ignition LEXUS SC300 1991 Service Repair Manual

105
TURN SIGNAL FLASHER
(4) 3 ± GROUND: CHANGES FROM APPROX. 12 VOLTS TO 0 VOLTS WITH IGNITION SW ON AND TURN SIGNAL SW LEFT, OR WITH
HAZARD SW ON
(4) 5 ± GROUND: CHANGES FROM APPROX. 12 VOLTS TO 0 VOLTS WITH IGNITION SW ON AND TURN SIGNAL SW RIGHT, OR WITH
HAZARD SW ON
(4) 4 ± GROUND: CONTINUITY WITH TURN SIGNAL SW LEFT, OR HAZARD SW ON
(4) 2 ± GROUND: CONTINUITY WITH TURN SIGNAL SW RIGHT, OR HAZARD SW ON
(4) 1 ± GROUND: APPROX. 12 VOLTS WITH IGNITION SW ON OR HAZARD SW ON
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C13A28F 726R1031
C14B28F 826R1131
C1628H 729
: 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)
1A20ENGINE ROOM MAIN WIRE
1C20FLOOR WIRE
1E20INSTRUMENT PANEL WIRE
1H
1J20COWL WIRE
1K
20COWL WIRE
3A
3D22INSTRUMENT PANEL WIRE
3G
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IE136ENGINE ROOM MAIN WIRE AND COWL WIRE (R/B NO. 4)
IG136INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO 5)IG236INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)
IQ138INSTRUMENT PANEL WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PANEL CENTER)IQ238INSTRUMENT PANEL WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PA N E L CENTER)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EA34FRONT SIDE OF RIGHT FENDER
EB34FRONT SIDE OF LEFT FENDER
IF36LEFT KICK PANEL
BM40BACK PANEL CENTER
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I 738COWL WIREB1540FLOOR MAIN WIRE
SERVICE HINTS
WhereEverybodyKnowsYourName

184
UNLOCK AND SEAT BELT WARNING
1E
12
3A
4
3D
13
1B
5 2
B
1
A
7
1E 1
1H
13
1D
10
1J
1 1C
12 1D 8
1I
15
9
10
6 3
2
1
BK
IF 10A
DOME
10A
GAUGE
SEAT BELT
WARNING LIGHT
[COMB. METER]
INTEGATION RELAY
BUZZER TI M ER
UNLOCK
WARNING SW
[IGNITION SW] BUCKLE
SW LH
DOOR OPEN
DETECTION
SW LH
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
FROM POWER SOURCE SYSTEM(
SEE PAGE 56 )
C12 ,C 14
D10
B4
I15
R
R
Y
Y
W±B
W±B
W±B
Y
W±B
W±B
W±B W±B B±L B±L
R±W
W±B
W±B
V
86
5
10 179
AB
1 2
(W/ MEMORY )
( W/O MEMORY )
( W/ MEMORY )
( W/O MEMORY )
Ba1
14
Ba2
5 Ba2
6 Ba1
11
WhereEverybodyKnowsYourName

185
CURRENT ALWAYS FLOWS TO TERMINAL 1 OF THE INTEGRATION RELAY THROUGH DOME FUSE.
1. SEAT BELT WARNING SYSTEM
WHEN THE IGNITION SW IS TURNED ON, CURRENT FLOWS FROM THE GAUGE FUSE TO TERMINAL 7 OF THE INTEGRATION RELAY.
AT THE SAME TIME, CURRENT FLOWS TO TERMINAL 9 OF THE RELAY FROM THE GAUGE FUSE THROUGH THE SEAT BELT
WARNING LIGHT. THIS CURRENT ACTIVATES THE INTEGRATION RELAY AND, FOR APPROX. 4±8 SECONDS, CURRENT FLOWING
THROUGH THE WARNING LIGHT FLOWS FROM TERMINAL 9 OF THE RELAY " TERMINAL 10 " GROUND, CAUSING THE WARNING
LIGHT TO LIGHT UP. AT THE SAME TIME AS THE WARNING LIGHT LIGHTS UP, A BUCKLE SW OFF SIGNAL IS INPUT TO TERMINAL 8
OF THE RELAY, THE CURRENT FLOWING TO TERMINAL 7 OF THE RELAY FLOWS FROM TERMINAL 10 " GROUND AND THE SEAT
BELT WARNING BUZZER SOUNDS FOR APPROX. 4±8 SECONDS. HOWEVER, IF THE SEAT BELT IS PUT ON DURING THIS PERIOD
(WHILE THE BUZZER IS SOUNDING), SIGNAL INPUT TO TERMINAL 8 OF RELAY STOPS AND THE CURRENT FLOW FROM TERMINAL 7
OF THE RELAY " TERMINAL 10 " GROUND IS CUT, CAUSING THE BUZZER TO STOP.
2. UNLOCK WARNING SYSTEM
WITH THE IGNITION KEY INSERTED IN THE KEY CYLINDER (UNLOCK SW ON), THE IGNITION SW STILL OFF AND \
DOOR OPEN (DOOR
COURTESY SW ON), WHEN A SIGNAL IS INPUT TO TERMINAL 6 OF THE RELAY, THE INTEGRATION RELAY OPERATES, CURRENT
FLOWS FROM TERMINAL 7 OF THE RELAY " TERMINAL 10 " GROUND AND UNLOCK WARNING BUZZER SOUNDS.
B 4 BUCKLE SW LH
1±2 : CLOSED WITH DRIVER'S LAP BELT IN USE
D10 DOOR COURTESY SW LH
3±6 : CLOSED WITH LH DOOR OPEN
I15 UNLOCK WARNING SW [IGNITION SW]
10±9: CLOSED WITH IGNITION KEY IN CYLINDER
INTEGRATION RELAY
10±GROUND: ALWAYS CONTINUITY6±GROUND: CONTINUITY WITH DRIVER'S DOOR OPEN
5±GROUND: CONTINUITY WITH IGNITION KEY IN CYLINDER
8±GROUND: CONTINUITY WITH DRIVER'S LAP BELT IN USA
9±GROUND: 0 VOLTS FOR 4±8 SECONDS WITH IGNITION SW ON AND APPROX. 12 VOLTS 4±8 SECONDS AFTER IGNITION SW ON
1±GROUND: ALWAYS APPROX. 12 VOLTS
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
B 432C14B28I1529
C12A28D1030
: 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
1C20FLOOR MAIN
1D20FRONT DOOR LH WIRE
1E20INSTRUMENT PANEL WIRE
1H
1I20COWL WIRE
1J
20COWL WIRE
3A22INSTRUMENT PANEL WIRE3D22INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
Ba142FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)Ba242FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
BK40UNDER THE CENTER PILLAR LH
SYSTEM OUTLINE
SERVICE HINTS
WhereEverybodyKnowsYourName