1991 LEXUS SC400 warning light

87
EABM
E4 B15 B15
B14
B14
1 2 1
2 1C
21E 12
3D
13 3A
4
B
11 A
1
G
G
W±B GG
W±B W±B
Y
Y
V±G
V±G YY
G
G G
W±B
W±B
W±B
W±B G±R G±R
W±B
W±B W±B G G
911
384
111
255
G±R
W±B FRONT CLEARANCE
LIGHT RH
LIGHT FAILURE
SENSOR
10A
GAUGE
REAR LIGHT
WARNING LIGHT
[COMB. METER]
TAI L LI GHT
[REAR COMB. LIGHT]
LICENCE PLATE
LIGHT
L3
L2
R11
R10
RH
LH FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
HOLD
CIRCUIT
BU1
9
C13 ,
C14
B A
+
±
FRONT SI DE M ARK ER
LIGHT RHF6
F4
E1
E1
B
+PK
±PK WRN
W±B
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88
TAILLIGHT
WHEN THE LIGHT CONTROL SW IS TURNED TO TAIL OR HEAD POSITION. THE CURRENT FLOWS TO TERMINAL 3 OF THE LIGHT
FAILURE SENSOR THROUGH THE TAIL FUSE.
WHEN THE IGNITION SW IS TURNED ON, THE CURRENT FLOWS FROM THE GAUGE FUSE TO TERMINAL 8 OF THE LIGHT FAILURE
SENSOR, AND ALSO FLOWS THROUGH THE REAR LIGHT WARNING LIGHT TO TERMINAL 4 OF THE LIGHT FAILURE SENSOR.
TAILLIGHT DISCONNECTION WARNING
WITH THE IGNITION SW ON AND THE LIGHT CONTROL SW TURNED TO TAIL OR HEAD POSITION. IF THE TAILLIGHT CIRCUIT IS
OPEN, THE LIGHT FAILURE SENSOR DETECTS THE FAILURE BY THE CHANGE IN CURRENT FLOWING FROM TERMINAL 3 OF THE
LIGHT FAILURE SENSOR TO TERMINAL 9, 11 AND THE WARNING CIRCUIT OF THE LIGHT FAILURE SENSOR IS ACTIVATED.
AS A RESULT, THE CURRENT FLOWS FROM TERMINAL 4 OF THE LIGHT FAILURE SENSOR " TERMINAL 11 " GROUND AND TURNS
THE REAR LIGHT WARNING LIGHT ON, WHICH REMAINS ON UNTIL THE LIGHT CONTROL SW IS TURNED O\
FF.
TAILLIGHT RELAY
5±3 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
L 3 LIGHT FAILURE SENSOR
4, 8±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
3±GROUND : APPROX. 12 VOLTS WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
11±GROUND : ALWAYS CONTINUITY
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C13B28F 526L 230
C14A28F 626L 330
C1528F 926R1031
F 326I16A29 (USA)R1131
F 426I16B29 (CANADA)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1A20ENGINE ROOM MAIN WIRE1B20ENGINE ROOM MAIN WIRE
1C20FLOOR WIRE
1E20INSTRUMENT PANEL WIRE
1J20COWL WIRE1K20COWL WIRE
3A22INSTRUMENT PANEL WIRE3D22INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
BU140FLOOR WIRE AND INSTRUMENT PANEL WIRE (LEFT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EA34FRONT SIDE OF RIGHT FENDER
IF36LEFT KICK PANEL
BM40BACK PANEL CENTER
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
E 1E1134ENGINE ROOM MAIN WIRE
E 434ENGINE ROOM MAIN WIREB1440FLOOR MAIN WIREE 534ENGINE ROOM MAIN WIREB1540FLOOR MAIN WIRE
SYSTEM OUTLINE
SERVICE HINTS
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11 5
CURRENT ALWAYS FLOWS TO TERMINAL (A)8 OF THE DOOR LOCK ECU THROUGH THE DOOR FUSE, AND TO TERMINAL (A)20
THROUGH THE DOME FUSE.
WHEN THE IGNITION SW IS TURNED ON, THE CURRENT FLOWING THROUGH THE ECU±IG FUSE " TERMINAL (A)2 OF THE ECU "
TERMINAL (B)8 FLOWS THROUGH THE COIL SIDE OF THE POWER MAIN RELAY TO GROUND, CAUSING THE RELAY TO OPERATE.
THE CURRENT FLOWING THROUGH THE POWER FUSE FLOWS TO THE DOOR LOCK CONTROL SW LH, CAUSING THE INDICATOR
LIGHT TO LIGHT UP.
1. MANUAL LOCK OPERATION
WHEN THE DOOR CONTROL SW OR KEY SW ARE PUSHED TO LOCK POSITION, A LOCK SIGNAL IS INPUT TO TERMINAL (A)17, (A)14
(FOR KEY SW) OF THE DOOR LOCK ECU AND CAUSES THE ECU TO FUNCTION. CURRENT FLOWS FROM TERMINAL (A)8 OF THE
ECU " TERMINAL (A)4 " TERMINAL 5 OF THE DOOR LOCK MOTORS " TERMINAL 2 " TERMINAL (A)3 OF THE ECU " TERMINAL
(A)16 " TO GROUND AND THE DOOR LOCK MOTOR CAUSES THE DOOR TO LOCK.
2. MANUAL UNLOCK OPERATION
WHEN THE DOOR LOCK CONTROL SW OR KEY ARE PUSHED TO UNLOCK POSITION, AN UNLOCK SIGNAL IS INPUT TO TERMINAL
(A)18, (A)10 (FOR KEY SW LH) OR (A)15 (FOR KEY SW RH) OF THE DOOR LOCK ECU AND CAUSES THE ECU TO FUNCTION.
CURRENT FLOWS FROM TERMINAL (A)8 OF THE ECU " TERMINAL (A)3 " TERMINAL 2 OF THE DOOR LOCK MOTORS " TERMINAL
5 " TERMINAL (A)4 OF THE ECU "TERMINAL (A)16 " TO GROUND AND THE DOOR LOCK MOTOR CAUSES THE DOOR TO
UNLOCK.
WHEN UNLOCK OPERATION OCCURS USING THE LH DOOR KEY SW, PERFORMING THE UNLOCK OPERATION ONCE UNLOCKS
ONLY THE DRIVER'S DOOR. TO UNLOCK ALL THE OTHER DOORS TOGETHER, UNLOCK OPERATION MUST BE PERFORMED AGAIN
WITHIN 3 SECONDS OF THE FIRST OPERATION.
3. IGNITION KEY REMINDER OPERATION
* OPERATION OF DOOR LOCK BUTTON (OPERATION OF DOOR LOCK MOTORS)
WHEN THE IGNITION KEY IS IN THE CYLINDER (UNLOCK WARNING SW ON) AND THE DOOR IS OPENED AND LOCKED USING
DOOR LOCK BUTTON (DOOR LOCK MOTOR), THE DOOR IS LOCKED ONCE BUT EACH DOOR IS UNLOCKED SOON BY THE
OPERATION OF THE ECU. AS A RESULT OF ECU ACTIVATION, THE CURRENT FLOWS FROM TERMINAL (A)8 OF THE ECU "
TERMINAL (A)3 " TERMINAL 2 OF THE DOOR LOCK MOTORS " TERMINAL 5 " TERMINAL (A)4 OF THE ECU " TERMINAL (A)16
" TO GROUND AND CAUSES ALL THE DOORS TO UNLOCK.
THE SAME APPLIES TO OPERATION OF THE DOOR LOCK CONTROL SW AND DOOR LOCK KEY SW.
* KEY LESS LOCK OPERATION
WHEN THE IGNITION KEY IS STILL INSERTED IN THE CYLINDER (UNLOCK WARNING SW ON), THE DOOR IS OPEN AND UNLOCK
OPERATION IS PREVENTED BY KEEPING THE DOOR LOCK BUTTON PRESSED TO THE LOCK SIDE, THE DOOR IS KEPT IN THE
LOCK CONDITION. IF THE DOOR IS THEN CLOSED, A SIGNAL IS INPUT TO THE ECU FROM THE DOOR COURTESY SW. THIS
ACTIVATES THE ECU AND EACH DOOR IS UNLOCKED.
SYSTEM OUTLINE
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11 6
THEFT DETERRENT AND DOOR LOCK CONTROL
D 7, D 8 DOOR KEY LOCK AND UNLOCK SW LH, RH
1±2 : CLOSED WITH DOOR LOCK CYLINDER UNLOCKED WITH KEY
3±2 : CLOSED WITH DOOR LOCK CYLINDER LOCKED WITH KEY
D10, D11 DOOR LOCK MOTOR, DOOR UNLOCK DETECTION SW AND DOOR OPEN DETECTION SW LH, RH
1±4: CLOSED WITH UNLOCK POSITION
E 5 ENGINE HOOD COURTESY SW
1±2: CLOSED WITH ENGINE HOOD OPEN
I15 UNLOCK WARNING SW [IGNITION SW]
9±10: CLOSED WITH IGNITION KEY IN CYLINDER
L 5 LUGGAGE COMPARTMENT KEY UNLOCK SW
1±3: CLOSED WITH DOOR LOCK CYLINDER UNLOCK WITH KEY
L 6 LUGGAGE COMPARTMENT LIGHT SW
1±GROUND: CLOSED WITH DOOR OPEN
T 8(B) THEFT DETERRENT AND DOOR LOCK ECU
1±GROUND: CONTINUITY WITH LUGGAGE COMPARTMENT DOOR TO UNLOCK POSITION
12±GROUND: CONTINUITY WITH ENGINE HOOD OPEN
10±GROUND: CONTINUITY WITH LUGGAGE COMPARTMENT DOOR OPEN
7±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ACC OR ON POSITION
T 9(A) THEFT DETERRENT AND DOOR LOCK ECU
1±GROUND: APPROX. 12 VOLTS WITH SHIFT LEVER IN N OR P POSITION AND IGNITION SW AT ST POSITION
2±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
6±GROUND: CONTINUITY WITH IGNITION KEY IN CYLINDER
7±GROUND: CONTINUITY WITH FRONT RH DOOR TO UNLOCK POSITION
8±GROUND: ALWAYS APPROX. 12 VOLTS
10±GROUND: CONTINUITY WITH DOOR LOCK KEY SW LH TO UNLOCK POSITION
11±GROUND: CONTINUITY WITH FRONT LH DOOR TO UNLOCK POSITION
12±GROUND: CONTINUITY WITH FRONT RH DOOR OPENED
13±GROUND: CONTINUITY WITH FRONT LH DOOR OPENED
14±GROUND: CONTINUITY WITH DOOR LOCK KEY SW RH TO LOCK POSITION
15±GROUND: CONTINUITY WITH DOOR LOCK KEY SW RH TO UNLOCK POSITION
20±GROUND: ALWAYS APPROX. 12 VOLTS
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C1428F 926N 127
C2328F1028P 531
D 730F1430T 127
D 830I1529T 8B29
D 930L 129T 9A29
D1030L 430T1529
D1130L 530
E 526L 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
1H
1I20COWL WIRE1J20COWL WIRE
1K
3A22INSTRUMENT PANEL WIRE3F22INSTRUMENT PANEL WIRE
SERVICE HINTS
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104
TURN SIGNAL AND HAZARD WARNING LIGHT
1E
7 2
1A
71A 41C 41C 31E19 1E14
2 3 2 3 1H
11 1H 7
1J 1 3G
3
3A 1
1E 18
1K 6 3D
10
4
4
4
4
4
IQ2
8
IQ1
10 IQ1
12 IQ1 11
IG2
9IG1 10 IG123
IQ2
13
I7 I7
B15
EB EA BM IF 55
9
756 4123 10 8
66
1
4
2
5
3
A
16 A 17
B
23
IG2
8
IQ2 3
IE19
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
HAZARD TURNRH
LH
OFF
ON 20A
TURN
25A
HAZ±HORN
TURN SIGNAL
FLASHER TURN SIGNAL SW [COMB. SW]
HA ZARD SW
FRONT TURN
SIGNAL LIGHT
REAR TURN SIGNAL LIGHT
[REAR COMB. LIGHT] TURN SIGNAL INDICATOR
LIGHT [COMB. METER]
LH RH RH
LH WW
R±W R±B
R±W
R±W W±R
R±B
G± Y
G± B
W±BW±B
W±B
W±B
G±R
G±R
W
W
W±R
W±B
W±R
R±WR±B
R±B
R±W
R±W
R±B
R±W
W±BR±B
G±Y
G±B
G±Y
G±B
G±Y
G±Y G±B
W±B W±B
W±B W±B W±B W±B
W±B 5
R±B
H7
C16
F7 F8 R10 R11
C13 , C 1 4AB
LH RH
6
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106
TURN SIGNAL AND HAZARD WARNING LIGHT
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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
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