1991 LEXUS SC400 engine

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]
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567 8
8LEXUSSC300(
Cont ' d )
22 11 4 14 8 1716 23
1B
5
3A
6 3E
3
3B
3 1E
11 3H 12
18 IK2 15 IK2 12 IJ 2 7IO1 8IO1
9IK2 5IK2 4IK2
2IK2 10IK1
23 E BRP
4E
TRCO 1D
BRC 5E
THFA 4D
BRFA 10 D
FRO 3D
FL O 12 D
RRO 5D
RLO 15 D
ABSO 8D
BAT 2E
IG1 6D
TC 16 E
TR5 11 D
IND 14 D
WT 5
K
15 K
1
K
7D P
16 D N
1EPKB
13 IK2 3H
7
From A/ T Indicat or SW
[ NEUTRAL START SW AND
BACK±UP LIGHT]< 3±7> 26 E
BCM
25 EB±
24 EB
11 E A
12 EA±
13 EACM
14 EGND
13 DCS W
3ES1
15 E
BM 2D
STP 21 E
TR2 6E
NE O 8E
VT H 19 E
VSH 10 E
IDL1 22 E
IDL2
6 2
16 IK2
13 IJ1 3H
14
1E
18 3A
2
1J
1
IJ IF EE
213645
BCM B± B A A± ACM 1J
52
3A
4
3D
13 1E
12 2 13 14
5EE1
1
L
To Engine and
ECT ECU< 2±8>
10A
GA U GE 7. 5A
TRAC
From Stop Light SW
<5±6><4±6>
From Trottle Position
Sensor< 2±8>
FromSubThrottlePosition
Sensor< 2±8>
WB±Y
L
V± R
P±G P±L
LG±B LG
Y±B P
R± B
V±W P±B L
V
R
B± R B± R
R±W L
GR
B
R±W GR
L V± W
P±B
WA TC TC ABS W TRC
B±Y
V± R
P±G P±L
LG±B LG
Y±B
P
R±B
R
B±R RR
R±B
B±Y
W
L±R Y
Y
L±R
G±W
Y± RP±L
V±Y
Y±L R
R±B
BR
Y± R
W± B
BR
G
W L
R Y B
B
W± B Y± R
W±B
W±B
W± B
BR L
GR
L
L
P±B
L±Y W
LG±R LG±R W P±B
V± W L±G
W
P±B
P±B
P±B
W±B
R± W
W
B±Y
TS WB
C3
CHECK
CONNECTOR T6
TDCL
(
Total Diagnstic
Communic ation Link )
TRACTION ECU ABS WARNI NG AND
TRACTION OFF INDICATOR
AND TRA CT I ON I NDI CA TOR
LI GHTABS
TRAC OFF
S8
SUB THROTTL E
ACTUATOR
T12
TRACTION CUT SW (
SHI ELDED )
ABS and Traction Control
To Parking Brake SW
(
Canada )
< 21±2>
To Brake Fluide Level SW
( USA )
< 21±2>
To Parking Brake SW
< 21±3>
C1 3 , C14 KL
T1 3 , T1 4 DE 7IJ2
L±R
ABS AND TRACTION ECU TRACTION ECUABS WARNING AND TRACTION OFF INDICATOR AND
TRA CT I ON I NDI CA TOR L I GHT
Right k ick panel Left k ickpanelRea r
side of
cylinder
head LH
G±W
E
E1
20
To Engine and
ECT ECU< 2± 8> BRBR
BR
1234 67891011
14 15 16 17 18 24
512
25 26
20
19 21 22 23 13 12345 7 891011
1214 15 16 17 18 22
6
19 20 21
13 12345678
16
15
14
13
12
11
10
9 12345678
16
15
14
13
12
11
10
9 1234 67891011
14 15 16 17 18 24
512
25 26
20
19 21 22 23 13
A
A2 4 B A2 5 CA26 DT13 DARK GRAY E T1 4 DARK GRAY
12 34 56 78
910 111213 141516 1718
17 18
1 2345 6789 10
23
22
21
20
19
15
14
13
12
11 16
K
C13 L C14 123
456
12
34
F
T 3 BLACK G T4 BLACK
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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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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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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

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
WhereEverybodyKnowsYourName

Junction Block (the number in the circle is the
J/B No. and connector code is shown beside
it). Junction Blocks are shaded to clearly
separate them from other parts (different
junction blocks are shaded differently for fur-
ther clarification.).
Example:
Indicates related system.
Indicates the wiring harness and wiring har-
ness connector. The wiring harness with male
terminal is shown with arrows
Outside numerals are pin numbers.
is used to indicate different wiring and
connector, etc. when the vehicle model, engine
type, or specification is different.
Indicates a shielder cable.
Indicates and located on ground point.
The same code occuring on the next page
indicates that the wire harness is continuous.
System Title
Indicates the wiring color.
Wire colors are indicated by an alphabetical
code.
B = Black L = Blue R = Red
BR = Brown LG = Light Green V = Violet
G = Green O = Orange W = White
GR = Gray P = Pink Y = Yellow
The first letter indicates the basic wire color and the
second letter indicates the color of the stripe.
Indicates the connector to be connected to a
part (the numeral indicates the pin No.)
The position of the parts. is the same as shown
in the wiring diagram and wire routing.
Indicates the pin number of the connector.
The numbering system is different for female
and male connectors.
The numbering system for the overall wiring
diagram is the same as above.
Indicates a Relay Block. No Shading is used
and only the Relay Block No. is shown to distin-
guish it from the J/B.
243
WhereEverybodyKnowsYourName

244
Rear Window Defogger
and Mirror Heater
Remote Control Mirror
Seat Heater
Shift Lock
SRS AIRBAG
Starting
Taillight and
Stop Light
Theft Deterrent and
Door Lock Control
Turn Signal and Hazard
Warning Light
Wiper and Washer
Wireless Door Lock
Remote Control
Horn
Ignition
Illumination
Interior Light
Liquid Crystal Inner
Rear View Mirror
Moon Roof
Power Seat
(Driver's)
Power Source
Power Window
PPS (Progressive
Power Steering
Radio and Player
ABS and
Traction Control
Automatic
Air Conditioner
Auto Antenna
Back±Up Light
Cellular Mobile
Telephone
Charging
Cigarette Lighter
Combination Meter
Cruise Control
Headlight and Light Auto
Turn Off (for USA)
Headlight
(for Canada) ECT and
A/T Indicator
4±2 16±2 7±2
3±2 21±2 3±8
14±4
18±2 19±4 (w/o CD Player)
20±8 (w/ CD Player)9±2 8±2
4±7 (for USA)
5±7 (for Canada)11±2
12±311±5 (w/ Driving
Position Memory)11±7 12±1 1±5 13±2
6±2 15±2 14±2
13±2
17±7 7±3 17±2 15±3
1±315±2
Power Tilt and
Power Telescopic12±2
Power Seat (Passengerºs
and Electric Tension Header
5±2 2±2
Cornering Light ABS (Anti±Lock
Brake System)
22±2
Engine Control Unlock and Seat
Belt Warning
1±2
23±2 (w/o Driving
Position Memory)
1 23±119±2 (w/o CD Player
20±2 (w/ CD Player
14±310±2 (w/ Memory)
5±7 (w/o Memory)
4±3 (for USA)
5±3 (for Canada) 4±5 (for USA)
5±5 (for Canada)
OVERALL ELECTRICAL WIRING DIAGRAM
WhereEverybodyKnowsYourName