1991 LEXUS SC400 engine

221
1E
19 1E 14
1H
11 1H 7
IK1
16 IK1 17
2
L
LH
TURN
A
5A 16 B 17 B16
C
23
1 IK2
5 IK2
4
SEAT BELT
ABS
TRAC
TRAC OFF
A
19 A 7B15 B 5B1
W±B
LG±R W
V
LG±R
TO ABS AND
TRACTION ECU
(
IND )
TO ABS AND
TRACTION ECU
( WT ) G
W G±Y
G±B
G±B G±Y WG
R±W
FROM
A/T INDICATOR SW
OIL PRESSURE SW RH
Y±B
O2
COMBINATION METER C12 , C 1 3
,C14
ABC
I23
WW
TO TDCL (
TRC )
IK 2
9
Y±B
I22
L±Y
IO1
7
L±Y
I23
L
L±Y
TO ENGINE AND
ECT ECU
(
W ) L±Y
TO CHAK
CONNECTOR (
W )
L
TO ABS AND
TRACTION ECU
(
WA ) L
TO CHECK
CONNECTOR (
LP )
IK2
2
L
W
1E
1
SEAT BELT WARNING
RELAY [INTEGRATION RELAY] CHECK ENGINE
B
3
L±Y
IK1
20
FROM TURN
SIGNAL FLASHER
3D
10
3A2
3A 1
W±B
G±O
OIL
G±O
WhereEverybodyKnowsYourName

222
COMBINATION METER
O/D OFF
CRUISE CONTROL
3A
10 3A 9
3C
1
IG1
5 1I
3
A
5
G±O
G±O
G±O
C
5C 4C3C2
413
A
20 A 18
3C
43B 4
3D
63D 53D5
3F
4
3E
1
IG1
15
TO ENGINE AND
ECT ECU (
OD2 )
TO CRUISE
CONTROL
ECU
(
PI )
TO TDCL
( A/D )
TO O/D MAIN SW TO TDCL (
ECT )
RHEOSTAT
2 87
G± O
G±O
G±O
FROM POWER SOURCE SYSTEM(
SEE PAGE 56 )
7. 5A
PANEL (CANADA )
( CANADA )
(
USA )
I16
INTEGRATION
RELAY
COMBINATION METER C12 , C 1 3 , C1 4 ABC
Y±B
BR
Y±V L±B
L
G±O
Y±B
Y±B
Y±B
W±B
W±B 12
GR±R
GR±R
GR±R
GR±R WASHER
B
9
IE 1
10 IG1
18
1
EB
W1
WASHER LEVEL SW P±L
P±L
P±L
W±B
3H 1
G±O
TO A/T INDICATOR LIGHT
( FOR SHIFT LEVER )
ILLUMINATION I8
L
L
TO A/C AND AUDIO
ILLUMINATION
A
2 R9
WhereEverybodyKnowsYourName

223
COMBINATION METER
B 1 BRAKE FLUID LEVEL SW
1±2 : CLOSED WITH FLOAT DOWN
P 3 PARKING BRAKE SW
1±GROUND : CLOSED WITH PARKING BRAKE LEVER PULLED UP
O 2 OIL PRESSURE SW
1±GROUND : CLOSED WITH OIL PRESSURE BELOW APPROX. 0.2 KG/CM2 (2.8 PSI, 20 KPA)
W 3 WATER TEMP. SENDER
1±GROUND : APPROX. 226
(50 °C, 122 °F)
APPROX. 25
(11 5 °C, 239 °F)
E 6 ENGINE OIL LEVEL WARNING SW
1±2 : CLOSED WITH FLOAT UP AND ENGINE OIL TEMP. AT BELOW APPROX. 55°C ( 131 °F)
OPEN WITH FLOAT DOWN AND ENGINE OIL TEMP. AT BELOW APPROX. 60°C ( 140 °F)
F18(A) FUEL SENDER
2±3 : APPROX. 3
AT FUEL FULL
APPROX. 11 0
AT FUEL EMPTY
C14 (C) COMBINATION METER
1±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
12±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ST POSITION AND SHIFT LEVER AT P OR N RANGE
10±GROUND : ALWAYS CONTINUITY
22±GROUND : ALWAYS CONTINUITY
11±GROUND : ALWAYS APPROX. 12 VOLTS
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A1026E 626R 929
B 126F17B30S 327
C12A28F18A30S22B29
C13B28I 227S23A29
C14C28I16A29T1529
D 128O 227W 127
D 228P 329W 327
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
IE20INSTRUMENT PANEL WIRE
1G20COWL NO. 2 WIRE
1H
1I20COWL WIRE1J20COWL WIRE
1K
3A
3B
3C
3D22INSTRUMENT PANEL WIRE
3E
3F
3H
SERVICE HINTS
WhereEverybodyKnowsYourName

224
COMBINATION METER
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IE136ENGINE ROOM MAIN WIRE AND COWL WIRE (R/B NO. 4)
IG136INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)
IG338INSTRUMENT PANEL WIRE AND COWL WIRE (RIGHT KICK PANEL)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
IK136ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)IK236ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
IO138ENGINE ROOM MAIN WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
BU140FLOOR WIRE AND INSTRUMENT PANEL WIRE (LEFT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EA34FRONT SIDE OF RIGHT FENDER
EB34FRONT SIDE OF LEFT FENDER
ED34REAR SIDE OF CYLINDER HEAD RH
IF36LEFT KICK PANEL
IG36INSTRUMENT PANEL BRACE LH
BK40UNDER THE CENTER PILLAR LH
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
E2034ENGINE WIREI22
I 4I2338INSTRUMENT PANEL WIRE
I 738COWL WIREI39
38INSTRUMENT PANEL WIRE
I 8
WhereEverybodyKnowsYourName

26
ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
A 1 A/C Ambient Temp. Sensor E 1 ECT Solenoid
A 2 A/C Lock Sensor and A/C Magnetic Clutch E 2 EFI Water Temp. Sensor
A 3 A/C High Pressure SW E 3 EGR Gas Temp. Sensor (for USA Spec.)
A 4 ABS Actuator E 5 Engine Hood Courtesy SW
A 5 ABS Actuator (w/ Traction Control) E 6 Engine Oil Level Warning SW
A 6 ABS Actuator (w/ Traction Control)
A 7 ABS Speed Sensor Front LH F 1 Front Airbag Sensor LH
A 8 ABS Speed Sensor Front RH F 2 Front Airbag Sensor RH
A 9 Air Flow Meter F 3 Front Clearance Light LH
A 10 Alternator F 4 Front Clearance Light RH
A 11 Alternator F 5Front Side Marker Light LH
A 33 ABS Actuator (w/o Traction Control) F 6 Front Side Marker Light RH F 7 Front Turn Signal Light LH
B 1 Brake Fluid Level SW F 8 Front Turn Signal Light RH
B 6 Back±Up Light SW (for M/T) F 9 Fuse Block
C 3 Check Connector H 1 Headlight Hi LH
C 6 Cornering Light LH H 2 Headlight Hi RH
C 7 Cornering Light RH H 3 Headlight Lo LH
C 8 Cruise Control Actuator H 4 Headlight Lo RH H 5 Horn LH
D 13 Distributor H 6 Horn RH
WhereEverybodyKnowsYourName

27
Position of Parts in Engine Compartment
I 1 ISC Valve S 3Speed Sensor No. 1
I 2 Igniter S 4 Speed Sensor No. 2 (for ECT)
I 4 Ignition Coil S 6 Starter
I 6 Injector No. 1 S 7 Starter
I 7 Injector No. 2 S 8 Sub Throttle Actuator
I 8 Injector No. 3 S 9 Sub Throttle Position Sensor
I 9 Injector No. 4
I 10 Injector No. 5 T 1 Theft Deterrent Horn
I 11 Injector No. 6 T 2 Throttle Position Sensor T 3 Traction Brake Actuator
K 1 Knock Sensor No. 1 (on Front Side) T 4 Traction Brake Actuator
K 2 Knock Sensor No. 2 (on Rear Side) T 5 Traction pump and Motor
N 1 Neutral Start SW, Back±Up Light SW and A/T Indicator SW V 1 VSV (for EGR) (Exc. USA Spec) (for A/T) V 2 VSV (for EVAP)
N 2 Noise Filter (for Defogger System) V 4 VSV (for Water Valve)
N 3 Noise Filter (for Ignition System) V 7 VSV (for Intake Control Valve)
O 2 Oil Pressure SW W 1 Washer Level SW
O 3 Oxygen Sensor Main No. 1 (on Front Side) W 2 Washer Motor
O 4 Oxygen Sensor Main No. 2 (on Rear Side) W 3 Water Temp. Sender W 5 Wiper Motor
P 1 PPS Solenoid
P 20 Power Steering Pressure SW
WhereEverybodyKnowsYourName

28
ELECTRICAL WIRING ROUTING
Position of Parts in Instrument Panel
A 12 A/C Control Assembly C 9 CD Player
A 13 A/C Control Assembly C 10 Center Airbag Sensor Assembly
A 14 A/C Control Assembly C 11 Cigarette Lighter
A 15 A/C Control SW and Radio SW C 12 Combination Meter
A 16 A/C Evaporator Temp. Sensor C 13 Combination Meter
A 17 A/C Power Transistor C 14Combination Meter
A 18 A/C Power Transistor C 15 Combination SW
A 19 A/C Room Temp. Sensor C 16 Combination SW
A 20 A/C Solar Sensor C 17 Combination SW
A 21 A/T Indicator Light (for Shift Lever) C 19 Cruise Control ECU
A 22 ABS ECU (for M/T, w/o Traction Control) C 23 Clutch Start SW
A 23 ABS ECU (for M/T, w/o Traction Control) C 24 Cruise Control Clutch SW
A 24 ABS and Traction ECU
A 25 ABS and Traction ECU D 1 Diode (for Brake Fluid Level)
A 26 ABS and Traction ECU D 2 Diode (for Parking Brake)
A 27 Air Mix Control Servo Motor D 3 Diode (for Tension Reduser)
A 28 Air Vent Mode Control Servo Motor
A 29 Airbag Squib E 8 ECT Pattern Select SW
A 33 Air Inlet Control Servo Motor E 9 Engine and ECT ECU (for A/T) E 10 Engine and ECT ECU (for A/T)
B 2 Blower Motor E 11 Engine ECU (for M/T)
B 3 Blower Resistor (for Low Speed) E 12 Engine ECU (for M/T)
F 10 Fuel Lid Opener SW
G 1 Glove Box Light
G 2 Glove Box Light SW
WhereEverybodyKnowsYourName

35
CODEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
EB1ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO 2)EB2ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO. 2)
WhereEverybodyKnowsYourName