ECU LEXUS SC400 1991 Service Repair Manual

567 8
1LEXUSSC300(
Cont ' d )
2EC2 1EC2
7IJ1
1
345
12
B±O
B B
B±O
21
B±O
B±O
BL
B±O
W± L
B±O
W±Y
Y± G
W±Y
Y±G To Engine and ECT ECU º IGT1º < 2±8>
To Engine and ECT ECU º IGF1º < 2±8>
To Check Connec tor º IG±º < 2±4>
IGF IGT +B C±
TAC
I2
IGNITER
NO. 1
I4
IGNITION COIL
NO. 1DI STRI B UT OR
N3
NOISE FILTER
(
for Ignition System )
Ignition
B±O
8IK1 ToComb. MeterºTACHOº<21±7>
B± OB
WhereEverybodyKnowsYourName

OVERALL ELECTRICAL WIRING DIAGRAM
1234
1J
7 1J
31J 6 22
1B
4 1I
51K 42 22
22
2
4
ACC
IG1
ST1 IG2
AM1 2
1
6
11 AM2
32
41 3 1
4
2
21
21
21
21
16 IE1
15 IE1 1 EB22
1BT1 2BT1 3BT1
N P
2
3
21
413
6 14
7
9 17 BT1
21 21 BK EB1J
5
1E
12 7
8
4
15
12
13 1
814 25
1
7IJ2 9IK2 IK1
3A
4
3D
13
3B 1A IK1
IK1
2 1 M 3
W
W±R
W± R W
B± Y
B±R B±R B± Y B±Y
B± R
B± R
L±Y
G±W
B±W
B±O
B±O
L±RW
B±R B±Y B
Y
B±O
B±O
B±O
B±O
B±O
B±O
GR ±YB±R B± Y
B± O
G
G
B
L±O
L±O B
R±GP
G
G
W± B GP
R± G
W± B
W± B L±Y
G±W
YY W±B
B±R
B±YB±W
B± W
W± R
B±O B±O
B±O
B± O
B±O
W
W± B
B±R3 4
G±W W± L
LG
B±Y
B±W
G± R G±Y LG
L±Y
B±R
G± Y
G±R
LG
GR±Y
B± O
B±W B± O
B±R
B±RB± Y
R±G L±Y
G±W B
Y
B
B± Y
B±R W
L±R
B± Y LG
GR±Y
R±L
W
TE1 TE2 TT
ENG
OX 2 OX 1VF1
FP +B
5
G
3
B
W
T6TDCL
C3
CHECK CONNE CT OR
E1
CHECK ENGINE WARNI NG
LIGHT[ COMB. METER]
10A
GA UGE
EFI
MAIN
RELAY
30A
EFI
N1
NE UT RA L
ST ART SW
ST ARTER
RE LA Y
F1 6
FUEL PUMP ECU
BATTERY
F15
FUEL PUMP
30A AM2
60A MAIN
120A ALT
100A AM1
30A I NJ
I11
I NJECTOR No. 6 I10
I NJECTOR No. 5 I9
I NJECTOR No. 4 I7
I NJECTOR No. 2 I8
I NJECTOR No. 3 I6
I NJECTOR No. 1
From Starter< 1±3>
To Thef t Deter rent
and Door Loc k ECU
< 17±3> F9
FUSE BL OCK
7. 5A
ST
7. 5A
IGN
40A
IGSW I15
IGNITION SW
Engine Control
2 LEXUS SC300
GR±YB±R
VF2
TE1
W
W± B
B±Y
17 18
1 2345 6789 10
23
22
21
20
19
15
14
13
12
11 16 12 34 56 78
9 10 1112 13 14 1516 1718
AB
CHECK E NGI NE WA RNI NG
LIGHT[COMB. METER] W
C14 C13 6IJ1
1EB2
IJ112
B±R
B± R
E1
3 BR
25
From Stop Light SW
<5±6><4±6>
C1 3
IG±
From Igniter
ºTACº<1±5>
B,C14 A
19
P
BR
1IJ1 IK1
4
3B
4
Power
Source
(
Cont . ne xt pa ge )
Fr om A/C Contr ol
Assembly
< 22±7> < 22±5>
TC A/ C
P±B P±L4
11
11TC
Fr om A/C Contr ol
Assembly< 22±8> P± B G± Y
IG3
3
B±R
Under the center
pillar LH Fro nt s i de o f
left f ender
7
4
2 1IJ28
B B±W
B
C23
CLUTCH
START SW (
A/T )(
M/ T )
7IJ1
3IJ1B±O B±O
(A/ T )
3 EB1B (
M/T )
*1: (
w/ Traction Control )
* 2:
(
w/oTractionControl )
* 3: (
USA Spec. )
* 4:
(
Ex. USA Sp ec. )
WhereEverybodyKnowsYourName

567 8
EB1
EC ED D DCCCCD
CCCC
C IJ2 IJ2
IG2
EB1
C D C DC C CCC
DDCDDDDDCCCCC
ED
1 2
1
2 23
1 23
14
4 234 51
25
1346
2
B±O
B±W B±OB±Y
B± R
B± R
W
R± LBR
B± R B±Y W
L±R
B±Y LG
GR±Y B Y B
G±W L±Y
R± G P B± R
B± R
18 19 17 16 15 46 23 44 34
31 32 34 32 35 33 33 24 2 76 1 37B
B± Y
B±R W
L±R
W± B
W± B
BR
LG±BL±WV±R
G± YB± Y
B± O P
B±W B± O
BR
W
L±R
B±R
P
B±O
BR
BR
#30 #20 #40 #50 #60 THG ACMG THW A/C
B±R
B±R
B±R
EB1
Fro m
Spe ed Sen sor
< 21±7>
P± L
Y± L
V± Y
Y± G
W± Y Y±R
L±R
Y± B
Y± G L±R
L±R
BR
BR
65 63 42 64 43 38 39 40 58 57 41 45 66 A9
AIR FLOW METER
From Trac tion ECU
< 8±8>
From I gniter
< 1±6>
7P
E2 IDL2 VTA2
IDL1
VTA1
THA
VC KS
IGT
IGF
VT 01
VT 02
NEO
TR
IGSW
NS W
SP1
M±REL
BATT
ISC3
ISC1
ISC4
ISC2
+B1
+B I1
ISC
VALVEBR
R±BBR
Y± L
L±R
R
Y
L±R
L±R
L±R
BR
L±R
BR
BR
BR
BR
BR W
G
From Magnet ic
Cl ut ch Rel ay
< 22±1>
To A/ C Amp lif ie r
< 22±7>
E3
EGR GAS TEMP. SENSOR
E2
EFI WATER TEMP. SENSOR
S9
SUB THROTTL E
POSITI ON SENSOR T2
THROTTLE
POSITI ON SENSOR
BR
Engine Control
2LEXUSSC300
(
Cont ' d )
ENGI NE AND ECT ECU, ENGI NE ECU *
1: (
w/ Trac tion Control )
(
* 1)
( * 2)
( * 1)
( * 2)
(
* 1 ) *
2:
(
w/ o Tr a ct i o n Co nt r ol )
(
* 1 ) To Trac ti on
ECU< 8±8>
R±B
R
4311 8
B±O
BR (
* 3)
(
* 3) *
3: (
US A S pe c. )
* 4:
(
Ex . USA Spe c. )
E9 , E10 DC
BR
Front side of
intake manifold Rear side of
c ylinder head RH Rear side of
c ylinder head RH
C
C
C 1 2
1
2
2
1
C
C
C
C
C
C
D
D
C
C
C
C
D
D
C
D
C
D
D
20
77
27
7
25
26
22
21
80
79
4
69
4
6
29
20
28
19
17
V7
VSV (
for Int ake
Contr ol Valve )
V2
VSV
(
for EVAP )
V1
VSV
(
for EGR )
BY1
BY1
BY1 BY1
BR
R±B
(
* 4 )
W
(
* 4 )
B±R
BR±W
(
* 3 )
R±L
(
* 3
)
3142 1256
IK2
IK2
12
22
C
C
1
O3
OXYGEN SENSOR
MAIN No. 1
(
ON Front Side )
C48 71 61 75 74
1
O4
OXYGEN SENSOR
MAIN No. 2
(
ON Rear Side )
C
D
1 2
35 47
P2 0
POWER STEERING
PRESSURE SW
IK11
IJ1
IJ1
(SHIELDED )2341 C
C
1
1 49
50
D1 3
DI ST RI B UTOR
( SHIELDED )
EC
Front side of
intake manifold
G±Y G± R
8
14
K1
No. 1(
ON Fr ont Side )
KNOCK SENSOR
K2
No. 2 (
ON Rear Side ) BR BR
BR
W
W L
B Y
R R±G
P
W± B
W± B G±W
L±Y
GR±Y LG
B±Y
G±Y
BR
BR
BR
G1 G2 G± NE
#10
TT TE2 VF2 TE1 VF1 W STP E1 E1 1 E0 2 E01 DI FPC G1 G2 G± NE KNK1 KNK2 STA ACI S
PS OX2 OX1 HT OX3 EGR EVAP 39
G± R G±B
B±W BR± W
BR± W
BR
B±R
B±R
B±R
B±R
W
BR± W
W
R±L
BR BR
BR
R±L W
LG±B BR
BR
(
SHI ELDED )
(
SHI EL DED )
(
SHI ELDED )
( SHIELDED )
O8
OXYGEN SENSOR SUB
(
for California )
BR
BR
Y B
R± L
BR
(* 4)
(
* 4)
(A/ T )
WhereEverybodyKnowsYourName

OVERALL ELECTRICAL WIRING DIAGRAM
1234
3 LEXUS SC300 (
Cont . ne xt pa ge )
4 ACC
IG1
ST1
IG2
AM1 2
6
11 AM2
1J
7 21J
3
2
2
1B
4
2221I
5
EB1 EB2 4 EB1 11 IJ2 3 IJ2
16 IE1
9BS2
B
S1
B
OD1
8BS3
80 BEO1
79 BEO2
42 BVTA2
63 BIDL2
23 BSP2
3BSP2±
69 BE1
4BE11
24 A
M±REL 32 A
+B 1 31 A
+B 33 A
BATT 76 B
NSW
1A
IGSW 2A
SP1 41 B
VC 43 B
VT A1 65 B
E2 64 B
IDL1 44 B
THW 26 B
G1 25 B
G2 6B
G± 5B
NE 10 A
L 9A
2
4 3
4 2
123 SeeEngineControl
Sy stem< 2±8>
See Engine Contr ol
Syst em< 2±6>
W±R W± R B±Y
W± L
W
B±OW
B±O
B± O
B±R
B±R
B±R
B±O
B±Y
B±O PP B±OB±Y
BR±Y
W± RR± L
EB EE EE 1218 A
P 28 A
OD2 12 A
OD1
17 A TT
29 B VF1
20 A TE1
28 B VF 2
21 IK1 22 IK1
3 4
See Engine Contr ol Sy stem< 2±5>
W
G
G± O Y
GR ±R
W±B
W±B
W±B
BR
BR W± B
W± B
P
V BR
BR
WG
G±O
GR±R BR± Y W± B
G±O G±O Y G± O
W
B±Y
I15
IGNITION SW
W± R W W
60A MAIN
100A AM1
120A ALT
30A AM2
30A INJ
F9
FUSE BLOCK
40A IGSW
EF I
MAIN
RE LA Y
30A
EFI
7. 5A
IGN
3 1
83B±RE1
ECT SOLENOID
NO. 1 NO. 2
NO. 3
S4
SPEED SENSOR
NO. 2 (
for ECT ) E8
ECT
PATTERN
SELECT SW
From Combination
Meter< 21±4>
To Cruise Cont rol ECU
< 16±3>
See Engine Contr ol Sy stem
< 2±7>
B± Y
ENGI NE AND ECT ECU
Power
Source ECT and A/T Indicator
BATTERY
7 4 91413
6
POWER
NORMAL
A
19 TE2
E9 , E10
BA ENGI NE AND ECT ECU
ENGINE AND ECT ECU
Fr ont s ide of
left fender Rear side of
c ylinder head LH Rear s ide of
cy linder head LH
3
1
To Cruise Control
ECU< 16±3>
See Engine Control
Sy st e m< 2 ±8 > LG
Y B
W12 10 10
30
50
70
1
21
41
61 2
22
42
62 3
23
43
63 4
24
44
64 5
25
45
65 6
26
46
66 7
27
47
67 8
28
48
68 9
29
49
69 11
31
51
71 20
40
60
80
19
39
59
79
18
38
58
78
17
37
57
77
16
36
56
76
15
35
55
75
14
34
54
74
13
33
53
73
12
32
52
72
1020
30
40
1
11
21
31 2
12
22
32 3
13
23
33 4
14
24
34 5
15
25
35 6
16
26
36 7
17
27
37 8
18
28
38 9
19
29
39
A
E1 0 DARK GRAY
B
E 9 DARK GRAY
WhereEverybodyKnowsYourName

5678
3 LEXUS SC300(
Con' t )
1J
5
3B
53D 33A4
3D
53D 63B43D 13 1E
12 1H 12
IJ110
IK1 IK1 I K1 I K1 IK1 IK1
1 2 23 E
4D 1C 2C 3C 4C 5C 16C
E
1
C
18
3
3H
1
3A 1
1J
18
1E
10
3D
9
3D
IF
9
N1
A/T INDI CATOR SW
[ NEUTRAL ST ART SW AND
BACK±UP LIGHT SW]
A2 1
A/ T I NDI CAT OR LI GHT
( for shift lever )
GR±R
Y
G±O G
W
B± W
YYYWG L
GR
GR±R W± B
W± BW± B
W± B W± B
WL
W L
W
WL GR±R
GR±R
GR±R
Y
GR ±R
W± B
G
G±W R±B
GR
R±BGR
G
G±W
G
G±W L
R±B GR
G± O
Y
G
G± W R± B
GR
W L
G
G±W R±B
GR GR±R
Y
Y
B± W
12 11 13 14 16 1710
9
8
7
6
5
PRN D 2 L
4
L 2
D N R P
ECT POWER O/ D OFF
O5
O/DMAINSW ToABSECUandTractionECU
(
W/ Tr ac tion Cont rol )
<8±5>
ECT and A/T Indicator
BU1 8
BM
55 44
R± B R±B R±B
W± B
W± B
W±B R±B
Back±Up LightBACK±UP LIGHT
[ REAR COMB. LIGHT]
R1 1
RH
R10
LH
To TDCL º ECTº
<2±4>
10A
GA UGE
146 578
PRN D 2 L
C12 ,C 13 ,C 14
CD E
A/ T I NDI CATOR LI GHT
[COMB. METER] 7BU1
To Ti l t and Po we r
Telescopic ECU< 11±2>
GR
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
C12C C13D C14E
A/T INDICATOR LIGHT
[COMB. METER]
GR Left kick panel Back panel c ent er
WhereEverybodyKnowsYourName

OVERALL ELECTRICAL WIRING DIAGRAM
1234
4 LEXUS SC300
1J
7 221J
81B2
4
1B
5
1B
4 1K
11
22
22
44
1I 1E
3
4
1 2 23
1
5
4
ACC
IG1
ST1
AM1 3
2
1 21
2 1
21
2
19 IE1 12 IE1 5IE1 6IE1
9IG1
4
7
6 4
19 15
1
3 20 16
2
18 4
97 313
6 7
IJ 1J
5
3A 1E 1C
1A
1I
15
1C
1F
1K 3D
7B 1A
2 1 9
10
BK IF 1H
1K 1J 1E W± BY Y
G± O G
G
W± L
Y
Y
W± B
R± Y
W± G
G± W
W± LW± L
W± L W
W± B R± W
W± B
R
L±W P± B
G±L
R± W
R± W
BR± W
B±L
B±L
W±B
W± B
W±B W±B W±B
W±B W±B
R± W
R± W
R± WR± W
R± W R±B R±B
W
G± W
G± W W
P±L
W± L
G G
P±L
B±Y
W
R± Y R±L R
YVPower
Source
F9
FUSE BL OCK60A MAIN 100A AM1
120A ALT
W
R±Y
40A
IGSW
LO
HI
HI
LO
HEADLIGHT LH
HEADLIGHT RH
HEADLIGHT
RELAY
Fr om Connerring Light
Relay< 7±2> DI ODE10A DOME
7. 5A RADIO No. 2
LIGHT
CONTROL
DIMMER
OFF
TAIL
HEAD
LOW
HIGH
FLASH HU HF FL E D T H E L
C15
COMBINATI ON SW
BATTERY
C13
HIGH BEAM
I NDI CA TOR L I GHT
[COMB. METER]
To Door Lock Mot or and
Unlock Detection SW and
Doo r Open De t ect i on S W LH
<17±5><17±6>
To Door Lock Mot or and
Unlock Detection SW and
Doo r Open De t ect i on S W RH
< 17±6>
From Open Door War ning Light
From Per sonal Light< 6±2>
B4
BACKLE SW LH
I15
UNLOCK WARNI NG SW
[IGNITION SW] SEAT BELT WARNI NG
LI GHT[ COMB. MET ER]
5118
TAIL LIGHT
RELAY
To Thef t
Deter rent and
Do or L oc k ECU
< 17±3>
7. 5A PANEL15A TAIL
10A
GAUGE
3 12 2
13 4Y
BELT
H± LP B A CC TRLY I NTB I G
BKL KEY
12 12
9
To Theft Deterr ent and
Door Lock ECU< 17±3>
I15
IGNITION SW
I16
I NTEGRAT I ON REL AY
H
T
G± L
R±G
1 3
2
B±Y
G±O
1C
16DI ODE
1E
1
9
C1 2 , C1 4 AB
6
From Tens ion Reducer
Solenoid LH< 11±7>
Fr om Thef t Deter rent and
Door Loc k ECU< 17±2>
Fr om Day /Night Shift SW< 12±1>
Fr om Tilt and Power Teles copic
ECU< 11±1> Y
Y
B±L
W±B
5C 4C
CC 3 111 12 7
6428 510 GND
INTEGRATI ON RELAY
SEAT BELT
WARNING LIGHT
[COMB. METER]12
3456
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 C
A
B I16
C12
C1 4
Headlight and Light Auto Turn Off (
for USA ) Unlock and Seat Belt Warning
(
for USA )
(
Cont . ne xt pa ge )
2
1
1I 3
R± YR± Y
C6 C
21
Y
Right kic k panel
Under t he c ent er pillar LH Left k ick panel
IG1
8
15A
HEAD
RH
15A
HE AD
LH
W±B R
R
R
R
R
R 6Ba2
Ba1
11
5Ba2 Ba1
12 (
w/ ME MORY )
( w/ o MEMORY )
(
w/ Me mo r y )
( w/ o Memory )
WhereEverybodyKnowsYourName

567 8
4LEXUSSC300(
Cont ' d )
1
2
1
2 1D
11 E 1I
10
3G
1
1B
2
3A
9
1C
10
1E
20
1H
1
9BU1
1Bd15IG7
11 Bc 1
Be1 2 1
1
2
3A
10
1 2
3 84
921117
3G
83A 2
3A
1
2
12
1
1
4
1
2 1
2
EA BM BL 2Bd14
1
3
8
2 10
3H
3
3C
3
3F
2
3G
5
3H
1
3F 6
1
2
1
3
2
2
9
5
1
10
F 5
G
IQ1
2
6
7 IQ1
4
12
3A 9
3E 6
3E 6
3E
6
3H 2
3H 1
3H 1
2
10 11 1 2
GW±G
G
G
GW±G W± GW±G
GW±G
G±O
G±O
G±O
G±O
G±O W±G W± G W± G
W± G W± G
W± G
G± W
W± BY Y
G±O
G
G
W± L
G
G
G
GW±BW± B W± B W± B
G
Y
V± G
V± G Y
G±W
G± W
W±B
GGGG
G
W
G± W
G± W
B
W± B R± W
B
G±W G±W G±O
G±O
W± B W
W±GBR
Y± V L±B L
W±B
W± B
W± B
W±B
W±B
G
G
W± G W± G
W±B
±PK ±STP E HS +STP
ETCRLRVREILL±
7
G± O
G± O
+PK BWRN
T
15A
STOP
F3
LH
F4
RH
FRONT
CLEARANCE LI GHT
L3
LI GHT FAILURE SENSOR
RE AR LI GHT WARNI NG
LI GHT[ COMB. MET ER]
S12
STOP LIGHT SW
To ABS ECU<8±3><9±4>
To Shif t Lock ECU< 15±2>
G2
GLOVE BOX
LI GHT SW
F5
LH
F6
RH
FRONT SIDE
MARKER LIGHT
L2
LI CE NCE
PLATE LIGHT
W± B W±B
W±BH9
HIGH MOUNT
STOP LIGHT
H8
HIGH MOUNT
STOP LIGHT A1
A/C CONTROL
ASSEMBLY
A15
A / C C ON TR OL SW
AND RADIO SW
RADIO AND PLAYER
( w/o CD Player )
R4
RADIO AND PLAYER
( w/ CD Player )
T1 2
TRACTION CUT SW AND
SEAT HEATER SW
C1 1
CIGARETTE LIGHTER
A21
A/T INDICATOR LIGHT E8
ECT PATTERN
SELECT SW
T1 5
TRIP SW AND THEFT DETERRENT
INDICATOR LI GHT
R9
RHEOSTAT
G1
GLOVE BOX
55
13 13W±B
W±B
W± B W± B W± B
R± W
G±R
R± W G±R G±RTAI L AND
STOP LIGHT
[REAR COMB.
LIGHT]
R1 0
LH
R1 1
RH
TAIL
ST OP
TAIL
ST OP
To Engine and ECT ECU< 2±3>
To Traction ECU< 8±8>
To Cr uise Control ECU< 16±4>
To Cruise c ont rol
ECU< 16±4>
To Po wer Se at E CU
(Driver' s )
< 11±5>
G± W
G±W
(
* 1 )
(
* 2 )
( * 2 )
(
* 1
)
C13 , C14
ED
H
H
H
H
I3C
1
17
2345
COMBINATI ON METER C12 , C14 IH R5 , R6
FG
12 34
5678910
12
3456
RADIO AND PLAYER
(
w/ o CD Pl ay er )
Taillight and Stop Light (
for USA )
Illumination(
for USA )
*2:
(
w/o Rear Spoiler )
*
1: (
w/ Rear Spoiler )
W
G±W
G± O
Fro nt s i de of
right fender Under t he
c ent er pillar RH
Back panel c ent er 23
G
W± G
H7
HA ZA RD SW
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 C1 2 I
C1 4 H
COMBI NATI ON METER
RE AR LI GHT WARNI NG
LI GHT[ COMB. MET ER]
WhereEverybodyKnowsYourName

OVERALL ELECTRICAL WIRING DIAGRAM
1234
5 LEXUS SC300
1J
7 22 2 21J
81B2
4
1B
5
1B
4 1K
11
22 22
22
44
1I 1E
3 1
4 2 3
4
1 2 23
1
5
4
ACC
IG1
ST1
AM1 3
2
1 21 2 1
21
2
19 IE1 12 IE1 11 IE1 5IE1 6IE1
9IG1
4
7
6 4
15 19 21 1
3 16 20 22 2
18 497 313
6 7
IJ 8IG1 1J
5
3A 1E 1C
1A
1I
15
1C
1F
1K 3D
7B 1A
2 1 9
10
BK IF 1H
1K 1J 1E W± BY Y
G± O G
G
W± L
Y
Y
W±B
R
W±B W±B R±YW± G
G± W
W± LW± L
W± L W
W± B
R±W W± B
W± B
R
R
LG±B G±W
L±W P± B
G±L
R± W
R± W
BR± W
B±L
B± L
W± B
W± B
W±B W±B W±B W±B W±B
W± B W± B
R±W
R±W
R
W±B R±B R± W
R± W R±G
R
W
G± W
G± W R
R R
W
P±L W
G G
P±L
B±Y
W
R± Y R±L R
Y VPower
Source
F9
FUSE BL OCK60A MAIN
100A AM1
120A ALT
22W
R±Y
TH
15A
HEAD
LH±LWR
15A HEAD RH±LWR
15A HEAD RH±UPR 15 A HEA D L H± UP R
40A
IGSW
H3LH
H4 RH
H2 RH H1LH
HEADLIGHT
(
LO )
HEADLIGHT (
HI )
DIMMER
RE LA Y HEADLIGHT
RELAY
Fr om Connerring Light
Relay< 8±7> DI ODE10A DOME
7. 5A RADIO No. 2
LIGHT
CONTROL
DIMMER
OFF
TAI L
HE AD
LOW
HI GH
FLASH ED HL HU HF EL T H
C15
COMBINATI ON
SW
BATTERY
C13
HIGH BEAM
I NDI CA TOR L I GHT
[COMB. METER]
To Door Lock Mot or and
Unlock Detection SW and
Doo r Open De t ect i on S W LH
< 17±1>
To Door Lock Mot or and
Unlock Detection SW and
Doo r Open De t ect i on S W RH
< 17±1> From Open Door War ning Light
From Per sonal Light< 6±2>
B4
BACKLE SW LH
I15
UNLOCK WARNING SW
[IGNITION SW] SEAT BELT WARNI NG
LI GHT[ COMB. MET ER]
5118
TAIL LIGHT
RELAY
To Thef t
Deter rent and
Do or L oc k ECU
< 17±3>
7. 5A PANEL15A TAIL
10A
GAUGE
3 12 2
13 4Y
BELT
H± LP B A CC TA I L I NTB I G
BKL KEY
12 2
9
To Thef t Deter rent
and Door Loc k ECU
< 17±3>
I15
IGNITION SW
I16
I NTEGRAT I ON REL AY
DIM TOUT
HF
HU
Y± B
R±L
CHG± P KBY±G
B
From Alternator º Lº < 1±2>
From Park ing Br ake SW < 21±2>
1 3 2
B±Y
G± O
1C
16DI ODE
1E
1
9
C1 2 , C1 4 AB
6
From Tens ion Reducer
Solenoid LH< 11±7>
Fr om Thef t Deter rent and
Door Loc k ECU< 17±2>
Fr om Day /Night Shift SW< 12±1>
Fr om Tilt and Power Teles copic
ECU< 11±1> Y
Y
W±B
12C 11C 5C
CCC CC 4C2C 9 8 7 10 13 111 12 7
642 8 105 GND
I NTEGRATI ON REL AY
SEAT BELT
WARNING LIGHT
[COMB. METER]
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 C
A
B I16
C12
C1 4
Headlight (
for Canada ) Unlock and
Seat Belt Warning
(
for Canada )
(
Cont . ne xt pa ge )
2
1
3C 1C
13
Y
12345678910111213
18
17
IG
W±B
6Ba2Ba 1
11
5Ba2 Ba 1
12 (
w/ Memor y )
( w/o Memory )
B±L
( w/ Memor y )
( w/o Memory )
XX
Right kic k panel
Unlock the center
pillar LHLeft kic k
panel
WhereEverybodyKnowsYourName

567 8
5LEXUSSC300(
Cont ' d )
1
2
1
2 1D
11 E 1I
10
3G
1
1B
2
3A
9
1C
10
1E
20
1H
1
9BU1
1Bd15IG7
11 Bc 1
Bc1 2 1
1 2
3A
10
1 2
3 84
921117
3G
83A 2
3A
1
2
12
1
1
4
1
2 1
2
EA BM BL 2Bd14
1
3
8
2 3
3C
3
3F
5
3H
1
3F 1
2
1
3
2
9
5
1
10
F 5
G
6
7
12
3A 9
3E 6
3E 6
3E
6
3H 2
3H 1
3H 1
2
10 11 1 2
G
GW±G
W± G
GW±G
G±O
G±O
G±O
G±O
G±O W± G W± G W± G
W± G W± G
W± G
G± W
W± BY Y
G±O
G
G
W± L
G
G
G
GW±BW± B W± B W± B
G
Y
V± G
V± G Y
G±W
G± W
W± B
GGG
G
W
G± W
G± W
B
W± B R± W
B
G±W G± W G±O
G±O
W
±B W
W± GBR
Y±V L±B L
W± B
W± B
W± B
W± B
W± B
G
W± G
W± B
±PK ±STP E HS +STP
ETCRLRVREILL±
7
G± O
G± O
+PK BWRN
T
15A
STOP
F3
LH
F4
RH
FRONT
CLEARANCE LI GHT
L3
LI GHT FAI LURE SENSOR
RE AR LI GHT WARNI NG
LI GHT[ COMB. MET ER]
S12
STOP L I GHT SW
To ABS ECU<8±3><9±4>
To Shi f t Lock ECU< 15±2>
G2
GLOVE BOX
LI GHT SW
F5
LH
F6
RH
FRONT SI DE
MARKER L I GHT
L2
LI CE NCE
PLATE LI GHT
W± BW± B
W± BH9
HI GH MOUNT
STOP L I GHT
H8
HI GH MOUNT
STOP L I GHT A15
A / C C ON TR OL SW
AND RADI O SW
RADI O AND PLAYER
( w/ o CD Pl ayer )
R2
RADI O AND PLAYER
( w/ CD Pl ayer )
T1 2
TRACTI ON CUT SW AND
SEAT HEATER SW
C1 1
CI GARETTE LI GHTER
A21
A/ T I NDI CATOR LI GHT E8
ECT PATTERN
SELECT SW
T1 5
TRI P SW AND THEFT DETERRENT
I NDI CATOR LI GHT
R9
RHEOSTAT
G1
GLOVE BOX
55
13 13W± B
W± B
W± B W± B W± B
R± W
G± R
R± W G± R G±RTAI L AND
STOP LI GHT
[ REAR COMB.
LI GHT]
R1 0
LH
R1 1
RH
TAI L
ST OP
TAI L
ST OP
To Engi ne and ECT ECU< 2±3>
To Tr act i on ECU< 8±8>
To Cr ui se Cont r ol ECU< 16±4>
To Cr ui se c ont r ol
ECU< 16±4>
To Po wer Se at E CU
(Dr i ver ' s )
< 11±5>
G± W
G± W
(
* 2
)
( * 2
)
(
* 1
)
C13 , C14
ED
H
H
H
H
I3C
1
17
2345
COMBI NATI ON METER C12 , C14 IH R5 , R6
FG
12 34
5678910
12
3456
RADI O AND PLAYER
(
w/ o CD Pl ay er )
Taillight and Stop Light (
for Canada )
Illumination(
for Canada )
*2:
(
w/ o Rear Spoi l er )
*
1:
(
w/ Rear Spoi l er )
W 10 11 12 13 17 18 19 20 2112345 6789
14 15 16
17 18
1 2345 6789 10
23
22
21
20
19
15
14
13
12
11 16 C1 2 I
C1 4 H
COMBI NATI ON METER
G±W
W± L
G± O (
* 1
)
Fr o nt s i de of
r i ght f ender Fr o nt s i de o f
l ef t f ender Bac k panel cent er
RE AR LI GHT WARNI NG
LI GHT[ COMB. MET ER]
10
3H
2
3G 62
IQ1 2
IQ14
GW±G GW±G
G
W ±G
A1
A/ C CONTROL
ASSEMBLY
23G
W± GH7
HAZARD SW
R5 F G
R6
WhereEverybodyKnowsYourName

OVERALL ELECTRICAL WIRING DIAGRAM
1234
6 LEXUS SC300
2
3A
6
2
1F
81H 91D61H10 1E 11
3D
4
2 1 2
12
1 2
1 2
1
6 22
12
11
3
7 11 A
12 B
4BX1 17 IP1
25 Bc 1
1F
6
1J
1
IF 1
To Int egr ation Relay
< 5±3> < 4±3>
1 2
5
1B
W±B
W± B
RR
W
W±B
W±B
W± B
W± B
BR±WR±W R±W R
RR
R
R
R
R
RR
R
R
RR
R± W R±W R± W
R±W
R± W R± W
R± W R
R±W
W
R
10A
DOME
60A MAINF9
FUSE BL OCK
VANITY LI GHT
V5
LH
V6
RH
P20
PERSONAL
LIGHT
LH
RH
ON
OFF
DOOR
I14
IGNITION KEY
CY LI NDER LI GHT
S1 1
ST EP LI GHT
D5
DOOR COURTESY
LIGHT LH
L7
LUGGAGE COMPARTMENT
LIGHT
D6
DOOR COURTESY
LIGHT RH
To Door Lock Motor,
Do or Unl oc k De t ec t i on SW an d
Do or Ope n De t ec t i on S W LH
< 17±5>
From CD Automatic Chenger
< 20±1>
4o Door Lock Motor,
Do or Unl oc k De t ec t i on SW an d
Do or Ope n De t ec t i on S W RH
< 17±5>
To Int egr ation Relay
< 5±3> < 4±3>
L6
LUGGAGE COMPARTMENT
LIGHT SW
OPEN DOOR WARNING
LI GHT [ COMB. MET ER]
BATTERY
Power
Source Interior Light
W
From Theft Deterrent
and Door Lock ECU
< 17±2> R±W
C12 , C14
BA OPEN DOOR WARNI NG LIGHT
[COMB. METER]
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 B
A
C12
C14
Lef t kic k panel
W± B
(
w/oMoonRoof )
( w/ Moon Roof )
WhereEverybodyKnowsYourName