code 32 LEXUS SC300 1991 Service Repair Manual

Q
R
S
T
U
V
W
X
7
:Explains the system outline.
: Indicates values or explains the function for reference during troublesh\
ooting.
: Indicates the reference page showing the position on the vehicle of the \
parts in the system circuit.
Example: Part ªP4º (Power Window Master SW) is on page 21 of the manual.
* The letter in the code is from the first letter of the part, and the number\
indicates its orderin parts starting with that letter.
Part is 4th in order
Power Window Master SW
Example: P
4
:
Indicates the reference page showing the position on the vehicle of Relay Block Connec\
tors in the
system circuit.
Example: Connector ª1º is described on page 16 of this manual and is installed on th\
e left side of the
instrument panel.
: Indicates the reference page showing the position on the vehicle of J/B and Wire H\
arness in the system
circuit.
Example: Connector ª3Bº connects the Cowl Wire and J/B No. 3. It is described on pag\
e 14 of this manual, and is installed on the instrument panel left side.
: Indicates the reference page describing the wiring harness and wiring harness connector (the female
wiring harness is shown first, followed by the male wiring harness).
Example: Connector ªID1ºconnects the front door RH wire (female) and cowl wire (ma\
le). It is described
on page 26 of this manual, and is installed on the right side kick panel.
: Indicates the reference page showing the position of the ground points o\
n the vehicle.
Example: Ground point ªICº is described on page 24 of this manual and is installed\
on the cowl left side.
: Indicates the reference page showing the position of the splice points on the veh\
icle.
Example: Splice point ªI 5º is on the Cowl Wire Harness and is described on\
page 24 of this manual.
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92
ILLUMINATION
TAILLIGHT RELAY5±3 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
C15 LIGHT CONTROL SW [COMB. SW]
3±4 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A1328E 828R 4A29
A1528F 926R 5B29
A2128G 128R 6C29
C1128G 228R 929
C12A28H 729T1229
C14B28I16A29T1529
C1528I16B29
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
1E20INSTRUMENT PANEL WIRE
1I
1J20COWL WIRE
1K
20COWL WIRE
3A
3C
3E22INSTRUMENT PANEL WIRE3F22INSTRUMENT PANEL WIRE
3G
3H
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IG136INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO.5)
IQ138INSTRUMENT PANEL WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PANEL CENTER)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I1838INSTRUMENT PANEL WIREI2938CONSOLE BOX WIRE
SERVICE HINTS
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96
INTERIOR LIGHT
INTEGRATION RELAY (J/B NO. 1)(1B) 5±GROUND : ALWAYS APPROX. 12 VOLTS
(1D) 8±GROUND : CONTINUITY WITH FRONT LH DOOR OPEN
(1I) 6±GROUND : CONTINUITY WITH FRONT RH DOOR OPEN
D10, D11 DOOR OPEN DETECTION SW LH, RH
3±6 : CLOSED WITH DOOR OPEN
L 6 LUGGAGE COMPARTMENT LIGHT SW
1±GROUND : CLOSED WITH LUGGAGE COMPARTMENT DOOR OPEN
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C12B28D1030L 730
C14A28D1130P2032
D 530I1430S1129
D 630I16A30V 531
D 730I16B30V 631
D 830L 630
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
422LEFT 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
1D20FRONT DOOR LH WIRE
1E20INSTRUMENT PANEL WIRE
1F20ROOF WIRE
1H
1I20COWL WIRE1J20COWL WIRE
1K
3A23INSTRUMENT PANEL WIRE3D23INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IF236ENGINE WIRE AND COWL WIRE (R/B NO. 4)
IP138FRONT DOOR RH WIRE AND COWL WIRE (RIGHT KICK PANEL)
BX140FLOOR NO. 3 WIRE AND COWL WIRE (RIGHT KICK PANEL)
Bc140FLOOR NO. 3 WIRE AND FLOOR WIRE (UNDER THE LEFT SIDE OF REAR SEAT CUSHION)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
IJ36RIGHT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I 6B 240ROOF WIRE
I 738COWL WIREB 440FRONT DOOR LH WIRE
I15
38COWL WIRE
B 640FRONT DOOR RH WIREB 140ROOF WIREB 740FRONT DOOR RH WIRE
SERVICE HINTS
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2
INTRODUCTION
This manual consists of the following 11 sections:No.
SectionDescription
A
INDEXIndex of the contents of this manual.
A
INTRODUCTIONBrief explanation of each section.
BHOW TO USE
THIS MANUALInstructions on how to use this manual.
CTROUBLE±
SHOOTINGDescribes the basic inspection procedures for electrical circuits.
DABBREVIATIONSDefines the abbreviations used in this manual.
E
GLOSSARY OF
TERMS AND
SYMBOLS
Defines the symbols and functions of major parts.
FRELAY LOCATIONSShows position of the Electronic Control Unit, Relays, Relay Block, etc.\
This section is closely related to the system circuit.
GELECTRICAL
WIRING ROUTINGDescribes position of Parts Connectors, Splice points, Ground points, etc.
This section is closely related to the system circuit.
HPOWER SOURCE
(Current Flow Chart)Describes power distribution from the power supply to various electrical
loads.
INDEXIndex of the system circuits.
I
SYSTEM CIRCUITS
Electrical circuits of each system are shown from the power supply through
ground points. Wiring connections and their positions are shown and
classified by code according to the connection method. (Refer to the
section, ªHow to use this manualº).
The ªSystem Outlineº and ªService Hintsº useful for troubleshoo\
ting are also
contained in this section.
JGROUND POINTSShows ground positions of all parts described in this manual.
KOVERALL
WIRING DIAGRAMProvides circuit diagrams showing the circuit connections.
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109
WITH THE IGNITION SW TURNED ON, THE CURRENT FLOWS TO TERMINAL 7 OF THE INTEGRATION RELAY THROUGH GAUGE
FUSE. VOLTAGE IS APPLIED AT ALL TIMES TO TERMINAL (A)4 (USA), (B)11 (CANADA) OF THE INTEGRATION RELAY THROUGH THE
TAILLIGHT RELAY COIL, AND TO TERMINAL (A)5 (USA), (B)12 (CANADA) THROUGH THE HEADLIGHT RELAY COIL.
1. NORMAL LIGHTING OPERATION
TURN TAILLIGHT ON
WITH LIGHT CONTROL SW TURNED TO TAILLIGHT POSITION, A SIGNAL IS INPUT INTO TERMINAL (A)3 (USA), (B)10 (CANADA) OF
THE INTEGRATION RELAY. DUE TO THIS SIGNAL, THE CURRENT FLOWING TO TERMINAL (A)4 (USA), (B)11 (CANADA) OF THE RELAY
FLOWS TO TERMINAL (A)3 (USA), (B)10 (CANADA) " TERMINAL 3 OF THE LIGHT CONTROL SW "TERMINAL 4 " TO GROUND AND
TAILLIGHT RELAY CAUSES TAILLIGHT TO TURN ON.
TURN HEADLIGHT ON
WITH LIGHT CONTROL SW TURNED TO HEADLIGHT POSITION, A SIGNAL IS INPUT INTO TERMINALS (A)3 (USA). (B)10 (CANADA)
AND (A)6 (USA), (B)13 (CANADA) OF THE INTEGRATION RELAY. DUE TO THIS SIGNAL, THE CURRENT FLOWING TO TERMINAL (A)5
(USA), (B)12 (CANADA) OF THE RELAY FLOWS TO TERMINAL (A)6 (USA), (B)13 (CANADA) " TERMINAL 13 OF THE LIGHT CONTROL
SW " TERMINAL 4 " TO GROUND IN THE HEADLIGHT CIRCUIT, AND CAUSES TAILLIGHT AND HEADLIGHT RELAY TO TURN ON. THE
TAILLIGHT CIRCUIT IS SAME AS ABOVE.
2. LIGHT AUTO TURN OFF OPERATION
WITH LIGHTS ON AND IGNITION SW TURNED OFF (INPUT SIGNAL GOES TO TERMINAL 7 OF THE RELAY), WHEN DOOR ON DRIVER'S
SIDE IS OPENED (INPUT SIGNAL GOES TO TERMINAL 6 OF THE RELAY), THE RELAY OPERATES AND THE CURRENT IS CUT OFF
WHICH FLOWS FROM TERMINAL (A)4 (USA), (B)11 (CANADA) OF THE RELAY TO TERMINAL (A)3 (USA), (B)10 (CANADA) IN TAILLIGHT
CIRCUIT AND FROM TERMINAL (A)5 (USA), (B)12 (CANADA) TO TERMINAL (A)6 (USA), (B)13 (CANADA) IN HEADLIGHT CIRCUIT.
AS A RESULT, ALL LIGHTS ARE TURNED OFF AUTOMATICALLY.
HEADLIGHT RELAY 1±2 : CLOSED WITH LIGHT CONTROL SW AT HEAD POSITION OR DIMMER SW AT FLASH POSITION
TAILLIGHT RELAY 5±3 : CLOSED WITH LIGHT CONTROL SW AT TA I L OR HEAD POSITION
I16(A)(B) INTEGRATION RELAY
7±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
6±GROUND : CONTINUITY WITH DOOR LH OPEN
(A) 4, (B) 11±GROUND: ALWAYS APPROX. 12 VOLTS
(A) 5, (B) 12±GROUND: ALWAYS APPROX. 12 VOLTS
(A) 6, (B) 13±GROUND: CONTINUITY WITH LIGHT CONTROL SW AT HEAD POSITION
(A) 3, (B) 10±GROUND: CONTINUITY WITH LIGHT CONTROL SW AT TA I L OR HEAD POSITION
D10 DOOR LOCK MOTOR, DOOR UNLOCK DETECTION SW AND DOOR OPEN DETECTION SW LH
3±6 : CLOSED WITH DOOR LH OPEN
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C1528F 926I16B29 (CANADA)
D1030I16A29 (USA)
: 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
1D20FRONT DOOR LH WIRE
1J20COWL WIRE1K20COWL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IE136ENGINE WIRE AND COWL WIRE (R/B NO.4)
SYSTEM OUTLINE
SERVICE HINTS
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11 0
LIGHT AUTO TURN OFF
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I 538COWL WIRE
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1
2
X
X X
910
D4 I15
BLACK
107
LIQUID CRYSTAL INNER REAR VIEW MIRROR
2
1F
8 1B
5 B212
RY
R
R
R
W± B
10A
DOME
FROM POWER SOURCE
SYSTEM(
SEE PAGE 56 )
INNER MIRROR UNLOCK
WARNING SW
[IGNITION SW]
D4 I15
TO FRONT PERSONAL
LIGHT
DAY/NIGHT
SHIFT SW 1F
9
1I
15
9
10
1H
13
1J
1
1F
YW±B
1 2
D 4 DAY/NIGHT SHIFT SW
1 ± GROUND: ALWAYS APPROX.
12 VOLTS
I15 UNLOCK WARNING SW [IGNITION SW]
10±9: CLOSED WITH IGNITION KEY IN CYLINDER
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
D 430I1529
: 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
1F20ROOF WIRE
1H
1I20COWL WIRE
1J
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
B 240ROOF WIRE
SERVICE HINTS
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199
6. TILT UP REMINDER SYSTEM
WITH THE IGNITION SW IS TURNED TO ACC OR OFF WITH THE MOON ROOF STILL TILTED UP, KEY OFF MOON ROOF OPERATION
CAUSES CURRENT TO FLOW TO TERMINAL 6 OF THE MOON ROOF CONTROL RELAY FOR A PERIOD OF APPROX. 60 SECONDS OR
UNTIL THE DRIVER'S DOOR OR PASSENGER'S DOOR IS OPENED. WHEN KEY OFF MOON ROOF OPERATION ENDS AND THE
CURRENT FLOW IS STOPPED, THE MOON ROOF CONTROL RELAY RECEIVES A SIGNAL THAT THE IGNITION SW IS OFF. MOON
ROOF LIMIT SW NO. 1 AND NO. 2 ARE OFF AT THIS TIME, SO THE SIGNAL IS INPUT TO TERMINALS 8 AND 9 OF THE MOON ROOF
CONTROL RELAY, INDICATING THAT THE MOON ROOF IS IN THE TILT UP CONDITION. THIS CURRENT TO THE MOON ROOF
CONTROL RELAY FLOWS TO TERMINAL 12 OF RELAY " BUZZER " TERMINAL 11 " GROUND, CAUSING THE BUZZER TO SOUND
FOR APPROX. 8 SECONDS. TO INFORM THE DRIVER THAT THE MOON ROOF IS IN THE TILT UP POSITION.
POWER MAIN RELAY
3±5 : CLOSED WITH IGNITION SW AT ON POSITION
M 2 MOON ROOF CONTROL RELAY
11±GROUND : ALWAYS CONTINUITY 6±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
4±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON, AND MOON ROOF CONTROL SW AT CLOSE OR UP POSITION
(EXCEPT APPROX. 200MM (7.9 IN) BEFORE FULLY CLOSED POSITION)
5±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON, AND MOON ROOF CONTROL SW AT OPEN OR DOWN POSITION
M 3 MOON ROOF CONTROL SW
1±4 : CLOSED WITH MOON ROOF CONTROL SW AT UP POSITION
2±4 : CLOSED WITH MOON ROOF CONTROL SW AT CLOSE POSITION
3±4 : CLOSED WITH MOON ROOF CONTROL SW AT DOWN POSITION
5±4 : CLOSED WITH MOON ROOF CONTROL SW AT OPEN POSITION
4±GROUND : ALWAYS CONTINUITY
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
D1030M 331T 8B29
D1130M4A31T 9A29
M 231M 4B31
: 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
1D20FRONT DOOR LH WIRE
1F20ROOF WIRE
1H
1I20COWL WIRE1J20COWL WIRE
1K
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IP138FRONT DOOR RH WIRE AND COWL WIRE (RIGHT KICK PANEL)
BZ140ROOF WIRE AND MOON ROOF WIRE (FRONT SIDE OF ROOF LEFT)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
IJ36RIGHT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
B 140ROOF WIREB 340MOON ROOF WIRE
SERVICE HINTS
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Junction Block (the number in the circle is the
J/B No. and connector code is shown beside
it). Junction Blocks are shaded to clearly
separate them from other parts (different
junction blocks are shaded differently for fur-
ther clarification.).
Example:
Indicates related system.
Indicates the wiring harness and wiring har-
ness connector. The wiring harness with male
terminal is shown with arrows
Outside numerals are pin numbers.
is used to indicate different wiring and
connector, etc. when the vehicle model, engine
type, or specification is different.
Indicates a shielder cable.
Indicates and located on ground point.
The same code occuring on the next page
indicates that the wire harness is continuous.
System Title
Indicates the wiring color.
Wire colors are indicated by an alphabetical
code.
B = Black L = Blue R = Red
BR = Brown LG = Light Green V = Violet
G = Green O = Orange W = White
GR = Gray P = Pink Y = Yellow
The first letter indicates the basic wire color and the
second letter indicates the color of the stripe.
Indicates the connector to be connected to a
part (the numeral indicates the pin No.)
The position of the parts. is the same as shown
in the wiring diagram and wire routing.
Indicates the pin number of the connector.
The numbering system is different for female
and male connectors.
The numbering system for the overall wiring
diagram is the same as above.
Indicates a Relay Block. No Shading is used
and only the Relay Block No. is shown to distin-
guish it from the J/B.
243
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46
POWER SOURCE (Current Flow Chart)*1: USA
*2: CANADA
60
216
226
192178
226 90 144 134 216 102 202
208
212 90
167
A2 A15 C6 B2
B1
A10 A14 A12 A17A13 A23 A24 A25 A32 C11 B3 B4 B6 C3 C10C7
A21
Blower Resistor Auto Antenna Motor
And Relay A/C Magnetic Clutch
Alternator
A/C Control Assembly
A/C Power Transistor
A/T Indicator Light
(for Shift Lever) A/C Control SW and
Radio SWABS ECU
ABS and Traction ECUBrake Fluid Level SW
Blower Motor
Center Airbag Assembly Check Connector
Cornering Light LH
Cigarette Lighter Back±Up Light SW Buckle SW LHABS and Traction ECUCornering Light RH
190
226 22690
126
226 10168
134
144
178


* These are the page numbers of the first page on which the related system\
is shown.
The part indicated is located somewhere in the system, not necessarily o\
n the page indicated here. *Page Nos. of
Related Systems
Parts
Code or
Location
CB or Fuse
50A DEFOG
30A DOOR
30A POWER
15A STOP
15A ECU±B
10A MIR±HTR
10A HEATER
20A TURN
20A WIPER
10A GAUGE
15A ECU±IG
7.5A ENGINE
7.5A IGN
15A CIG
7.5A RADIO No.2
15A TAIL
7.5A PANEL
7.5A ST
15A TEL
10A DOME
20A RADIO No.1
25A HAZ±HORN
30A EFI
7.5 ALT SENCING
15A HEAD LH*1
15A HEAD RH*1
15A HEAD LH±LWR*2
15A HEAD RH±LWR*2
15A HEAD LH±UPR
15A HEAD RH±UPR
60A HEATER
7.5A TRAC
15A SEAT±HTR
Location
[LOCATION](1): J/B No. 1 (See page 20)(2): R/B No. 2 (See page 19)(3): R/B No. 4 (See page 23)
20
19 22
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