1991 LEXUS SC400 charging

SERVICE SPECIFICATIONS
SERVICE DATA
BatterySpecific gravity1.27±1.29
(when fully charged at 205C (68 5F))
AlternatorRated output12 V±100 A
Rotor coil resistance2.8±3.0

Slip ring diameterSTD 14.2±14.4 mm0.559±0567 in.
Limit 12.8 mm0.504 in.
Brush exposed lengthSTD 10.5 mm0.413 in.
Limit 1.5 mm0.059 in.
AlternatorRegulating voltageat 255C (77 5F)13.9±15.1 V
regulatorat 115 5C (239 5F)13.5±14.3 V
TORQUE SPECIFICATIONS
Part tightenedN Vmkgf Vcmft Vlbf
Alternator pulley X Rotor11 01,12581
Alternator X Alternator bracket37380 27
Alternator X Cylinder block3738027
±
CHARGING SYSTEM Service SpecificationsCH±21
WhereEverybodyKnowsYourName

When the vehicle is involved in a frontal collision in the
hatched area (Fig. 1) and the shock is larger than a predeter-
mined level, the SRS is activated automatically. A safing sen-
sor is designed to go on at a smaller deceleration rate than
the front and center airbag sensors. As illustrated in Fig. 2,
ignition is caused when current flows to the squib, which hap-
pens when a safing sensor and a front airbag sensor and/or
the center airbag sensor go on simultaneously. When a de-
celeration force acts on the sensors, two squibs in the driver
airbag and front passenger airbag ignite and generate gas.
The gas discharging into the driver and front passenger air-
bags rapidly increases the pressure inside the bags breaking
open the steering wheel pad and instrument panel door.
Bag inflation then ends, and the bags deflate as the gas is
discharged through discharge holes at the bag's rear or side.
RS±14±
SUPPLEMENTAL RESTRAINT SYSTEM OPERATION
WhereEverybodyKnowsYourName

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
WhereEverybodyKnowsYourName

203
WITH THE IGNITION SW TURNED ON, THE CURRENT FLOWS TO TERMINAL (A)14 OF THE WIPER AND WASHER SW, TERMINAL 2 OF
THE WASHER MOTOR AND TERMINAL 6 OF THE WIPER MOTOR THROUGH THE WIPER FUSE.
1. LOW SPEED POSITION
WITH WIPER SW TURNED TO LOW POSITION, THE CURRENT FLOWS FROM TERMINAL (A)14 OF THE WIPER AND WASHER SW "
TERMINAL (B)8 " TERMINAL 3 OF THE WIPER MOTOR " TERMINAL 1 " TO GROUND AND CAUSES TO THE WIPER MOTOR TO RUN
AT LOW SPEED.
2. HIGH SPEED POSITION
WITH WIPER SW TURNED TO HIGH POSITION, THE CURRENT FLOWS FROM TERMINAL (A)14 OF THE WIPER AND WASHER SW "
TERMINAL (A)7 " TERMINAL 2 OF THE WIPER MOTOR " TERMINAL 1 " TO GROUND AND CAUSES TO THE WIPER MOTOR TO RUN
AT HIGH SPEED.
3. INT POSITION
WITH WIPER SW TURNED TO INT POSITION, THE RELAY OPERATES AND THE CURRENT WHICH IS CONNECTED BY RELAY
FUNCTION FLOWS FROM TERMINAL (A)14 OF THE WIPER AND WASHER SW " TERMINAL (A)6 " TO GROUND . THIS FLOW OF
CURRENT OPERATES THE INTERMITTENT CIRCUIT AND THE CURRENT FLOWS FROM TERMINAL (A)14 OF THE WIPER AND
WASHER SW " TERMINAL (B)8 " TERMINAL 3 OF THE WIPER MOTOR " TERMINAL 1 " TO GROUND AND FUNCTIONS.
THE INTERMITTENT OPERATION IS CONTROLLED BY A CONDENSER'S CHARGED AND DISCHARGED FUNCTION INST\
ALLED IN
RELAY AND THE INTERMITTENT TIME IS CONTROLLED BY A TIME CONTROL SW TO CHARGE THE CHARGING TIME OF THE
CONDENSER.
4. MIST POSITION
WITH WIPER SW TURNED TO MIST POSITION, THE CURRENT FLOWS FROM TERMINAL (A)14 OF THE WIPER AND WASHER SW "
TERMINAL (B)8 " TERMINAL 3 OF THE WIPER MOTOR " TERMINAL 1 " TO GROUND AND CAUSES TO THE WIPER MOTOR TO RUN
AT LOW SPEED.
5. WASHER CONTINUOUS OPERATION
WITH WASHER SW TURNED TO ON, THE CURRENT FLOWS FROM TERMINAL 2 OF THE WASHER MOTOR " TERMINAL 1 "
TERMINAL (A)13 OF THE WIPER AND WASHER SW " TERMINAL (A)6 " TO GROUND AND CAUSES TO THE WASHER MOTOR TO
RUN. AND WINDOW WASHER IS JET. THIS CAUSES THE CURRENT TO FLOW WASHER CONTINUOUS OPERATION CIRCUIT IN
TERMINAL (A)14 OF THE WIPER AND WASHER SW " TERMINAL (B)8 " TERMINAL 3 OF THE WIPER MOTOR " TERMINAL 1 TO
GROUND AND FUNCTION.
C15(B), C16(A) WIPER AND WASHER SW [COMB. SW]
(A) 6±GROUND : ALWAYS CONTINUITY
(A) 14±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
(B) 8±GROUND : APPROX. 12 VOLTS WITH WIPER AND WASHER SW AT LOW OR MIST POSITION
APPROX. 12 VOLTS EVERY APPROX. 1 TO 10 SECONDS INTERMITTENTLY WITH WIPER SW AT INT POSITION
(B) 17±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON UNLESS WIPER MOTOR AT STOP POSITION
(A) 7±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON AND AFTER WIPER SW OFF UNTIL WIPER MOTOR STOPS
W 5 WIPER MOTOR
6±5 : CLOSED UNLESS WIPER MOTOR AT STOP POSITION
SYSTEM OUTLINE
SERVICE HINTS
WhereEverybodyKnowsYourName

60
CHARGING
1E
81H 52
3D
2 2
3D
1
IG3
1 IJ2
13 EB2 2
IJ1
5
A
A
A
231
LIG S B 1B
IC REGULATOR
6
11
57 1412
15
WB W B
W
B±O
Y±G
Y±G
Y±G
Y±G
Y±G B±Y W
B B±Y
W B±Y
W
B
FUSE B LOCK
BATTERY 7. 5A
IGN
7. 5A
ENGINE 7. 5A
ALT
SENCING
CHARGE W ARNING
LIG HT
[COMB . METER]
120A ALT
60A MAIN
A1 0 ,A11
A
B
ALTERNATOR
F9
C12
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
Y±G
TO INTE GRATION
RELAY
( CANADA )
I14
Y±G
WhereEverybodyKnowsYourName

OVERALL ELECTRICAL WIRING DIAGRAM
1234
1 LEXUS SC300 (
Cont . ne xt pa ge )
2 1
5
3
1J
7 1J
31J 5
3D
1
1B
4 1E
81H 52 2
3D
2
16 IE1
1EB2 15 IE1 3EB1
2
5IJ2 13IJ2 2EB2
1A B B
B
B
L
IG
S 1J
6
1K
4
1
C
1
D
4
ACC
IG1
ST1
IG2
AM1 2
1
6
11 AM2
15 14 2
2
2
1IG3
W
W± R B±Y
B±W
B± O
Y± G
B±YW
B
W± L
W
W± R
W± R
B
W
B±Y W
B
B B
B± W L±O
B B±O
B
B±W
Y± G
Y±G
Y±G
B± Y
W
B
B L±O
Y±G
B
W± R
4 7 9 14 13 5
6
120A ALT
100A AM1 30A I NJ
30A AM2
60A MAIN
F9
FUSE BL OCK
40A I GSW
I15
IGNITION SW
C12
CHARGE WARNING
LIGHT 7. 5A
ENGINE
7. 5A
AL T
SENCI NG
To Integr ation
Relay< 5±4> STARTER
RELAY
7. 5A
ST
N1
NEUTRAL
START SW
To Theft Deterrent
and Door Lock ECU
< 18±3>
To Engine and
ECT ECU< 2±2>
STARTER
AL TERNATOR
BATTERY
2
3
1
Charging Starting
B± O
Y± G
3
4
S6 D , S7 C
(Canada )
12
11
6IJ1
A1 0 B , A11 A 1
23 1
BA
A1 0 A11 BL ACKALTERNATOR 1
1
D
C
START ER
S6
S7 BROWN
Power Source
Y± G
2 1
IJ2 8B B
B± WB±W
(A/ T )
(
A/T )
(M/T )
(
M/T )
B C2 3
CL UTCH
START SW
B
2
3
P
N
B±O
B±O
WhereEverybodyKnowsYourName

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
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