ect LEXUS SC300 1991 Service Repair Manual

72
ENGINE CONTROL
VC
VTA
IDL
E2
2
134
12 34
E20 E18 E18
B
42
VTA2 B
63
IDL2 B
65
E2 B
64
IDL1 B
43
VTA1 B
41
VC B
45
THA B
66
KS
A
35 PS
B
47 OX2 5
THA KS VC
E2
BR BR
B±R
B±R
WGB
L±Y
B±R
BR
BR
BR
BR
BR R
Y
L±R
BR
Y±B
Y±G L±R
BR
R
Y
L±R BR
R±B
Y±L
E
THROTTLE
POSITION
SENSOR AIR FLOW METER
ENGINE ECU (
M/T )
TO S UB THROTTL E
POSITION SENSOR
(
W/ TRACTI ON
CONTROL )
E11 , E1 2
AB
T2
A9
ENGINE AND ECT ECU (
A/T )
E9 ,E10
A
B
(
FOR USA SPEC. )
1 2 I34
I40I17
I23 I32 B17
E16 I13
I34
I32
IK1 1
BY16
BY1
5
IG33
IK 2
22 IK2 12 BY1 2
BY1
1
1
1 B
48 OX1
B
71 HT
B
61 OX3
EC
BT1
17
LG±B
W
BR
W
BR±W
BR±W W
BR±W
W
R±L
R±L R±L
B±R
BR
B±R
( SHIELDED )
(
SHIELDED )
(
SHIELDED )
W
BR±W
R±B
BR BR BR R±L
G B
L±Y
B±R
BR
BR
BR
BR
(SHIELDED )
G
B
L±Y
B±R BR BR B±R
BR
R±L
BR±W
BR
OXYGEN SENSOR SUB
(FOR USA SPEC. )
O8
42 13
(
*2 )
(
*1 )
(
*2 )(
*1 )
(
*3 )
O3
OXYGEN SENSOR
MAIN NO. 1
(
ON FRONT SIDE )
POWER STERRING
PRESSURE SW P20
O4
OXYGEN SENNSOR
MAIN NO. 2
( ON REAR SIDE )
(
SHIELDED )
(
*3 )
R±L
B±R
B±R
BR
BR (*2 )
( *1 )
BR
( SHIELDED )
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73
* 1 : W/ CD PLAYER
* 3 : FOR USA SPEC. *2:W/OCDPLAYER
8 13 715 2
3411912 8 3
E20 I32
I32
IJ 1 1 IK1
3
IK1
4
IK1
5IK1 2
EB1
2II1 5
B
4 E11
B
69 E1
B
28 VF2
B
29 VF1
A
20 TE1
A
3 KD
A
17 TT
A
23
ACMG A
34
A/C
IF
ED
BR
WGB
L±Y
B±R BR
B±R B±R
B±RLG
GR±Y
W
L±O
L±R W
GR±Y LG
GR±Y LG
B±Y BR
GR±Y LG
G±R
G±Y G±R
L
BR
L±Y B±R
B
G
W
BR
W
E1
+B
IG±
FP
OX
E1
OX2 TE1 VF1 ENG TE1 TT TE2 E11 , E1 2
T6
C3
FROM A/C MAGNETIC
CLUTCH RELAY
FROM A/C CONTROL
ASSEMBLY
ENGINE ECU (
M/T )
CHECK CONNE CTOR TDCL
(TOTAL DIAGNOSTIC
COMMUNICATION LINK )
A
B
IJ 1 12
R±L
I33
I32
BR
15 VF2
14
BR
BR
EC
E9 ,E10
ENGINE AND ECT ECU
(
A/T )
AB
IH1
2 IJ2
17
1 2IH1
1
A
19 TE 2
G±Y
W±B W±B L L
( SHIELDED )
(
SHIELDED )
B±R
BR B±R
(
SHIELDED )
KICK DOWN
SW
K3
BR
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74
ENGINE CONTROL
EFI MAIN RELAY2 ± 4: CLOSED WITH IGNITION SW AT ON OR ST POSITION
W 4 WATER TEMP. SENSOR
1 ± 2: APPROX. 16.2K (±20 °C, ±4°F)
: APPROX. 2.45K (20 °C, 68°F)
: APPROX. 0.32K (80 °C, 176 °F)
E 3 EGR GAS TEMP. SENSOR (FOR USA SPEC.)
1 ± 2: APPROX. 78.30K (50 °C, 122 °F)
APPROX. 13.06K (100 °C, 212 °F)
APPROX. 3.16K (150 °C, 302 °F)
E 9(A), E10(B) ENGINE AND ECT ECU, E11(A), E12(B) ENGINE ECU
(VOLTAGE AT ENGINE AND ECT ECU WIRING CONNECTORS)
BATT ± E1 : ALWAYS APPROX. 12 VOLTS
IGSW ± E1 : APPROX. 12 VOLTS WITH IGNITION SW ON
+B, +B1 ± E1 : APPROX. 12 VOLTS WITH IGNITION SW ON
VC ± E2 : 4±6 VOLTS WITH IGNITION SW ON
IDL1, IDL2 ± E2 : 0±1 VOLTS WITH IGNITION SW ON AND THROTTLE VALVE FULLY CLOSED
: 10±14 VOLTS WITH IGNITION SW ON AND THROTTLE VALVE FULLY OPEN
VTA1, VTA2 ± E2 : 0.1±1.0 VOLTS WITH IGNITION SW ON AND THROTTLE VALVE FULLY CLOSED
: 3±6 VOLTS WITH IGNITION SW ON AND THROTTLE VALVE FULLY OPEN
THA ± E2 : 1±3 VOLTS WITH IGNITION SW ON AND INTAKE AIR TEMP. 20°C ( 68°F)
THW ± E2 : 0.1±1.0 VOLTS WITH IGNITION SW ON AND COOLANT TEMP. 80°C ( 176 °F)
STA ± E1 : 6±14 VOLTS WITH ENGINE CRANKING
#10, #20, #30, #40, #50, #60 ± E1 : APPROX. 12 VOLTS WITH IGNITION SW ON
IGF ± E1 : 0±1 VOLTS WITH ENGINE IDLING
MREL ± E1 : APPROX. 12 VOLTS WITH IGNITION SW ON
DI ± E1 : 7.5±14 VOLTS WITH ENGINE IDLING
ISC1, ISC2, ISC3, ISC4 ± E1 : APPROX. 12 VOLTS WITH IGNITION SW ON
HTL1, HTR1, HTL2, HTR2 ± E01 : 0±2 VOLTS WITH ENGINE IDLING
EGR ± E1 : APPROX. 12 VOLTS WITH ENGINE IDLING
NSW ± E1 : 0±1 VOLTS WITH IGNITION SW ON AND SHIFT LEVER P OR N RANGE
: 10±14 VOLTS WITH IGNITION SW ON AND SHIFT EXCEPT P OR N RANGE
TE1 ± E1 : APPROX. 12 VOLTS WITH IGNITION SW ON
TE2 ± E2 : APPROX. 12 VOLTS WITH IGNITION SW ON
W ± E1 : APPROX. 12 VOLTS WITH ENGINE IDLING
0±2 VOLTS WITH IGNITION SW ON
A/C ± E1 : 0±2 VOLTS WITH AIR CONDITIONER ON
10±14 VOLTS WITH AIR CONDITIONER OFF
ACMG ± E1 : 0±2 VOLTS WITH AIR CONDITIONER ON
: 10±14 VOLTS WITH AIR CONDITIONER OFF
TR ± E1 : APPROX. 12 VOLTS WITH IGNITION SW ON
VTA1, VTA2 ± E2 : 0±1 VOLTS WITH IGNITION SW ON AND THROTTLE VALVE FULLY CLOSED
3±5.5 VOLTS WITH IGNITION SW ON AND THROTTLE VALVE FULLY OPEN
NE ± E1 : 4±6 VOLTS WITH IGNITION SW ON
(RESISTANCE OF ENGINE AND ECT ECU WIRING CONNECTORS)
+B, +B1 ± #10, #20, #30, #40, #50, #60 : 13.2±14.2
+B, +B1, ISC1, ISC2, ISC3, ISC4 : 10±30
+B, +B1 ±EGR: 33±39
+B, +B1, HT : 5.1±6.3
+B, +B1 ±EVAP : 30±34
IDL1, IDL2 E2 : INFINITY WITH THROTTLE VALVE OPEN 0±0.5WITH THROTTLE VALVE FULLY CLOSED
VTA1, VTA2 E2 : 2.4±10.7WITH THROTTLE VALVE FULLY OPEN
0.3±5.9 WITH THROTTLE VALVE FULLY CLOSED
VCC ± E2 : 3±7K
THW ± E2 : 200±400 WITH COOLANT TEMP. 80°C ( 176 °F)
THA ± E2 : 2±3K WITH INTAKE AIR TEMP. 20°C ( 68°F)
THG ± E2 : 69.4±88.5K WITH EGR GAS TEMP. 50°C ( 11 2 °F)
G1, G2 ±G± : 0.835±13.5K
NE± G± : 0.835±13.5K
SERVICE HINTS
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75
I 1 ISC VALVE
4, 6±5 : APPROX. 21.3
1, 3±2 : APPROX. 21.3
I 6, I 7, I 8, I 9, I10, I11 INJECTOR
1 ± 2 : APPROX. 13.8
O 8 OXYGEN SENSOR SUB (FOR USA SPEC.)
1 ± 2 : APPROX. 5.6(20 °C, 68°F)
T 2 THROTTLE POSITION SENSOR
1 ± 4 : APPROX. 3±7K
1 ± 3 : 2.4±10.7 K WITH THROTTLE VALVE FULLY OPENED POSITION
0.3±5.9 K WITH CLEARANCE BETWEEN LEVER AND STOP SCREW 0MM (0 IN.)
1 ± 2 : LESS THAN 0.5K WITH CLEARANCE BETWEEN LEVER AND STOP SCREW 0.4 MM (0.0157 IN.)
INFINITY WITH CLEARANCE BETWEEN LEVER AND STOP SCREW 0.85MM (0.0335 IN.)
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76
ENGINE CONTROL
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A 926F1530K 329
C 326F1630N 127C13B28I 127O 327
C14A28I 227O 427C2328I 627O 831
D1326I 727P2027E 226I 827S 327
E 326I 927S1229E 9A28I1027T 227
E10B28I1127T 629E11A28I1529V 127
E12B28K 127V 227F 926K 227V 327
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
423LEFT KICK PANEL (J/B NO.1 LEFT)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
1E20INSTRUMENT PANEL WIRE1H1I20COWL WIRE1J20COWL WIRE
1K3A23INSTRUMENT PANEL WIRE3D23INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
EB134ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO 2)EB234ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO.2)
IE136ENGINE ROOM MAIN WIRE AND COWL WIRE (R/B NO. 4)
IG236INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)IG338INSTRUMENT PANEL WIRE AND COWL WIRE (RIGHT KICK PANEL)
IH136COWL NO. 2 WIRE AND COWL WIRE (BEHIND COMBINATION METER)II136ENGINE WIRE AND A/C WIRE (BEHIND GLOVE BOX)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)IJ236ENGINE 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)
BT140FLOOR WIRE AND COWL WIRE (LEFT KICK PANEL)BY140INSTRUMENT PANEL WIRE AND FLOOR NO.3 WIRE (RIGHT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EB34FRONT SIDE OF LEFT FENDER
EC34FRONT SIDE OF INTAKE MANIFOLDED34REAR SIDE OF CYLINDER HEAD RH
IF36LEFT KICK PANELIH36UNDER THE ASHTRAY LH
BK40UNDER THE CENTER PILLAR LH
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194
ELECTRIC TENSION REDUCER
1C
6 1I
8
Bb1
7
BX1
18
Bb1
4
BK BL
2 1
2
1
11
12 15 16
22
9
2 1 B±R
B±R
B
B±R
B
B
B±L
B±L
B±Y
BR
W±B
W±B
W±B
W±B
15A
ECU±IG
TE NSI ON
RE DUCER
SOLENOID LH TENSION
RE DUCER
SOLENOID RH
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
DIODE
( FOR TENSION
REDUCER )
POWER SEAT ECU
(FOR PASSENGER' S SEAT )
BUCKLE
SW LH BUCKLE
SW RHPC SSR± GND
PD
T1 8 T19
D3 P12
B4 B5
Ba2
6 Ba1
11
12
Ba2
5 (
W/ MEMORY POWER SEAT )
( W/O MEMORY POWER SEAT )
Ba1 (W/O MEMORY POWER SEAT )
(
W/ MEMORY POWER SEAT )
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195
B 4 BUCKLE SW LH
1±2 : CLOSED WITH DRIVER'S LAP BELT IN USE
B 5 BUCKLE SW RH
1±2 : CLOSED WITH PASSENGER'S LAP BELT IN USE
T18, T19 TENSION REDUCER SOLENOID LH, RH
2±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
B 432D 328T1831
B 532P1232T1931
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1C20FLOOR WIRE
1I20COWL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
BX140FLOOR NO. 3 WIRE AND COWL WIRE (RIGHT KICK PANEL)
Ba142FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)Ba242FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)
Bb142FLOOR NO. 3 WIRE AND FRONT SEAT RH WIRE (UNDER THE FRONT RH SEAT)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
BK40UNDER THE CENTER PILLAR LH
BL40UNDER THE CENTER PILLAR RH
12 12
X
912X1516X 12
B 4, B 5 D 3 P 12 T18, T19
ORANGE BLACK
SERVICE HINTS
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1
FOREWORD
This wiring diagram manual has been prepared to provide
information on the electrical system of the 1992 LEXUS SC300.
Applicable models: JZZ31 Series
For service specifications and repair procedures of the above
models other than those listed in this manual, refer to the
following manuals;
Manual Name
Pub. No.
1992 LEXUS SC300 Repair Manual
Volume 1
Volume 2
 1992 LEXUS New Car Features
RM260U1
RM260U2
NCF080U
All information in this manual is based on the latest product
information at the time of publication. However, specifications
and procedures are subject to change without notice.
TOYOTA MOTOR CORPORATION
Servicing vehicles with an SRS AIRBAG (referred to as the airbag in the
remainder of this manual) installed.
When handling airbag components (removal, installation or inspection, etc.)\
,
always follow the directions given in the repair manuals listed above to
prevent the occurrence of accidents and airbag malfunction.
NOTICE
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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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17
1. NORMALLYOPENOpens and
closes circuits,
thereby
stopping (1) or
allowing (2)
current flow.
RESISTOR An electrical component with a
fixed resistance, placed in a circuit
to reduce voltage to a specific
value.
RESISTOR, TAPPED A resistor which supplies two or
more different non±adjustable
resistance values.
SENSOR (Thermistor) A resistor which varies its
resistance with temperature.
SHORT PIN Used to provide an unbroken
connection within a junction block.
SOLENOID An electromagnetic coil which
forms a magnetic field when
current flows, to move a plunger,
etc. SWITCH, DOUBLE THROW
A switch which continuously
passes current through one set
of contacts or the other.
SWITCH,
IGNITION A key operated switch with
several positions which allows
various circuits, particularly the
primary ignition circuit, to
become operational.
Wires are always
drawn as straight lines
on wiring diagrams.
Crossed wires (1)
without a black dot at
the junction are not
joined; crossed wires
(2) with a black dot or
octagonal (
) mark at
the junction are spliced
(joined) connections.
RELAY, DOUBLE THROW
A relay which passes current
through one set of contacts or the
other.
SENSOR, ANALOG SPEED Uses magnetic impulses to open
and close a switch to create a
signal for activation of other
components. TRANSISTOR
A solidstate device typically used
as an electronic relay; stops or
passes current depending on the
voltage applied at ªbase.º
SWITCH, WIPER PARK
Automatically returns wipers to
the stop position when the wiper
switch is turned off.
SWITCH, MANUAL SPEAKER
An electromechanical device
which creates sound waves from
current flow.
2. NORMALLY CLOSED
RESISTOR, VARIABLE OR
RHEOSTAT A controllable resistor with a
variable rate of resistance.
Also called a potentiometer or
rheostat.
2. NORMALLY
OPEN
RELAY
1. NORMALLY
CLOSED Basically, an electrically
operated switch which may
be normally closed (1) or
open (2).
Current flow through a
small coil creates a
magnetic field which either
opens or closes an
attached switch.
(2) SPLICEDWIRES
(1) NOT CONNECTED
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