fog light LEXUS SC400 1991 Service User Guide

EG0B4±0K
ENGINE OIL INSPECTION
1. CHECK OIL QUALITYCheck the oil for deterioration, entry of water, discoloring or
thinning.
If oil quality is visibly poor, replace the oil.
Oil grade:
API grade SG or SH, Energy±Conserving II or ILSAC
multigrade engine oil. Recommended viscosity is as
shown in the illustration, with SAE 5W±30 being the
preferred engine oil.
Drain and refill capacity: w/ Oil filter change
4.8 liters (5.1 US qts, 4.2 lmp. qts)
w/o Oil filter change
4.5 liters (4.8 US qts, 4.0 lmp. qts)
2. CHECK ENGINE OIL LEVELThe oil level should be between the ªLº and ªFº marks on the
dipstick.
If low, check for leakage and add oil up to the ªFº mark.
EG3E2±01
BATTERY INSPECTION
1. CHECK BATTERY ELECTROYTE LEVEL AND VOLTAGE
(a) Check the electrolyte quantity of each cell.If under the lower level, replace the battery (or add distilled
water if possible.). Need to check the charging system.
(b) Measure the battery voltage between the terminals negative (±) and positive (+) of the battery.
Standard voltage:
12.7±12.9 V at 20 5C (68 5F)
HINT:
w Before measuring the voltage, turn the ignition switch
OFF and turn off the electrical systems (headlight,
blower motor, rear defogger etc.) for 60 seconds to
remove the surface charge.
EG±10
±
1UZ±FE ENGINE ENGINE MECHANICAL
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DEFOGGER SYSTEM
Description
The component parts of this system and their functions are described in the\
following table.
 Parts Name\
 \
Function
 Defogger\
 \
When over current flows in the defogger circuit, the Defogger fuse break\
s the circuit to pro-
tect it against damage.
 


Defogger Relay\
 
\

\

This relay is supplied with current from terminal IG1 of ignition switch\
(Ignition switch
ON) and switches large current from the defogger.
 


A/C Control Panel
Assembly

Defogger Switch\
 
\

\

The defogger switch is built into the A/C Control Panel Assembly. This switch is
supplied with current from the relay and fuse HTR. Grounds current from \
the defogger
relay, turning the defogger relay ON.
 




Defogger

Rear Window
 Outer Mirror\
 
\


\

\

These defoggers generate heat when current is supplied from the defogger\
relay.
Parts Location
±
BODY ELECTRICAL SYSTEM Lighting SystemBE±51
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(c) Turn the defogger switch ON and check that the test bulb andindicator light turn ON, then turn OFF after about 15 minutes.
If operation is not as specified, replace the air conditioner control
panel assembly.
(Defogger Relay)
INSPECTION OF DEFOGGER RELAY
INSPECT RELAY CONTINUITY AND OPERATION
If continuity is not as specified, replace the relay.
(Defogger Wires)
INSPECTION AND REPAIR OF
DEFOGGER WIRES
1. INSPECT DEFOGGER WIRESNOTICE:
w When cleaning the glass, use a soft, dry cloth, and wipe
the glass in the direction of the wire. Take care not to
damage the wires.
w Do not use detergents or glass cleaners with abrasive
ingredients.
w When measuring voltage, wind a piece of tin foil around
the top of the negative probe and press the foil against
the wire with your finger as shown.
(a) Turn the ignition switch ON.
(b) Turn the defogger switch ON.
(c) Inspect the voltage at the center of each heat wire as
shown.
 Voltage Criteria
Approx. 5 VOkay (No break in wire) Approx. 10 V or 0 V Broken wire
HINT: If there is approximately 10 volts, the wire is broken be-
tween the center of the wire and the positive (+) end. If there
is no voltage, the wire is broken between the center of the
wire and ground.
±
BODY ELECTRICAL SYSTEM Defogger SystemBE±53
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2HEAT METHOD: When the problem seems to occur when the suspect area is heate\
d.
Heat the component that is likely the cause of the mal-
function with a hair dryer or similar object. Check to see
if the malfunction will occur.
Notice:

Do not heat to more than 60 C (140 F) (Tempera-
ture limit that the component can be touched with a
hand.)

Do not apply heat directly to any part in the ECU.
3WATER SPRINKLING METHOD: When the malfunction seems to occur on a rainy day or in
a high±humidity condition.
Sprinkle water onto the vehicle and check to see if the
malfunction will occur.
Notice: Never apply water directly onto the
electronic components.
HINT:

If the vehicle is subject to water leakage, the leaked
water may contaminate the ECU. When testing a ve-
hicle with a water leakage problem, special caution
must be paid.
4OTHER: When a malfunction seems to occur when electrical load is excessive.
Turn on all electrical loads including the heater blower,
headlights, rear window defogger, etc. and check to see
if the malfunction will occur.
RS±66±
SUPPLEMENTAL RESTRAINT SYSTEM TROUBLESHOOTING
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YESNO
INSPECTION PROCEDURE
1Preparation.
P1. Turn ignition switch LOCK.
2. Disconnect battery negative (±) terminal cable, andwait at least 90 seconds.
3. Connect battery negative (±) terminal cable.
4. Disconnect center airbag sensor assembly con- nector.
5. Turn ignition switch ON. But do not start engine.
6. Measure voltage at IG
2 or ACC on connector wire
harness side of center airbag sensor assembly and
operate electric system (defogger, wiper, headlight,
heater blower, etc.)
Voltage: 6 V ± 11.5 V at IG
2 and ACC.
7. Turn electric system switch OFF.
8. Turn ignition switch LOCK.
9. Disconnect battery negative (±) terminal cable, and wait at least 90 seconds.
10. Remove voltmeter and connect center airbag sen- sor assembly connector.
11. Connect battery negative (±) terminal cable.
2Does SRS warning light turn off after approx. 10 seconds?
C
PTurn ignition switch ACC or ON and wait at least 20 sec-
onds.
Clear malfunction code. Turn ignition switch LOCK and
wait at least 20 seconds.
Operate electric system checked in
(5) and check
that SRS warning light goes off after approx. 10 sec-
onds.
Check diagnostic trouble code, and if a malfunction code
is output, perform trouble shooting according to mal-
function code. If a normal code is output, replace center
airbag sensor assembly.
Check battery and charging system.
(See page CH±1)
±
SUPPLEMENTAL RESTRAINT SYSTEM TROUBLESHOOTINGRS±69
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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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31
Position of Parts in Body
M 1 Mobilephone R 16 Remote Control Mirror LH
M 2 Moon Roof Control Relay R 17 Remote Control Mirror RH
M 3 Moon Roof Control SW R 18 Remote Control Mirror SW
M 4 Moon Roof Motor and Limit SWS 13 Stereo Power Amplifier
O 8 Oxygen Sensor Sub (for California) S 14 Stereo Power Amplifier
P 4 Power Window Control SW RH T 16 Telephone Transceiver and Speaker Relay
P 5 Power Window Master SW and Door Lock Control SW LH T 17 Telephone Transceiver and Speaker Relay
P 6 Power Window Motor LH T 18 Tension Reducer Solenoid LH
P 7 Power Window Motor RH T 19 Tension Reducer Solenoid RH
P 20 Personal Light V 5 Vanity Light LH
R 10 Rear Combination Light LH V 6 Vanity Light RH
R 11 Rear Combination Light RH
R 12 Rear Speaker LH W 8 Wireless Door Lock ECU
R 13 Rear Speaker RH W 9 Woofer Speaker
R 14 Rear Window Defogger (+) W 10 Woofer Speaker Amplifier
R 15 Rear Window Defogger (±)
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236
GROUND POINT
FRONT TURN SIGNAL
LIGHT LH
ENGINE HOOD
COURTESY SW
TRACTION PUMP AND
MOTOR
HEATER RELAY
ABS ACTUATOR RELAY
TELEPHONE
TRANSCEIVER
AND SPEAKER RELAY
ENGINE OIL LEVEL
WARNING SW
COMBINATION METER
(E1 )
EFI ECU
TRACTION ECU
CHECK CONNECTOR
(
E1 ) CORNERING LIGHT LH
FRONT SIDE MAKER
LIGHT LH
BRAKE FLUID LEVEL
SW
FRONT CLEARANCE
LIGHT LH
FRONT SIDE MAKER
LIGHT RH
FRONT CLEARANCE
LIGHT RH
ABS ACTUATOR
FRONT TURN SIGNAL
LIGHT RH
CRUISE CONTROL
ACTUATOR
OXYGEN SENSOR SUB
(
FOR USA SPEC. )
TDCL (
E1 )
WASHER LEVEL SW EFI MAIN RELAY
CORNERING LIGHT RH
A/C PRESSURE SW
(HI GH PRESSURE )
AIR FLOW METER POWER STERRI NG
PRESSURE SW
NOISE FI LTER
(
FOR IGNI TION SYSTEM ) E4
E10
E12 2
2
BS1 4 E4
E7
E1 E5
EB EA I23
I33
E1 6
I32
E20
E20
E20
IK2 24
ED EC IK1
1 BY1
5
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W± B W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B BR
BR
W±B BR
BR
BR
W±B BR
BR±B BR BR
BR
BR
W± B
W± B
W± B
W± B
W± B
W± B
W± B
W±B
W±B
BR
BR
BR
BR BR
BR
BR
W±B
BR BR
BR
( EO1 )
( E11 )
( E1 )
( EO2 )
I27BR
(
S1 )
( E1 )
NOISE FILTER (
FOR
IGNITION SYSTEM )W±B
W/ TRACTION SYSTEM
NOI SE FILTER
(
FOR DEFOGGER SYSTEM )
W±B
W±B
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1234
7 LEXUS SC300
4ACC
IG1
ST 1
AM1 2
1J
7 1J
5
1B
4 1E
72
74
6 1
2
4
5
3
2
1C
4
1A
7
2 3EB 6
5 12 IQ1 10 IQ1
11 IQ1
10 IG1 23 I G1
IG2
8
IG2 9
IE1
9
IQ23
IQ2 13
IQ2 8
1H
11 1H 7
4
4 4
4
4
12
43
1E
19 1E 14 1C 31A4
3A
1
1J
1 3G
3
1E
18
IF
BM EA 10
3D
6
1K
2 3
23 B
16 A 17 A
5756
6
3
10 8 9
4 WW
W± RR± B
R±W G±Y
G±B W± R
G±R
WWW±B
G±R
W±RR±B
R± W
R± WR±B
W± B
G±R B±Y
W
R± W R±B
R± W
R±B
R± B
R±W
W± B
R±B
R±W
G±Y G±Y G±B
G±B
W±B
W±B
W±B
W±B
W±B
W± B
W± B
W±B W±B G±B
G±Y
WW
W±L W
W
B± Y
60A MAIN
100A AM1
120A ALT
I15
IGNITION SW 20A
TURN
25A
HA Z± HORN
TURN SIGNAL FLASHER
BATTERY
F7
F RONT T URN S I GNA L
LIGHT LH
R1 0
REAR TURN SI GNAL LI GHT LH
[REAR COMB. LIGHT LH]
R11
REAR TURN SIGNAL LIGHT RH
[ REAR COMB. LIGHT RH] F8
F RONT T URN S I GNA L
LIGHT RH C1 6
TURN SI GNAL SW
[COMB. SW]
TURN SIGNAL INDICATOR
LIGHT[ COMB. METER]
OFF
ON B1 F B2TLTBTR
H7
HA ZA RD SW
B
FOD FOE
FOG FOF
1I
1
1I
2
55 55
2 1 5
3
18 IE1
17 I E1
1 2 1
2
EA
8
11
10
W± G
G± R
G± R
W± B
W± B
W±B R±G
P± Y
R±G
P± Y R± YTo I ntegrat ion Relay
<5±2><4±2>
CORNERI NG
LIGHT RELAY
C16
CONE RI NG L I GHT
SW[COMB. SW]CORNERI NG LI GHT
C6
LH C7
RH
F9
FUSE BLOCK
Power
Source
Cornering Light Turn Signal and Hazard Warning Light40A
IGSW TURN SIGNAL INDICATOR LIGHT
[COMB. METER]
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
AB
C13 C14
C13 A , C14 B
Front side of
r ight fender Fr ont side of
left fender Bac k panel
c enterFront side of
r ight fenderLeft kick
panel
6
5
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OVERALL ELECTRICAL WIRING DIAGRAM
1234
14 LEXUS SC300
1J
41J 7 1J
5
2
44
11
1B
4
441K
13 4 1A
52
22
3 1
4
2
3
2
4
1
5 22
13 IE1
2Bb1
10 IG2
16 IG1
3232
4
ACC
IG1
ST1
AM1 3
2
2 1
IF BL Bk EB
4Bb1
3H
14
1E
18 3A
1 11
3232 1B
1
1J
8
3A
5
1D
11H 4
1C
7 1E
2
3F
5
4IP2
10 Bc 2
20 IP1 4
1
2 2
IJ
BL
B
B
W± B
W
W± LB
WB
B
B
B±R
B
B
W± B
W± B
W± B
W±B
W± B
G
L
R± Y R± Y B
R± Y
W± B
W±B W±B W±B W±B
W± B L
G
GL
R±L
L±R B
L±R
L±R B
W± B
W± B W± B
W± B
W±B
W± B
L±R P±L
L±R B B
P±L
B± Y
B±Y
120A ALT 100A AM1F9
FUSE BOX4
3
I15
IGNITION SW
40A
IGSW 15A
ECU±I G
15A
SEAT±HTR
SEAT HEATAER SW
S18
SEAT HEATER RH
( f or Driver' s Seat Cushion )
S16
SEAT HEATER LH
( f or Pas senger ' s Seat Cus hion )SEAT HEATER
RELAY
W Y
W Y
W± B
To A/C Con tro l
Assembly< 22±7>
BATTERY
S1 7
SEAT HEAT ER RH
( for Driver' s
Se at Bac k )
S1 5
SEAT HEAT ER LH
( for Passenger' s
Se at Bac k )
DEFOGGER
RELAY
10A
HT R
50A
DEFOGGER 10A
MI R± HT R
4 3
LH
RH
MIRROR HEATER
[ REMOTE CONTROL MIRROR]
C22
CHOKE COI L
RE AR WI NDOW
DE FOGGE R
C11
CIGARETTE
LIGHTER
15A
CI G
N2
NOI SE
FILTER
( for Def ogger Syst em )
Power
Source Seat Heater
Rear Window Defogger and
Mirror HeaterCigarette
Lighter
6 54
Lef t kick panel Under t he center pillar
RHUnd er t he
center pillar
LHFr ont s ide of
left fender
Under the
center
pillar RHRight k ic k panel
2
1
1
1J 10
1D 8
3F 2Ba2
Ba1
14
5Ba2 Ba1
12 *
1
* 2
* 1
* 2
3 BY1 2 BU1
5B 7A
10 A 3 A3B 4B
1
B
8
A (
A/ T )
( M/ T )
(
A/T )
( M/T )
*2: (
w/ o Memory Power Seat )
*
1:
(
w/ Me mo r y P ower S ea t )
L
G
W±B (
* 3
)
8E 8E
5F
(
* 4
)
5F 4F 7E
( * 4)
4F
(
* 3)
7E (
* 3)
( * 4)
( * 3
)
( * 4
)
*
3: (
w/ Me mor y )
* 4: (
w/ o Memo r y )
9876 4321 5 54 21
3
E
R16, R17 F
R1 6, R17
MI RROR HE A TER
[ R EMOT E C ON RT OL MI RR OR ] MIRROR HEATER
[REMOTE CONRTOL
MIRROR]
123456
12 34
5 6 10 11 789B
(
A/T )
S24
A
(
M/T )
T12
S2 4 B , T1 2 A
SEAT HEATAER SW
1C
1D
R14 C , R15 D
(* 3) (
* 4 )
L
B
1
1
C
R14 D
R15
REAR WI NDOW DEFOGGER
R17
R1 6 E F
EF
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