1991 LEXUS SC400 brake

151
7. AUTO CANCEL FUNCTION
A) IF ANY OF THE FOLLOWING OPERATING CONDITIONS OCCURS DURING CRUISE CONTROL OPERATION, THE SET SPEED IS
ERASED, CURRENT FLOW TO MAGNETIC CLUTCH IS STOPPED AND THE CRUISE CONTROL IS RELEASED. (MAIN SWITCH TURNS
OFF).
WHEN THIS OCCURS, THE IGNITION SWITCH MUST BE TURNED OFF ONCE BEFORE THE MAI\
N SWITCH WILL TURN ON.* OVER CURRENT TO TRANSISTER DRIVING MOTOR AND/OR MAGNETIC CLUTCH.
* WHEN CURRENT CONTINUED TO FLOW TO THE MOTOR INSIDE THE ACTUATOR IN THE THROTTLE VALVE ªOPENº DIRECTION.
* OPEN CIRCUIT IN MAGNETIC CLUTCH.
* MOMENTARY INTERRUPTION OF VEHICLE SPEED SIGNAL.
* SHORT CIRCUIT IN CRUISE CONTROL SWITCH.
* MOTOR DOES NOT OPERATE DESPITE THE MOTOR DRIVE SIGNAL BEING OUTPUT.
B) IF ANY OF THE FOLLOWING CONDITIONS OCCURS DURING CRUISE CONTROL OPERATION, THE SET SPEED IS ERASED AND
THE CRUISE CONTROL IS RELEASED. (THE POWER OF MAGNETIC CLUTCH IS CUT OFF U\
NTIL THE SET SWITCH IS ªONº AGAIN.) * WHEN THE VEHICLE SPEED FALLS BELOW THE MINIMUM SPEED LIMIT, APPROX. 40 KM/H ( 2.5 MPH)
* WHEN THE VEHICLE SPEED FALLS MORE THAN 16 KM/H ( 10 MPH) BELOW THE SET SPEED, E.G. ON AN UPWARD SLOPE.
* WHEN POWER TO THE CRUISE CONTROL SYSTEM IS MOMENTARILY CUT OFF.
C) IF ANY OF THE FOLLOWING CONDITIONS OCCURS DURING CRUISE CONTROL OPERATION, THE CRUISE CONTROL IS
RELEASED.
* OPEN CIRCUIT FOR TERMINAL 1 OF CRUISE CONTROL ECU AND SPLICE POINT ªI 9º.
8. AUTOMATIC TRANSMISSION CONTROL FUNCTION
*IN OVERDRIVE. IF THE VEHICLE SPEED BECOMES LOWER THAN THE OVERDRIVE CUT SPEED (SET SPEED MINUS APPROX. 4
KM/H, 2.5 MPH) DURING CRUISE CONTROL OPERATION, SUCH AS DRIVING UP A HILL, THE OVERDRIVE IS RELEASED AND THE
POWER INCREASED TO PREVENT A REDUCTION IN VEHICLE SPEED.
* AFTER RELEASING THE OVERDRIVE, VEHICLE SPEED BECOMES HIGHER THAN THE OVE\
RDRIVE RETURN SPEED (SET SPEED
MINUS APPROX. 2 M/H, 1.2 MPH) AND THE ECU JUDGES BY THE SIGNALS FROM POTENTIOMETER OF THE ACTUATOR THAT THE
UPWARD SLOPE HAS FINISHED, OVERDRIVE IS RESUMED AFTER APPROXIMATELY 6 SECONDS.
* DURING CRUISE CONTROL DRIVING, THE CRUISE CONTROL OPERATION SIGNAL IS OUTPUT FROM THE CRUISE CONTROL
ECU TO THE ENGINE AND TRANSMISSION ECU. UPON RECEIVING THIS SIGNAL, THE ENGIN\
E AND TRANSMISSION ECU
CHANGES THE SHIFT PATTERN TO NORMAL.
TO MAINTAIN SMOOTH CRUISE CONTROL OPERATION (ON A DOWNWARD SLOPE ETC.), LOCK±UP RELEASE OF THE
TRANSMISSION WHEN THE IDLING POINT OF THE THROTTLE POSITION IS ªONº IS FORBIDD\
EN.
C 8 CRUISE CONTROL ACTUATOR
1±3 : APPROX. 2K

5±4 : APPROX. 38.5

C15 CRUISE CONTROL SW [COMB. SW]
15±6 :CONTINUITY WITH MAIN SW ON
5±6 :APPROX. 420
WITH CANCEL SW ON
APPROX. 70
WITH RESUME/ACCEL SW ON
APPROX. 200
WITH SET/COAST SW ON
C19 CRUISE CONTROL ECU
14±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
1, 15±GROUND : ALWAYS APPROX. 12 VOLTS
3±GROUND : CONTINUITY WITH PARKING BRAKE LEVER PULLED UP (ONE OF THE CANCEL SW) OR BRAKE LEVER WARNING SW ON
20±GROUND : 1 PULSE WITH 40CM (DRIVER VEHICLE SLOWLY)
18±GROUND : APPROX. 420
WITH CANCEL SW ON IN CONTROL SW
APPROX. 200
WITH SET/COAST SW ON IN CONTROL SW
APPROX. 70
WITH RESUME/ACCEL SW ON IN CONTROL SW
13±GROUND : ALWAYS CONTINUITY
SERVICE HINTS
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130
ECT AND A/T INDICATOR
THIS SYSTEM, ELECTRICALLY CONTROLS THE LINE PRESSURE, THROTTLE PRESSURE, LOCK±UP PRESSURE AND\
ACCUMULATOR
PRESSURE ETC. THROUGH THE SOLENOID VALVE. THE ECT IS A SYSTEM WHICH PRECISELY CONTROLS GEAR SHIFT TIMING AND
LOCK±UP TIMING IN RESPONSE TO THE VEHICLE'S DRIVING CONDITIONS AND THE ENGINE OPERATING CONDITIONS DETECTED
BY VARIOUS SENSORS, MAKING SMOOTH DRIVING POSSIBLE BY SHIFT SELECTION FOR EA\
CH GEAR WHICH IS THE MOST
APPROPRIATE TO THE DRIVING CONDITIONS AT THAT TIME, AND CONTROLS THE ENGINE TORQUE DURING SHIFTING TO ACHIEVE
OPTIMUM SHIFT FEELING.
1. GEAR SHIFT OPERATION
WHEN DRIVING, THE ENGINE WARM UP CONDITION IS INPUT AS A SIGNAL TO TERMINAL (B)44 OF THE ECU FROM THE EFI WATER
TEMP. SENSOR AND THE VEHICLE SPEED SIGNAL FROM SPEED SENSOR NO.2 IS INPUT TO TERMINAL (B)23 OF THE ECU. AT THE
SAME TIME, THE THROTTLE VALVE OPENING SIGNAL FROM THE THROTTLE POSITION SENSOR (MAIN) IS INPUT TO TERMINAL
(B)43 OF THE ECU AS ENGINE RPM CONDITION (IDLING, HIGH LOAD AND ACCELERATION CONDITIONS) SIGNAL.
BASED ON THESE SIGNALS, THE ECU SELECTS THE BEST SHIFT POSITION FOR DRIVING C\
ONDITIONS AND SENDS CURRENT TO
THE ECT SOLENOIDS.
WHEN SHIFTING TO 1ST SPEED, THE CURRENT FLOWS FROM TERMINAL (B)10 OF THE ECU " TERMINAL 1 OF ECT SOLENOIDS "
GROUND AND CONTINUITY TO NO.1 SOLENOID CAUSES THE SHIFT (NO.2 SOLENOID DOES NOT HAVE CONTINUITY AT THIS TIME).
FOR 2ND SPEED, THE CURRENT FLOWS SIMULTANEOUSLY FROM TERMINAL (B)9 OF THE ECU " TERMINAL 2 OF ECT SOLENOIDS
" GROUND, AND FROM TERMINAL (B)10 OF THE ECU " TERMINAL 1 OF ECT SOLENOIDS " GROUND, AND CONTINUITY TO NO.1
AND NO.2 SOLENOIDS CAUSES THE SHIFT.
FOR 3RD SPEED, THERE IS NO CONTINUITY TO NO.1 SOLENOID, ONLY TO NO.2 SOLENOID, CAUSING THE SHIFT.
SHIFTING INTO THE 4TH SPEED (OVERDRIVE) OCCURS WHEN NO CURRENT FLOWS TO NO.1 AND NO.2 SOLENOIDS. THE NO.4
SOLENOID (FOR ACCUMULATOR BACK PRESSURE MODULATION) IS INSTALLED TO ADJUST THE BACK PRESSURE ON THE
ACCUMULATOR AND CONTROL THE HYDRAULIC PRESSURE DURING SHIFTING AND LOCK±UP IN \
ORDER TO PROVIDE SMOOTH
SHIFTING WITH LITTLE SHIFT SHOCK.
2. LOCK±UP OPERATION
WHEN THE ECT ECU DECIDES, BASED ON EACH SIGNAL, THAT THE LOCK±UP CONDITION HAS BEEN MET, THE CURRENT FLOWS
FROM " TERMINAL (B)8 OF THE ECU " TERMINAL 3 OF THE ECT SOLENOID " GROUND, CAUSING CONTINUITY TO THE LOCK±UP
SOLENOID AND CAUSING LOCK±UP OPERATION.
3. STOP LIGHT SW CIRCUIT
IF THE BRAKE PEDAL IS DEPRESSED (STOP LIGHT SW ON) WHEN DRIVING IN LOCK±UP CONDITION, A SIGNAL IS INPUT\
TO
TERMINAL (A)4 OF THE ECU. THE ECU OPERATES AND CUTS THE CURRENT TO THE SOLENOID TO RELEASE LOCK±UP.
4. OVERDRIVE CIRCUIT
*O/D MAIN SW ON
WHEN THE O/D MAIN SW IS TURNED ON (SW POINT IS OPEN), A SIGNAL IS INPU\
T TO TERMINAL (A)28 OF THE ECU AND THE ECT
CAUSES SHIFT TO OVERDRIVE WHEN THE CONDITIONS FOR OVERDRIVE ARE MET.
* O/D MAIN SW OFF
WHEN THE O/D MAIN SW IS TURNED OFF (SW POINT IS CLOSED), THE CURRENT FLOWI\
NG THROUGH THE O/D OFF INDICATOR
LIGHT FLOWS TO GROUND BY WAY OF THE O/D MAIN SW AND CAUSES THE O/D OFF INDICATOR LIGHT TO LIGHT UP. AT THE
SAME TIME, A SIGNAL IS INPUT TO TERMINAL (A)28 OF THE ECU AND THE ECT PREVENTS SHIFT INTO OVERDRIVE.
5. ECT PATTERN SELECT SW CIRCUIT
WHEN THE ECT PATTERN SELECT SW IS CHANGED FROM ªNORMALº TO ªPOWERº, THE CURRENT THROUGH THE GAUGE FUSE
FLOWS TO TERMINAL 4 OF ECT PATTERN SELECT SW " TERMINAL 3 " TERMINAL (B)4 OF A/T INDICATOR " TERMINAL (C)23 "
GROUND AND CAUSES THE INDICATOR LIGHT TO LIGHT UP. AT THE SAME TIME, THE CURRENT FLOWS TO TERMINAL (A)18 OF
THE ECU AND THE ECU PERFORMS SHIFT UP AND SHIFT DOWN AT A HIGHER VEHICLE SPEED RANGE COMPARED WITH
ªNORMALº POSITION.
6. KICK DOWN OPERATION
WHEN THE ACCELERATOR IS DEPRESSED FURTHER THAN THE FULL THROTTLE POSITION WHILE DRIVING, THE KICK DOWN SW
TURNS ON AND ITS SIGNAL IS INPUT TO TERMINAL (A)3 OF THE ECU. THEN, THE ECU CONTROLS THE CURRENT WHICH FLOWS
FROM TERMINALS (B)10 AND (B)9 OF THE ECU TO THE NO. 1 AND NO. 2 SOLENOIDS AND SHIFTS DOWN BY TURNING THE
SOLENOIDS ON AND OFF.
7. CRUISE CONTROL
WHEN CRUISE CONTROL OPERATION IS SELECTED A SIGNAL IS INPUT TO TERMINAL (A)12 OF THE ECU FROM CRUISE CONTROL
ECU. AS A RESULT, THE ECU OPERATES AND CONTROLS OVERDRIVE, LOCK±UP AND SO ON FOR SMOOTH DRIVING.
SYSTEM OUTLINE
WhereEverybodyKnowsYourName

131
E 1 ECT SOLENOID
1±4 : APPROX. 5.3

2±5 : APPROX. 3.7

3±GROUND : APPROX. 13.2

6±GROUND : APPROX. 13.2

E 2 EFI WATER TEMP. SENSOR
1±2 : APPROX. 16.2K
( ±20 °C ±4 °F)
APPROX. 2.5K
( 20 °C 68 °F)
APPROX. 0.32K
( 80 °C 176 °F)
E 8 ECT PATTERN SELECT SW
4±3 : CLOSED WITH ECT PATTERN SELECT SW AT POWER POSITION
E 9(A), E10(B) ENGINE AND ECT ECU
BATT ± E1: ALWAYS APPROX. 12 VOLTS
IGSW ± E1: APPROX. 12 VOLTS WITH IGNITION SW ON
BK ± E1: APPROX. 12 VOLTS WITH BRAKE PEDAL DEPRESSED
P ± E1: APPROX. 12 VOLTS WITH IGNITION SW ON POSITION AND ECT PATTERN SELECT SW AT POWER POSITION
KD±GROUND :CONTINUITY WITH KICK DOWN SW ON
OD2 ± E1: APPROX. 12 VOLTS WITH O/D MAIN SW ON
0 VOLTS WITH O/D MAIN SW ON
+B±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
+B1±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
MREL±GROUND:APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
E01±GROUND : ALWAYS CONTINUITY
E02±GROUND : ALWAYS CONTINUITY
L±GROUND : APPROX. 12 VOLTS WITH SHIFT LEVER AT ªLº RANGE
2±GROUND : APPROX. 12 VOLTS WITH SHIFT LEVER AT ª2º RANGE
R±GROUND : APPROX. 12 VOLTS WITH SHIFT LEVER AT ªRº RANGE
E1±GROUND : ALWAYS CONTINUITY
VC±VTA1 : LESS THAN 1 VOLTS WITH THROTTLE VALVE FULLY CLOSED
MORE THAN 3 VOLTS WITH THROTTLE VALVE OPEN
VTA1 ± E2: CONTINUITY WITH THROTTLE VALVE FULLY CLOSED APPROX. 4K
WITH THROTTLE VALVE FULLY OPEN
VC ± E2: APPROX. 5 VOLTS
O 1 O/D DIRECT CLUTCH SPEED SENSOR
1±2 : APPROX. 620

S 4 SPEED SENSOR NO.2 (FOR ECT)
1±2 : APPROX. 620

S12 STOP LIGHT SW
2±1 : CLOSED WITH BRAKE PEDAL DEPRESSED
SERVICE HINTS
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236
GROUND POINT
FRONT TURN SIGNAL
LIGHT LH
ENGINE HOOD
COURTESY SW
TRACTION PUMP AND
MOTOR
HEATER RELAY
ABS ACTUATOR RELAY
TELEPHONE
TRANSCEIVER
AND SPEAKER RELAY
ENGINE OIL LEVEL
WARNING SW
COMBINATION METER
(E1 )
EFI ECU
TRACTION ECU
CHECK CONNECTOR
(
E1 ) CORNERING LIGHT LH
FRONT SIDE MAKER
LIGHT LH
BRAKE FLUID LEVEL
SW
FRONT CLEARANCE
LIGHT LH
FRONT SIDE MAKER
LIGHT RH
FRONT CLEARANCE
LIGHT RH
ABS ACTUATOR
FRONT TURN SIGNAL
LIGHT RH
CRUISE CONTROL
ACTUATOR
OXYGEN SENSOR SUB
(
FOR USA SPEC. )
TDCL (
E1 )
WASHER LEVEL SW EFI MAIN RELAY
CORNERING LIGHT RH
A/C PRESSURE SW
(HI GH PRESSURE )
AIR FLOW METER POWER STERRI NG
PRESSURE SW
NOISE FI LTER
(
FOR IGNI TION SYSTEM ) E4
E10
E12 2
2
BS1 4 E4
E7
E1 E5
EB EA I23
I33
E1 6
I32
E20
E20
E20
IK2 24
ED EC IK1
1 BY1
5
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W± B W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B BR
BR
W±B BR
BR
BR
W±B BR
BR±B BR BR
BR
BR
W± B
W± B
W± B
W± B
W± B
W± B
W± B
W±B
W±B
BR
BR
BR
BR BR
BR
BR
W±B
BR BR
BR
( EO1 )
( E11 )
( E1 )
( EO2 )
I27BR
(
S1 )
( E1 )
NOISE FILTER (
FOR
IGNITION SYSTEM )W±B
W/ TRACTION SYSTEM
NOI SE FILTER
(
FOR DEFOGGER SYSTEM )
W±B
W±B
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OVERALL ELECTRICAL WIRING DIAGRAM
1234
8 LEXUS SC300 (
Cont . ne xt pa ge )
4 ACC
IG1
ST1
AM1 2
1J
7 66 66 66 66
21J
5
1B
4 6666
66 66 66 2 1I
8
4 3 5 4
2
4 3
2
1 4
3
2
1 6
4
3
1
71124 1F 2F 3F
AABA A A B
C
B
A
B
A
A
A
A
A
A
BAABAABBB A A A A A B GGGF F
F
M
15 2 12 1 25 21 24 10 1 9
1 1326128 7 222 13 5 18 16 17 4 4 7IE2
1IO1
2 3
1 2
1
6
EB EA IJ M
2Bc2
12 IE2
H
4H 5H6H1H 2H3
I
2I 1J1
SFR SFL SRR SRL AST MT BSR BSM BSA
BS BM GND E2 PR VC SRC SMC SAC
MTT
BT M
EM2
BBBBBBBC
C
C
C
C
C
C
C
C
C
C
B
B
C 9IO1
EB1
6
10 IO1
3BW1 8BW1
6Bc2 5Bc2 2BW1 6BW1
7BW1
3B
1
221 1 112 2 320 741361511 7 81214 510
15 5 14 3 8 6 17
SFR SFL SRR SRL AST MT GND1 GND2 GND3 FL+ FL± FSS FR+ FR± RL+ RL± RSS RR+ RR± ALT LVL1 PKB W
B± Y
B±R
B±R R
VL
P± B
V±W R±B P
Y± B
LG
LG±B P± L
P± G
V±R
L
GR B
R± W
W±B (
SHIELDED )(
SHI ELDED)
B± R B± R
W± B L± Y G
V±Y
R± W
W± B MTT SR MR TMR E2 PR VC SRC SMC SAC TSR R± BAT I G STPTS WA TC D/G ABSO
RLORRO
FL OFRO
BRFA THFA
BRCBRP
TRCO NL PW±LR
Y
W
W
L±W B±R
R±B
L
Y R
V±Y
V±Y
V±Y
W
B±Y
R
R±W R
B±R
B±R
R
G± W
G±W B±Y
L±Y
R± B
Y
G
( SHI ELDED )
W
B
R
V± Y
V
V± W R± W R±W R±W
B±R V±Y W
W± L
V L
P±B
W± B W± B W± B
L±W Y± G
P± B P
B± Y
Y
L±W
L
W± B
W± B W± B
W
B
O±L
W± L W
O
O
W
W
O
L±GL±Y
L±G
L±Y Y±G Y±G
B
R±W
LR±W
B±Y V±R P± GP± L
LG±B LG
Y±B
P
R± B R±B V± W B±R B±R
V± Y
W±B W±B
(SHIELDED )
(
SHI EL DED )
(
SHI ELDED )I15
IGNITION SW
40A
IGSW
4 2 1456
R
T5
TRACTION PUMP
A N D MOT ORTRACTI ON BRAKE
ACTUATOR
ABS AND T RACTI ON ECU
60A MAIN
30A ABS NO. 2 60A ABS
NO. 1100A AM1
ABS
ACTUATOR
RELAY
ABS MOTOR
RELAY
TRACTION MOTOR
RELAY
TRACTION BRAKE
MAI N RELAY
10A DOME
6 BATTERY AB S A CT UA TOR
(SHI ELDED ) W± B
A7
ABS SPEED SENSOR
FRONT LH
A8
ABS SPEED SENSOR
FRONT RHA30
ABS SPEED SENSOR
REAR LH
F9
FUSE BLOCK
B±Y
From Stop Light
SW<4±6><5±6>
5BW1
A31
ABS SPEED SENSOR
REAR RH
From Alternator
º Lº < 1±2>
Power
Source ABS and Traction Control
B±R15A ECU±IGY
23 22 16 9 20 10 19
T3 ,T4
FG
(
SHI ELDED )
A4 , A5 , A6
HJ I A2 4 A , A25 B , A2 6 C
W
120A ALT
R
Fro nt s id e of
left fenderRight kick panel
Fr ont side of
right f ender
1
3
WhereEverybodyKnowsYourName

567 8
8LEXUSSC300(
Cont ' d )
22 11 4 14 8 1716 23
1B
5
3A
6 3E
3
3B
3 1E
11 3H 12
18 IK2 15 IK2 12 IJ 2 7IO1 8IO1
9IK2 5IK2 4IK2
2IK2 10IK1
23 E BRP
4E
TRCO 1D
BRC 5E
THFA 4D
BRFA 10 D
FRO 3D
FL O 12 D
RRO 5D
RLO 15 D
ABSO 8D
BAT 2E
IG1 6D
TC 16 E
TR5 11 D
IND 14 D
WT 5
K
15 K
1
K
7D P
16 D N
1EPKB
13 IK2 3H
7
From A/ T Indicat or SW
[ NEUTRAL START SW AND
BACK±UP LIGHT]< 3±7> 26 E
BCM
25 EB±
24 EB
11 E A
12 EA±
13 EACM
14 EGND
13 DCS W
3ES1
15 E
BM 2D
STP 21 E
TR2 6E
NE O 8E
VT H 19 E
VSH 10 E
IDL1 22 E
IDL2
6 2
16 IK2
13 IJ1 3H
14
1E
18 3A
2
1J
1
IJ IF EE
213645
BCM B± B A A± ACM 1J
52
3A
4
3D
13 1E
12 2 13 14
5EE1
1
L
To Engine and
ECT ECU< 2±8>
10A
GA U GE 7. 5A
TRAC
From Stop Light SW
<5±6><4±6>
From Trottle Position
Sensor< 2±8>
FromSubThrottlePosition
Sensor< 2±8>
WB±Y
L
V± R
P±G P±L
LG±B LG
Y±B P
R± B
V±W P±B L
V
R
B± R B± R
R±W L
GR
B
R±W GR
L V± W
P±B
WA TC TC ABS W TRC
B±Y
V± R
P±G P±L
LG±B LG
Y±B
P
R±B
R
B±R RR
R±B
B±Y
W
L±R Y
Y
L±R
G±W
Y± RP±L
V±Y
Y±L R
R±B
BR
Y± R
W± B
BR
G
W L
R Y B
B
W± B Y± R
W±B
W±B
W± B
BR L
GR
L
L
P±B
L±Y W
LG±R LG±R W P±B
V± W L±G
W
P±B
P±B
P±B
W±B
R± W
W
B±Y
TS WB
C3
CHECK
CONNECTOR T6
TDCL
(
Total Diagnstic
Communic ation Link )
TRACTION ECU ABS WARNI NG AND
TRACTION OFF INDICATOR
AND TRA CT I ON I NDI CA TOR
LI GHTABS
TRAC OFF
S8
SUB THROTTL E
ACTUATOR
T12
TRACTION CUT SW (
SHI ELDED )
ABS and Traction Control
To Parking Brake SW
(
Canada )
< 21±2>
To Brake Fluide Level SW
( USA )
< 21±2>
To Parking Brake SW
< 21±3>
C1 3 , C14 KL
T1 3 , T1 4 DE 7IJ2
L±R
ABS AND TRACTION ECU TRACTION ECUABS WARNING AND TRACTION OFF INDICATOR AND
TRA CT I ON I NDI CA TOR L I GHT
Right k ick panel Left k ickpanelRea r
side of
cylinder
head LH
G±W
E
E1
20
To Engine and
ECT ECU< 2± 8> BRBR
BR
1234 67891011
14 15 16 17 18 24
512
25 26
20
19 21 22 23 13 12345 7 891011
1214 15 16 17 18 22
6
19 20 21
13 12345678
16
15
14
13
12
11
10
9 12345678
16
15
14
13
12
11
10
9 1234 67891011
14 15 16 17 18 24
512
25 26
20
19 21 22 23 13
A
A2 4 B A2 5 CA26 DT13 DARK GRAY E T1 4 DARK GRAY
12 34 56 78
910 111213 141516 1718
17 18
1 2345 6789 10
23
22
21
20
19
15
14
13
12
11 16
K
C13 L C14 123
456
12
34
F
T 3 BLACK G T4 BLACK
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OVERALL ELECTRICAL WIRING DIAGRAM
1234
9 LEXUS SC300
4ACC
IG1
ST 1
AM1 2
4 32
1
66 66
3H
12
1J
7
1B
4 666
66
3H
13 10IK1 25IK2 2IK2
5IO1 7IO1 1E
12 1I 82
1J
52
3A
4
3D
13 7IE2
3 BW1 8 BW1 7 BW1 2 BW1 6 BW1 5 BW1
2 Bc2 6 Bc2 5 Bc2
EB EA I J 12 IE2
M
4 3
5 4
2
6 6EB1
8 I O1 2 I O1
5A 4A 11A 21B 17B 6B 10B 11B 22B
1D 4D 3D 2D 5D
3C 1C16B 2B 13B 3A 10A 2A 1A 7A 14B 3B
1B6A12A8A9A 19 B 20 B
15
F 1
G
RR±
RR+
RL ±
RL+
FR±
FR+
FSS
FL ±
FL+
GN D3
GND2
PKB
MT
AST
SRR LY
B± R
ABS TC TC TS WAV±W
P± B
P±B VL
Y
B±R
R
L
L V
P±B
B±R
W±B
L±WB±R B±Y
R
V±Y
V± Y
W
W±L
R±YY± LL
B±R
W
Y
B±Y
P
Y±G
L±W
L±W
L
W± B
W± B
W± B
W± B
W± B
W
B W± B V±W
P±B
VL
O±L
W± L W
O W
O
L±G L±Y
L±Y
L±G
O
W
R
R± Y
V±Y
Y±L
221 1 112 2
14 4 111622
6 23
B±Y
W
L
R
W
SFR SFL
8BRS S
W± B V± Y
WB
40A I GSW I15
IGNITION SW
ABS MOTOR
RE LA Y ABS ACTUATOR
RELAY
T6
TDCL
(
Tot al Diagnos tic
Communic ation Link )
C3
CHECK CONNE CT OR
BATTERY F9
FUSE BL OCK
ABS ACTUATOR A7
ABS SPEED
SENSOR FRONT LHA8
ABS SPEED
SENSOR FRONT RHA3 0
ABS SPEED
SE NS OR RE A R L H A31
ABS SPEED
S ENSOR RE AR RH
ABS WARNING LIGHT
[COMB. METER]
10A
GAUGE
10A
DOME
15A
ECU±I G
ABS ECU (
w/oTractionControl )
ABS(
Anti±Lock Brake System )
To Par ki ng Brak e SW
< 21±2> R±W
( SHI ELDED )
( SHI ELDED )
( SHI ELDED )
(
SHIELDED ) (
SHI ELDED )
BAT
IG1
W
TS
TC
D/G
MR
R±
SR
60A MAIN
60A ABS
NO. 1
100A AM1
120A ALT
SFR SFL SRR AST MT
BM GND 3E
3
Power
Source4
2
7
6
R
BS
A4 , A33DC
B±R
C13 , C14 FG 2
1
A22 , A23 AB
W± B
W± B
W± B
P±B
ABS ECU
(w/oTractionControl )
ABS ACTUATOR ABS WARNING LIGHT
[COMB. MRTER]
Fro nt s id e of
left fender Fr ont side of
right f enderRight k ic k panel
C
4
D
A4
E
A5 GRAY
GRAY 1
3
1IO17
STP
G±W G±W
From Stop Light SW
< 5±6> < 4±6>B
2
1
34
1
2
3
45 6
WhereEverybodyKnowsYourName

OVERALL ELECTRICAL WIRING DIAGRAM
1234
11 LEXUS SC300
4ACC
IG1
ST1
AM1 2
1J
51C 6
1I
82
1J
7
1B
51C 1
1H
10
1B
4 1K
13 2
18 BT1 6Ba1
12 BT1 BT1 13 BT1 13 I F2 IF1 IF1 I F1
7B
GN D2
10 AUNSW
5AE1
4A ASW
16 A MSW
17 B
VC
11 A MRY
12 A M2
3A M1
8A ECUE
9A SO
1A SI
2A +
1B
IG 6B
P 18 A
BATT
IF IH 6BU1 47
68
3214
11
19 13 12 1B
2
1H
15
1C
8
1K
7
4B +B 2B
TEM+ 11 B
TEM±
10 B TIM+
6ATES
3B TIM±
7A TI S
M
M
10 1 5 6 3 4 1
WB
BR±B
B±R
R
L±W L±W R
GR
B±R
L±W L±Y L±B
R 6
5
BR 5W± L
W±L W
W
GR GR GR B±R
RR R
L±W
L±W
W
R± B
W± B
Y
B
W
BR±B
BR±B
R±WR±Y
R P
V±Y
V± W
B
W
BR±B
BR±B
P
R
R±Y
BR
P± L
R±L
R±B
Y±R
R±W
BR
L±Y
L±B
BR
W±B
60A MAIN
120A ALT 100A AM1F9
FUSE BLOCK 40A
IGSW
B±Y
GR B±R
BR±B
BR15A
ECU± I G 10A
DOME
Fr om A/ T Indicat or SW
< 3±6>
TI L T AND POWER TELESCOPI C ECU30A
POWER
30A
DOOR
TEL ESCO
LONG TILT
UP
TEL ESCO
SHORT TILT
DOWN
MANUAL SW AUTO SW
T I LT POSI TI ON
SENSOR
TI L T CONTROL MOTOR
TELESCOPIC POSITION
SENSOR
TE LE SCOP I C CONT ROL MOTOR No . 1
No . 2
SET
D1 2
DRIVING POSITION
MEMORY AND RETURN
SW
(
SHI ELDED )(
SHI ELEDED)
BATTERY
BR±B
T7
TELESCOPIC
POSI TI ON SENSOR
Power
Source Power Tilt and Power Telescopic
I15
IGNITION SW
6 74
To Unlock Warning SW
[IGNITION SW]< 4±4> < 5±4>
To Door Lock Mot or,
Door Unloc k Detec tion SW and
Door Open Detec tion SW LH< 17±4>
From Remote Cont rol Mirr or ECU
< 10±4> W
T10 A , T11 B
C17
TI LT AND POWER TELESCOPIC UNIT
[COMB. SW]
(
Cont . ne xt pa ge )
5
4
3
2
1
6789101112
12 34 56 78
9 10 1112 13 14 1516 1718
AA
T11 T10
TIL T AND POWER
TELESCOPI C ECU
W±L
Left kick panel Under t he ashtray LH2
1
3
4 1
2
To Parking Brake SW
< 21±2>
GR
( M/T )
(
A/T )
WhereEverybodyKnowsYourName