1991 LEXUS SC300 oil

219
1E
2
IK1
6
I22
IHC
10
C
13 C 14 C 19 C20 C 16 C17 C18 C 6
412 97812
3A
5
3C
5
3F
6
L±R
L±R
V±R
RRR
V
V±W
B
R±Y W L±R
L±R
TRIP SW AND THEFT DETERRENT INDICATOR LIGHT 15A
CIG
TRIP METER
CIRCUIT
CLOCK SPEED
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
ENGINE OIL LEVEL
WARNING SW T15
C12 ,
3,C14
E6 COMBINATION METER
A
BC
OIL TEMP. OIL LEVEL
E20
W±B
ED C
15
A
1
B 2 AI39
SHORT CONNECTOR
,23
A
2 TO DOOR LOCK
CONTROL RELAY
L±R
W±B
BR
V±R
BR
BR
E2ACC
R
P
21
BR
BR
S22 BP
P
R
C1
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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
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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
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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
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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
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30
ELECTRICAL WIRING ROUTING
Position of Parts in Body
A 30 ABS Speed Sensor Rear LH D 10 Door Lock Motor, Door Unlock Detection SW and
A 31 ABS Speed Sensor Rear RH Door Open Detection SW LH
A 32 Auto Antenna Motor and Relay D 11 Door Lock Motor, Door Unlock Detection SW andDoor Open Detection SW RH
C 20 CD Automatic Changer D 12 Driving Position Memory and Return SW
C 21 CD Automatic Changer
C 22 Choke Coil F 11 Front Door Speaker LH F 12 Front Door Speaker RH
D 4 DAY/NIGHT Shift SW F 14 Fuel Lid Opener Solenoid
D 5 Door Courtesy Light LH F 15 Fuel Pump
D 6 Door Courtesy Light RH F 16 Fuel Pump ECU
D 7 Door Key Lock and Unlock SW LH F 17 Fuel Sender
D 8 Door Key Lock and Unlock SW RH F 18 Fuel Sender
D 9 Door Lock Control SW RH H 8 High Mount Stop Light (w/o Rear Spoiler)
H 9 High Mount Stop Light (w/ Rear Spoiler)
L 2 Licence Plate Light
L 3 Light Failure Sensor
L 4 Luggage Compartment Door Opener Motor
L 5 Luggage Compartment Key Unlock SW
L 6 Luggage Compartment Light SW
L 7 Luggage Compartment Light
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66
.
ENGINE CONTROL
THIS SYSTEM UTILIZES AN ECU AND MAINTAINS OVERALL CONTROL OF THE ENGINE, TRANSMISSION AND SO ON. AN OUTLINE O\
F
THE ENGINE CONTROL IS EXPLAINED HERE.
1. INPUT SIGNALS
(1) WATER TEMP. SIGNAL CIRCUITTHE WATER TEMP. SENSOR DETECTS THE ENGINE COOLANT TEMP. AND HAS A BUILT±IN THERMISTOR WITH A RESISTANCE
WHICH VARIES ACCORDING TO THE WATER TEMP. THE WATER TEMP. IS INPUT INTO TERMINAL THW OF ENGINE CONTROL
ECU AS A CONTROL SIGNAL.
(2) INTAKE AIR TEMP. SIGNAL CIRCUIT THE INTAKE AIR TEMP. SENSOR IS INSTALLED IN THE AIR FLOW METER AND DETECTS THE INTAKE AIR TEMP., WHICH IS INPUT
AS A CONTROL SIGNAL TO TERMINAL THA OF ENGINE CONTROL ECU.
(3) OXYGEN SENSOR SIGNAL CIRCUIT THE OXYGEN DENSITY IN THE EXHAUST EMISSION IS DETECTED AND INPUT AS A CONTR\
OL SIGNAL FROM THE OXYGEN
SENSOR NO. 1 AND NO. 2 TO TERMINALS OX1, OX2 OF THE ECU AND FROM THE OXYGEN SENSOR SUB (FOR CALIFORNIA) TO
TERMINAL OX3 OF THE ECU.
TO STABILIZE DETECTION PERFORMANCE BY THE OXYGEN SENSOR SUB (FOR CALIFORNIA)\
IS WARMED. THIS HEATER IS
ALSO CONTROLLED BY THE ECU (HT).
(4) RPM SIGNAL CIRCUIT CRANKSHAFT POSITION IS DETECTED BY THE PICK±UP COIL INSTALLED INSIDE THE DISTRIBUTOR. CRANKSHAFT POSITION
IS INPUT AS A CONTROL SIGNAL TO TERMINALS G1 AND G2 OF THE ECU, AND RPM IS INPUT TO TERMINAL NE.
(5) THROTTLE SIGNAL CIRCUIT THE THROTTLE POSITION SENSOR DETECTS THE THROTTLE VALVE OPENING ANGLE AS A CONTROL SIGNAL, WHICH IS
INPUT INTO TERMINAL VTA1 OF THE ECU. WHEN THE VALVE IS COMPLETELY CLOSED, THE CONTROL SIGNAL IS INPUT INTO
TERMINAL IDL1 .
(6) VEHICLE SPEED CIRCUIT THE VEHICLE SPEED IS DETECTED BY SPEED SENSOR NO. 1 INSTALLED IN THE TRANSMISSION AND THE SIGNAL IS INPUT TO
TERMINAL SPD OF THE ECU VIA THE COMB. METER.
(7) NEUTRAL START SIGNAL CIRCUIT THE NEUTRAL START SW DETECTS WHETHER THE SHIFT POSITION IS IN NEUTRAL OR NOT, AND THE SIGNAL IS INPUT INTO
TERMINAL NSW OF THE ECU.
(8) AIRCONDITIONING SW SIGNAL CIRCUIT THE OPERATING VOLTAGE OF THE A/C MAGNETIC CLUTCH IS DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL ACMG OF
ECU AS A CONTROL SIGNAL.
(9) BATTERY SIGNAL CIRCUIT VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ECU. WITH THE IGNITION SW TURNED ON, THE VOLTAGE FOR
ECU START±UP POWER SUPPLY IS APPLIED TO TERMINALS +B AND +B1 OF ECU VIA EFI MAIN RELAY.
THE CURRENT FLOWING THROUGH THE IGN FUSE FLOWS TO TERMINAL IGSW OF THE ECU.
(10) INTAKE AIR VOLUME SIGNAL CIRCUIT INTAKE AIR VOLUME IS DETECTED BY THE AIR FLOW METER AND THE SIGNAL IS INPUT TO TERMINAL KS OF THE ECU AS A
CONTROL SIGNAL.
(11) STOP LIGHT SW SIGNAL CIRCUIT THE STOP LIGHT SW IS USED TO DETECT WHETHER OR NOT THE VEHICLE IS BRAKING AND THE SIGNAL IS INPUT INTO
TERMINAL STP OF THE ECU AS A CONTROL SIGNAL.
(12) STA SIGNAL CIRCUIT TO CONFIRM WHETHER THE ENGINE IS CRANKING, THE VOLTAGE APPLIED TO THE STARTER MOTOR DURING CRANKING IS
DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL STA OF THE ECU AS A CONTROL SIGNAL.
(13) ENGINE KNOCK SIGNAL CIRCUIT ENGINE KNOCKING IS DETECTED BY KNOCK SENSOR NO. 1 AND NO. 2 AND THE SIGN\
AL IS INPUT INTO TERMINALS KNK1 AND
KNK2 AS A CONTROL SIGNAL.
SYSTEM OUTLINE
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METER, ANALOGCurrent flow activates a magnetic
coil which causes a needle to
move, thereby providing a relative
display against a background
calibration.
LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes
emit light without producing the
heat of a comparable light.
IGNITION COIL
Converts low±voltage DC current
into high±voltage ignition current
for firing the spark plugs.
1. SINGLE
FILAMENT
GROUND
The point at which wiring attaches
to the Body, thereby providing a
return path for an electrical circuit;
without a ground, current cannot
flow. Current flow causes a headlight
filament to heat up and emit light.
A headlight may have either a
single (1) filament or a double (2)
filament.
BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.
CAPACITOR (Condenser) A small holding unit for temporary
storage of electrical voltage.
CIRCUIT BREAKER Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it. Some
units automatically reset when cool,
others must be manually reset.
DIODE A semiconductor which allows
current flow in only one direction.
DIODE, ZENER A diode which allows current flow
in one direction but blocks reverse
flow only up to a specific voltage.
Above that potential, it passes the
excess voltage. This acts as a
simple voltage regulator.
FUSE A thin metal strip which burns
through when too much current
flows through it, thereby stopping
current flow and protecting a
circuit from damage.
FUSIBLE LINK A heavy±gauge wire placed in
high amperage circuits which
burns through on overloads,
thereby protecting the circuit.
The numbers indicate the cross±
section surface area of the wires. HORN
An electric device which sounds a
loud audible signal.
LIGHT Current flow through a filament
causes the filament to heat up
and emit light.
METER, DIGITAL Current flow activates one or
many LED's, LCD's, or fluorescent
displays, which provide a relative
or digital display.
MOTOR A power unit which converts
electrical energy into mechanical
energy, especially rotary motion.
CIGARETTE LIGHTER
An electric resistance heating
element.
DISTRIBUTOR, IIA Channels high±voltage current
from the ignition coil to the
individual spark plugs. 2. DOUBLE
FILAMENT
HEADLIGHTS
FUEL
(for High Current Fuse or
Fusible Link)
(for Medium Current Fuse)
M
16
GLOSSARY OF TERMS AND SYMBOLS
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