LEXUS SC400 1991 Service Repair Manual

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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108
LIGHT AUTO TURN OFF
1K
11
2 2
1D
8
IF
1J
1 1K
5
1B
2
2
1B
5
4
4
4 B
11
A
3A 6
B
12
1D10
6
4
2
47
3124
3
313
6
13
1
IE1
6 10A
GA UGE
10A
DOME
R±Y
W
W±B
R±W
W±B
W±B
R±GG±L W
W±LW
W±G
R±Y R±Y
W±L
R
G±W
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
BATTERY
FUSE BLOCK INTEGRATION
RE LAYTAILLIGHT
RELAY
HEADLIGHT
RELAY
FROM CORNERING
LIGHT RELAY
TO DIMMER SW
LIGHT
CONTROL SW
DOOR OPEN
DE TE CTION SW LH 120A ALT
100A AM1 60A MAIN
Q
Q S
R
R S
OFF
TAIL
HEAD
COMB INATION SW
F9
C15
D10
I16
DIODE 32 51
B
A
R±Y
7
A
4
B
10 B 13
A
5
R±Y
(CANA DA )
(
USA )
( USA )
( CANADA ) 2
I5 1
10 6
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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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196
MOON ROOF
1B
5
1I
16
1K
71K 13 2
1D
8 1F
8
1H 10
IP1
20 IP1
15
BZ1
4
BZ1
5 BZ1
1
IJ IF B3
B1
6 3
6
3
M
R
Y±R
W±B
W±B
W±B
W±B
W±B L
R
L±W
B±R
R
Y±R
W±B
R±B
R±W
R±W
R±W
W±B
W±B
B
BR
LG W
W±Y
W±B
B
W±B
W±B B±Y
11 4 5 8 9 12
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
30A
DOOR 15A
ECU±IG10A
DOME
THEFT DETERRENT AND
DOOR LOCK CONTROL E CU
KEY OFF POWER
CIRCUIT
DOOR OPEN DETECTION SW LH
DOOR OPEN DETECTION SW RH
MOON ROOF MOTOR
AND LIMIT SW NO. 1
MOON ROOF CONTROL
RE LAY
MOON ROOF
MOTOR
NO. 2 T8
,
T9
M2
D10
D11
M4 BA
A
8A 2A 20 B8
A
16 A 13 A12
W±B
W±B W±B
45
1326
BUZZER
1 2
21
3
GND MTR+ MTR± IS1 IS2
L
W
Y A
M4
B
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197
1D
10 1J 11F61F 5
1I
7
BZ1
3
BZ1
8BZ1 7BZ12BZ1 6
4
W±B
W±B W±B W±B
Y±R Y±R
L±Y L±B L±R
L±W
V
P
V±W
P±L
W±B
W±B
W±B
L
R
1273 POWER MAIN
RELAY
MOON RO OF CO NTROL
RELAY
OPEN
CLOSE
DOWN
UP
MOON ROOF
CONTROL SW 30A
POWER
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
M3
M2
5231
Q
R
S TIMER S R
Q
TIMER
6
2
3
15 1
2
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198
MOON ROOF
CURRENT IS APPLIED AT ALL TIMES THROUGH POWER FUSE TO TERMINAL 5 OF POWER MAIN RELAY AND ALSO THROUGH DOME
FUSE TO TERMINAL 12 OF MOON ROOF CONTROL RELAY. WITH THE IGNITION SW TURNED ON, THE CURRENT FLOWS TERMINAL 1
OF POWER MAIN RELAY " TERMINAL 2 " TO GROUND THROUGH ECU±IG FUSE. AS A RESULT, POWER MAIN RELAY IS ACTIVATED
AND THE CURRENT TO TERMINAL 5 OF POWER MAIN RELAY FLOWS FROM TERMINAL 3 OF RELAY TO TERMINAL 6 OF MOON ROOF
CONTROL RELAY.
1. SLIDE OPEN OPERATION
WHEN THE IGNITION SW IS TURNED ON AND THE MOON ROOF CONTROL SW IS PUSHED TO THE OPEN POSITION, A SIGNAL IS
INPUT FROM TERMINAL 5 OF MOON ROOF CONTROL SW TO TERMINAL 1 OF MOON ROOF CONTROL RELAY. MOON ROOF LIMIT SW
NO. 2 IS ON AT THIS TIME.
WHEN THIS OCCURS, THE RELAY IS ACTIVATED AND THE CURRENT TO TERMINAL 6 OF MOON ROOF CONTROL RELAY FLOWS
FROM TERMINAL 5 " TERMINAL 3 OF MOON ROOF MOTOR " TERMINAL 1 " TERMINAL 4 OF MOON ROOF CONTROL RELAY "
TERMINAL 11 " TO GROUND AND ROTATES THE MOTOR TO OPEN THE MOON ROOF WHILE THE SW IS BEING PUSHED TO OPEN
POSITION.
2. SLIDE CLOSE OPERATION
WITH THE IGNITION SW TURNED ON, THE MOON ROOF COMPLETELY OPEN AND MOON ROOF LIMIT SW NO. 1 AND NO. 2 BOTH ON,
WHEN THE MOON ROOF CONTROL SW IS PUSHED TO THE CLOSE POSITION A SIGNAL IS INPUT FROM TERMINAL 2 OF MOON
ROOF CONTROL SW TO TERMINAL 2 OF MOON ROOF CONTROL RELAY.
WHEN THIS OCCURS, THE RELAY IS ACTIVATED AND THE CURRENT TO TERMINAL 6 OF MOON ROOF CONTROL RELAY FLOWS
FROM TERMINAL 4 " TERMINAL 1 OF MOON ROOF MOTOR " TERMINAL 3 " TERMINAL 5 OF MOON ROOF CONTROL RELAY "
TERMINAL 11 " TO GROUND AND ROTATES THE MOTOR TO CLOSE THE MOON ROOF WHITE THE SW IS BEING PUSHED TO CLOSE
POSITION.
MOON ROOF LIMIT SW NO. 1 TURNS OFF (LIMIT SW NO. 2 IS ON) AND AT 200MM (7.9 IN) BEFORE FULLY CLOSED POSITION, SIGNAL
IS INPUT FROM TERMINAL 2 OF LIMIT SW NO. 1 TO TERMINAL 8 OF MOON ROOF CONTROL RELAY. THIS SIGNAL ACTIVATES THE
RELAY AND STOPS CONTINUITY FROM TERMINAL 6 OF MOON ROOF CONTROL RELAY TO TERMINAL 11. AS A RESULT, THE MOON
ROOF STOPS AT THIS POSITION.
TO CLOSE THE MOON ROOF COMPLETELY, PUSHING THE MOON ROOF CONTROL SW AGAIN TO THE CLOSE SIDE CAUSES A
SIGNAL TO BE INPUT AGAIN TO TERMINAL 2 OF MOON ROOF CONTROL RELAY. THIS ACTIVATES THE RELAY AND THE MOON ROOF
WILL CLOSE AS LONG AS THE MOON ROOF CONTROL SW IS BEING PUSHED, ALLOWING\
THE MOON ROOF TO FULLY CLOSE.
3. TILT UP OPERATION
WHEN THE MOON ROOF CONTROL SW IS PUSHED TO TILT UP POSITION, WITH THE IGNITION SW TURNED ON AND THE MOON
ROOF COMPLETELY CLOSED (MOON ROOF LIGHT SW NO.2 IS OFF), A SIGNAL IS INPUT FROM TERMINAL 1 OF MOON ROOF
CONTROL SW TO TERMINAL 3 OF MOON ROOF CONTROL RELAY. AS A RESULT, THE RELAY IS ACTIVATED AND THE CURRENT TO
TERMINAL 6 OF RELAY FLOWS FROM TERMINAL 4 OF THE RELAY " TERMINAL 1 OF MOON ROOF MOTOR " TERMINAL 3 "
TERMINAL 5 OF RELAY " TERMINAL 11 TO GROUND AND ROTATES THE MOTOR SO THAT TILT UP OPERATION OCCURS AS LONG
AS THE MOON ROOF CONTROL SW IS PUSHED ON THE TILT UP SIDE.
4. TILT DOWN OPERATION
WHEN THE MOON ROOF CONTROL SW IS PUSHED TO TILT DOWN POSITION, WITH THE IGNITION SW TURNED ON AND THE MOON
ROOF TILTED UP (NO. 1 AND NO. 2 MOON ROOF LIMIT SWITCHES ARE BOTH OFF), A SIGN\
AL IS INPUT FROM TERMINAL 3 OF MOON
ROOF CONTROL SW TO TERMINAL 7 OF MOON ROOF CONTROL RELAY.
AS A RESULT, THE RELAY IS ACTIVATED AND THE CURRENT TO TERMINAL 6 OF RELAY FLOWS FROM TERMINAL 5 OF RELAY "
TERMINAL 3 OF MOON ROOF MOTOR " TERMINAL 1 " TERMINAL 4 OF RELAY " TERMINAL 11 " TO GROUND AND ROTATES THE
MOTOR SO THAT TILT DOWN OPERATION OCCURS AS LONG AS THE MOON ROOF CONTROL SW IS PUSHED ON THE TILT DOWN
SIDE. (DURING TILT DOWN, LIMIT SW NO. 1 IS CHANGED FROM OFF TO ON.)
5. KEY OFF MOON ROOF OPERATION
WITH THE IGNITION SW TURNED FROM ON TO OFF, THE THEFT DETERRENT ECU OPERATES AND CURRENT FLOWS FROM DOOR
FUSE TO TERMINAL (A)8 OF THE ECU OR DOME FUSE TO TERMINAL (A)20 OF THE ECU " TERMINAL (B)8 " TERMINAL 1 OF
POWER MAIN RELAY " TERMINAL 2 " TO GROUND FOR ABOUT 60 SECONDS. THE SAME AS NORMAL OPERATION, THE CURRENT
FLOWS FROM POWER FUSE " TERMINAL 5 OF THE POWER MAIN RELAY " TERMINAL 3 " TERMINAL 6 OF THE MOON ROOF
CONTROL RELAY. AS A RESULT, FOR ABOUT 60 SECONDS AFTER THE IGNITION SW IS TURNED OFF, THE FUNCTIONING OF THIS
RELAY MAKES IT POSSIBLE TO OPEN AND CLOSE THE MOON ROOF. ALSO, BY OPENING THE FRONT DOOR (DOOR DETECT SW
ON) WITHIN ABOUT 60 SECONDS AFTER TURNING THE IGNITION SW TO OFF, A SIGNAL IS INPUT TO TERMINALS (A)12 OR (A)13 OF
THEFT DETERRENT ECU. AS A RESULT, THE ECU TURNS OFF AND OPEN AND CLOSE MOVEMENT OF THE MOON ROOF STOPS.
SYSTEM OUTLINE
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