 1
23
DE
FUEL SENDER
F1 7 F1 8
Rear side of
c ylinder head LH Fr ont side of
right fender Fr ont s ide of
left f ender
2
1
2 2
1 1
1
B
S HORT CONNE CTOR
1
2 12F
S23
G
S22
7BU1
From Tilt and
Power Telesc opic
ECU< 11±2>
GR
B
( M/T ) 3
G±B
From Theft Det err ent and
Door Lock ECU< 17±2>
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Page 3984 of 4087

567 8
21 LEXUS SC300(
Cont ' d )
AIR BAG
CHA RGE
OIL
OIL LEVEL COOLANT
LEVEL REAR
LI GHT
PWR
ABS TRAC
TRAC OFF
CRUISE WASHER
O/ D OFF
FUEL
SEAT BELTP
R N D 2 L
A
C
C A
A
B
B
B
C
C
C
C
C
C
C
B C
C
B
B
BA
B
A
A
C
CA A A A A A A A
C
C
C
C C C A C C B B B B
B A A C C
10 : 00
BK 1E
18 3D
10
3A
1
1J
1 1K
12
IH IF ED
IK1
8
IK2 IK1
9
1
E
3
E
2
E
1
D
BU110
BU1
3
BU1
4 11
11
1
14
19
8
18
11
13 6
18
17
16
20
19
15
13
3
15 5
1
20 9
18 8
11
87 1 2 3 4 5 16 17
2
3
4
5 10 9
12 23 12 4 17 16 7
6
15
10 22 21
W± R
RY
B±O
Y±B
V± R
V±Y
R±W
L±R
W
R± Y B
V±W V
R
L±R
P±L
Y±B
B±Y
B± W
W±B BR
B
W± B W± B BR±B
Y± G
B
Y±G
BR±B
W± B
W±B
W±B
BR±B W± B BR
Y±G
WATER
TEMP.HI GH BEAM TURN
LH
RH
BRAKE DOOR
TACHO
TRI P
SPEED
ILLUMINATIONCHECK±
ENGINE
FUEL
See Taillight and
St op Light Sy stem
<4±6><5±6>
SeeEngineControlSystem
<2±3>
Se e ABS Sy st e m< 8± 7> < 9± 3>
See Cruise Control System
< 16±3>Se e ABS an d Tr act io n
Control System< 8±7>
SeeECTandA/TIndicator
System< 3±5>
D
F1 7 , F18 E
FUEL SENDER Y±B
B±Y
B±W 24
See SRS Airbag System< 15±4>
See Charging Sy stem< 1±2>
See Headlight Sys tem< 4±1> < 5±1>
See Turn Signal and
Hazard Warning
Light Sy stem< 7±3>
See ECT System< 3±5>
From Neutr al St art SW< 1±3>
See Interier Light System< 6±3> From Igniter º TACº < 1±5>
To Engine and ECT ECU< 2±7>
To Cruise Control ECU< 16±3>
To PPS ECU< 15±2> See Illumination System
<4±7><5±7>
See ECT and A/T Indic ator
Syst em< 3±6>
See Unlock and Seat Belt
Warning Syst em< 4±4> < 5±4>
W3
WATER TEMP.
SENDER
Combination Meter
1
COMBINATION METER C12 , C13 , C14
A
AB IG1
8
Under the
c ent er
pillar LH Under the
as htr ay LH
Lef t
kick panelRear side of
c ylinder head RH
C
2
G 2
F
1
F 14
L±R
P
P
SH OR T C ON NE CT OR
S2 2 G , S23 F L±R
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Page 3985 of 4087

OVERALL ELECTRICAL WIRING DIAGRAM
1234
22 LEXUS SC300 (
Cont . ne xt pa ge )
4 ACC
IG1
ST 1
AM1 3
2
1J
7 21J
51K2
22 22
1B
4 2
1A
5
22 222 2 1
3
5 4
53
1
2
EB1 EB1 3IN1
2IN1
IN1
6
1IN1
12 IN1
EB I J 1 2
M
2 1 2
A 1
B
2
B
M
1A IJ1
2
5 4 216
4
6 12
4
74
3
W
B
P±L
B±Y
LW±G R W
P± L
R±L
L±W
G± Y
G±R R±L
R± W
BR±W G±W BR
R±Y V
W± G BR
G± Y
Y
B±R
BR±W G± W BR
R± Y V
W± B
L
BR
G±Y
RL±R
W± B
W± B W± B
W±B
W±B B
W± L W
W W
B
L
W
I15
IGNITION SW
40A IGSW
60A MAIN
120A ALT 100A AM1
F9
FUSE BLOCK
BATTERY
To Engine and
ECT ECU< 2±7>A/ C MAGNETI C
CL UTCH REL AY
10A HEATER 60A HEATER
To Radio and Player
< 19±3> < 20±2>
From Radio and Player
<19±3><20±1>
From Radio and Player
<19±3><20±1> To Radio and Player
< 19±3> < 20±2>
5 12
L±W
R±L
COOL
WARM
Power
Source Automatic Air Conditioner
R±L
R±LR±L
B
W±B W±B
B3
BLOWER
RESISTOR
(for Low
Speed )
A2
A/C LOCK SENSOR
AND A/C MAGNETIC
CLUTCH A17 , A18
A/C POWER TRANSISTOR
AB
A27
A I R MI X CONT ROL S ERV O MOTOR
HEATER
RELAY
B2
BLOWER
MOTOR Y
B±R A/ C POWER TRANSI ST OR
L±W
L±R
W
12
12
AB
A1 7 A1 8
A/C CONTROL ASSEMBLY
1 23 45 6
7 8 9 10 11 12 14 15
13 12 34
5 6 7 8 9 10 11 12 13 14 15 16 20 21 22 23 24 25 123456 7891011
17 18 19
EC D
A12 A13 A14
Front side of
lef t fender Ri gh t ki c k
panel
1
2
WhereEverybodyKnowsYourName
Page 3986 of 4087

567 8
22 LEXUS SC300(
Cont ' d )
12
II1
7
II1 2 IR2
5
IR2 4
IR2
IR1
IR1
IR1
IR1
IR2
IR2
IR2
IR2 1J
82
1E
22
5
1B
3A 3A
3A
3E
3H 3G 3B
3G
11
1E
IQ1
IQ1 IQ1 IQ1 IQ1 IQ1 II1
5
IR2
IR1
IR1
IR1
IN1
4
EB1
12 IR1
13
IR1
IR1 5
IQ117
IQ1 6
IQ1 21 12 31
IQ1 16
D
D
D
D
D
D
C
D D
D
E
E
D
IR1
4
D
C
C
D
D
E
IQ1
D
E C
D
C
E
E
E
D
D D D
D D
IQ1
C E
D
IR1
IR2
5IN11E
18
1J
1
EA IF
POWER
VOLUME AUTO
BCD SW
(Room Temp.
Contr ol SW )
M
EIR1
M
W
P± L
R±L
L±W
G± Y
G± R[ R±L
R± W
BR±W G±W BR
R±Y V
W±G BR
G± Y
Y
B±R R± G
B±Y
B±R Y
G±O V±R
V±W
L±W
BR±W G±W BR
R±Y V
L±Y
G± Y Y
B±R P± L
P
GR
G±R G Y±L
Y±G L±Y
LG±R
Y± R
L
W
L±B
Y± B P±B
W± B R
L±R
R± Y B
L±R L±O
B
R± Y L±R R
W± B P±B
L±B Y±L W
L
Y±G
LG±R
L±Y
Y±R Y± L BR
BR
BR
BR
BR
BR±W
BR
BR±W
BR±W BRBR±W
Y± GBRW
Y± L
P± B
W± B
R
BR±W
G±W BR
R±Y V
W±G BR
G± Y
Y
B±R P± L
P±B
P± B
BR
GR
BR
LG
R±L
R±L
B± Y B±Y
R± L B±Y
P± L
W
L±R
L±W
BR±W BR
BR±W
BR±W
GRBR
G±R
BR L±G
L±G
W±B
W±B W±B R
L±R
BR± W
BR
L±W
BR
BR± W
11
12
13
14
351 2 2
4
5
6
7
8
9
3
4
4
2
1
6
1
1
W/ V
MGCIGN
RDFGR ACC+B
E
DI N
MDEF
LP
MFACE TC
TPM
TW
TE
ST
TR
IG+
SET5
SET4
SET3
SET2
SET1
SAUTO
HR
S5
TP
SG
MC
MH
A/ CI N
LCKIN
LV
BL R
DOUT
TAM
TPI
MR EC
MF RS
4 5
23
8
17
8 7 3 2
16
15
14
13
12
4
9
18
22
20 3
2
7 11 9
10 25 5 8
8
1
2
3
3
2
1 9 9
5
18
8 6
10 6
8 10 1 9 13
5 9 6 7 1 15 10 15
1 4 3
127
11
7
Automatic Air Conditioner
3 1 6 5
13 3 3 5
5
12
6 19 IR2
10
DEF FACE
A3
A/C PRESSURE SW
V4
VSV(
for Water Valve )
A15
A/C CONTROL
SW AND
RADIO SW
To TDCL< 2 ±4 >
A1
A/C AMBIENT
TEMP. SENSOR
A3 3
AI R INLET CONTROL
SERVO MOTOR
To Engine and ECT ECU
<2±7>
From I gniter
< 1±5>
From Defogger
Relay< 15±3>
To TDCL< 2±4>
From Rheostat < 5±7> < 6±7> A28
AIR VENT MODE
CONTROL SERVO
MOTOR
W6
WATER TEMP. SENSOR
(
for A/C System )
A16
A/C EVAPORATOR
TEMP. SENSOR
A20
A/C SOLAR SENSOR
A19
A/C ROOM TEMP. SENSOR 15A
CIG
10A
DOME
A12 , A13 , A14
ECD
A/ C CONTROL ASSEMBLY
II1 II1
1
4
BR
G±Y
7
BR
RECIRC FRESH
3H
12 IK110
To Check Connec tor
< 2±3>BR BR
P±B P±B
Fr ont side
of right
fender Lef t kic k panel
1
2
R±LN4
NOI SE FILTER C
3
E
6
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